Article: 217947 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Magnetic Loop !!! Date: Sat, 1 Oct 2005 17:36:49 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Hello Lee, Thanks for letting me know that by giving your magloop half-a-chance it performs according to expectations. You have also demonstrated that the G5RV is not so hot as it is made out to be by salesmen and they who have never tried anything else. No disrespect intended to G5RV himself, now deceased, who claimed only that it had a nice radiation pattern on 14.15 MHz which enabled him to work both Europe and North America from South America without having to climb ladders and change anything. The magloop is by far the most efficient of all the antennas of roughly the same physical size. Both theoretically and in practice. It will do even better if you can get it well above ground in the vertical plane. In the horizontal plane it works best at the higher heights, above surrounding obstructions like buildings. But in such surroundings there is room to erect full-size dipoles anyway, which will obviously do better still. The main disadvantage on the 160 and 80 meter bands is the size, physical and capacitance-wise, of the variable tuning capacitor. You need a vaccuum capacitor of about 1000 pF max. By correct choice of loop dimensions and minimum capacitor setting the 40 meter band can also be covered. On 40 meters a small magloop can be highly efficient. Investigate using program MAGLOOP4. Are you using the small internal coupling loop, about 1/5 diameter of main loop, to match to a 50-ohm feedline? This is the best and most simple way to go, A different ratio small loop diameter is needed for other feedline impedances. The circuit behaves as if the turns ratio on a transformer is being changed. Let us know how your experiments proceed. ---- Reg, G4FGQ. Article: 217948 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sat, 1 Oct 2005 19:33:49 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> "J. Mc Laughlin" wrote > Dear Reg (G4FGQ): > > I note with interest that your note was written in the early afternoon. ========================================== My Dear J. Mc Laughlin, Thank you for your interest in my early afternoon state of health. It is now 19.15 hours and I have just started on a bottle of Sierra Valley, Californian, Ruby Cabernet. > > The subject of my communication is: small (much smaller than a > wavelength) - non-resonant (input impedance almost entirely inductive if one > looks into a single opening in the loop) - horizontal - loop antenna (no > substances with significant magnetic properties are in the vicinity of the > loop antenna) - used to receive incident EM waves (which have both E and H > components). SNRHL receiving antennas > > I do not know the definition of a "magloop." Apparently, such a beastie > comprises a resonant loop antenna. ======================================= "Magloop" describes a small, single-turn, thick conductor, usually made from copper water pipe, circular, hexagonal or square in shape, loop. The two ends of the loop are connected together via a variable capacitor. The capacitor tunes the inductance of the loop to a resonant frequency at which everything happens. The term "magnetic" arises because the near-field of a transmitting loop is mainly magnetic as distinct from the electric field. On receive it is more sensitive the magnetic field than the electric field. ======================================= > No knowledgeable person would disagree that a single tuned network with > a Q of 1000 is "narrow." > > My interest in SNRHL receiving antennas comes from an interest in > practical HF receiving antennas that are resistive to types of noise that > appear only to be present at isolated, open, rural, otherwise-low-noise > sites. The noise involved does not occur in urban areas or even rural sites > with many trees. ===================================== The noise in rural, open, oceanic areas is just the same sort as in built-up, residential, city and industrial areas. It is all random but there is just a lot less of it. An antenna of any sort is just as sensitive to noise as it is to signals provided both noise and signals are coming from the same direction and elevation. ====================================== > > Consider some of the excellent wine from Michigan this evening. This > state, with a coastline almost the same length as that of the island of > Great Britain, produces some excellent products for your enjoyment. > ======================================= Everybody has heard of the State of Michigan with its capital city of Detroit. I have always thought of it as an industrial state similar to my own area of the city of Birmingham and the surrounding Black Country of England. It is the manufacuring areas which produce the REAL wealth of this World of ours. Not forgetting the farmers. Never having had the opportunity to visit Michigan it has not occurred to me that the land could also grow grapes and produce wine. (Actually, we do produce respectable wine here in cool-climate industrial England. But not much of it.) It is now 20.00 hrs and too late to go shopping at my local super-market. Nevertherless, at my next visit I shall keep my eyes open for "Michigan" on the wine bottle labels. ---- Reg, G4FGQ. From Fri Oct 7 11:45:29 EDT 2005 Article: 217949 of rec.radio.amateur.antenna From: Matt Osborn <> Newsgroups: alt.ham-radio.vhf-uhf,rec.radio.amateur.antenna,rec.radio.amateur.dx,rec.radio.amateur.equipment,rec.radio.amateur.policy Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sat, 01 Oct 2005 14:41:19 -0500 Organization: Posted via Supernews, http://www.supernews.com Message-ID: <3iptj1d8gviv3i1agb619ec1pshgovrmav@4ax.com> References: <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <0lqrj159qhmnctjgq3srd8br32uftls2u1@4ax.com> <433dedcd$0$32199$39cecf19@news.twtelecom.net> <7d1sj1ljfil7mk2a45g84havhdhtn0t32b@4ax.com> X-Newsreader: Forte Agent 2.0/32.652 X-No-Archive: yes MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@supernews.com Lines: 15 Path: news1.isis.unc.edu!arclight.uoregon.edu!canoe.uoregon.edu!newsfeed.news.ucla.edu!newsfeed.berkeley.edu!ucberkeley!sn-xit-03!sn-xit-11!sn-xit-08!sn-post-01!supernews.com!corp.supernews.com!not-for-mail Xref: news1.isis.unc.edu alt.ham-radio.vhf-uhf:22947 rec.radio.amateur.antenna:217949 rec.radio.amateur.dx:29648 rec.radio.amateur.equipment:208836 rec.radio.amateur.policy:251318 On Sat, 01 Oct 2005 08:21:47 -0700, Richard Clark wrote: >On Sat, 01 Oct 2005 09:21:31 -0500, Matt Osborn <> wrote: > >>The tale is of two sheep > >Hi Matt, > >Such problems. It's good to see we can agree on at least that much. -- msosborn at msosborn dot com Article: 217950 of rec.radio.amateur.antenna From: LT Subject: Re: Magnetic Loop !!! Date: Sat, 01 Oct 2005 20:57:15 -0000 Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Hi Lee, I'm a little confused about the bandwidth that you're getting. Maybe it can be attributed to losses which widen the SWR bandwidth. That's not necessarily a bad thing. I have used an AEA IsoLoop antenna that is about the same size as your loop antenna but has a low loss butterfly capacitor for tuning 10-30 MHz. On 20 meters the bandwidth is only about 20 or 30KHz(can't remember exactly since I haven't used it for a couple of years). It works great if you park yourself on a frequency but it is a pain to use for hunt and pounce. Besides the null using vertical polarization, is it possible that for your local friend you may have been cross-polarized. Usually direct wave cross-polarization is on the order 20db which accounts for the 2 to 3 S units of change from vertical to horizontal. Have fun with your new toy! 73 LT > Hi Reg.... > > I took my little 1 meter dia ( 10 ft circ ) loop outside lunchtime and > mounted it verticaly 2ft off the lawn and tested it, not expecting > anything special and found that comparing it to the G5RV that there > was no noticable difference between the two!!...my friend and i > switched out our preamps and attenuator in. > > I even turned the loop face on and edge on with a change of 2-3 S > points.. So, needless to say, i am rather impressed with the > performance and bandwidth of 2:1 SWR about 180k.....so much so that i > am thinking seriously of going for a 20 ft circumference or larger for > 80 and 40 metres.... > > Regards. > > Lee....G6ZSG.....Well impressed!!! :-) > > > Article: 217951 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Magnetic Loop !!! Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Date: Sat, 01 Oct 2005 21:01:01 GMT On Sat, 01 Oct 2005 13:42:40 GMT, "Lee" wrote: >I took my little 1 meter dia ( 10 ft circ ) loop outside lunchtime and >mounted it verticaly 2ft off the lawn and tested it, not expecting anything Did your "little loop" grow since your first post... it was 1m in circumfrence in the beginning? Owen -- Article: 217952 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sat, 1 Oct 2005 18:53:26 -0400 Message-ID: <8b50$433f1398$97d558d8$27686@ALLTEL.NET> Nah, I used to beat the crap out of wooses like you and take their lunch money. Enjoyed watching them cry. If I were standing in front of you, you would be peeing your pants and hollering "Mommy". Your type is only brave when behind a teacher or a keyboard. Get a life or get educated enough to use your newsreader correctly so you may avoid apoplexy... "Pat Stevens" wrote in message news:Qby%e.16485$Xl2.3691@twister.nyroc.rr.com... > You probably call the police a nazi, too, when they pull you over for > speeding. How come everyone believes that they don't need to follow the > rules and that when they have it pointed out to them that they are outside > the rules, they are being "picked on." Is that what you were in school? > > "Fred W4JLE" wrote in message > news:7d3a5$433e926c$97d558d8$32550@ALLTEL.NET... > >I bet you were a hall monitor in school... > > > > It must be really boring to have a life that is only enriched by being a > > net > > Nazi. > > Article: 217953 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <433de88a$0$32196$39cecf19@news.twtelecom.net> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sat, 1 Oct 2005 19:00:01 -0400 Message-ID: Richard, if the same 3 were used to design the wheels as the tires, you would never know the difference. PI is really smart in that it knows about both Metric and Inches :>) "Richard Clark" wrote in message news:dhttj1d92o8qhv2m93njjuhvefdbg52tr1@4ax.com... > On Sat, 01 Oct 2005 16:06:08 -0400, Mike Coslo > wrote: > > But pi is exactly 3 in some circles....... > > > > While we are busy putting "intelligent design" into schools, I suggest > >we start putting "faith based mathematics" in next. > > Hi Mike, > > If I recall correctly, the forebears of the untelligent design crowd, > during the scopes monkey trial, attempted to mandate that pi was equal > to 22/7ths. However, I don't see where faith attaches to 22 and 7 was > always a cabalistic device of the middle ages. > > Close enough for as many as 3 would be. > > I would hate to drive on their 13/14/15 inch tires tho'. ;-) > > 73's > Richard Clark, KB7QHC Article: 217954 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Subject: Re: Magnetic Loop !!! Date: Sat, 1 Oct 2005 19:04:39 -0400 Message-ID: What about a fractal magloop Reg? Should be even smaller. :>) "Reg Edwards" wrote in message news:dhmhfg$chb$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com... > The magloop is by far the most efficient of all the antennas of > roughly the same physical size. Both theoretically and in practice. It > will do even better if you can get it well above ground in the > vertical plane. > Article: 217955 of rec.radio.amateur.antenna From: Gene Fuller Subject: Re: Lightning Question References: <3IWdnVBwV9BTkqHeRVn-sw@crocker.com> <1128062984.923437.180830@g49g2000cwa.googlegroups.com> <1128148759.890588.276840@z14g2000cwz.googlegroups.com> Message-ID: Date: Sat, 01 Oct 2005 23:30:49 GMT I have a copy of an article that gives a good overview of the cosmic ray hypothesis. It appeared in the May 2005 issue of Physics Today. The authors are: Alexander V. Gurevich and Kirill P. Zybin. Their affiliation is described as: A.V. Gurevich is the leader and K. P. Zybin is a research scientist in the I. E. Tamm theoretical department at the P. N. Lebedev Physical Institute of the Russian Academy of Sciences in Moscow. I can e-mail a PDF copy (about 250 kB) of the article to anyone who wants one. Send me a message by correcting the rather obvious munge in my e-mail address. As I noted previously, I do not have any particular expertise or vested interest in this cosmic theory, but I do find it interesting. 73, Gene W4SZ nm5k@wt.net wrote: > > > Has nothing to do with cosmic radiation, black holes, etc.. > If that were the case, you would have near constant lightning, > in all kinds of weather. I have no doubt that lightning effects > the ultra high altitudes with the jet and sprites, etc. But I think > it starts from the strike itself, and effects upwards as some kind > of large recharge/discharge mechanism. But thats just my guess. > I really haven't looked into that much. How this guy thinks cosmic > radiation is the key, I dunno... Hummm... Is he a doktor with letters > > after his name? He's not working off a government grant is he? > Inquiring minds wanna know... > MK > Article: 217956 of rec.radio.amateur.antenna From: Walter Maxwell Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> Date: Sat, 01 Oct 2005 19:39:27 -0400 On Sat, 1 Oct 2005 19:33:49 +0000 (UTC), "Reg Edwards" wrote: >======================================= >Everybody has heard of the State of Michigan with its capital city of >Detroit. I have always thought of it as an industrial state similar to >my own area of the city of Birmingham and the surrounding Black >Country of England. It is the manufacuring areas which produce the >REAL wealth of this World of ours. Not forgetting the farmers. >Reg, G4FGQ. > Reg, I grew up in Michigan, and spend 6 mo a year here, the other 6 in Florida. In all the time I've spent in Michigan I wasn't aware that Detroit is the Capitol. When was it moved from Lansing? Perhaps Mac can help you out in this dilemma you're creating. Walt Article: 217957 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sat, 1 Oct 2005 20:41:45 -0400 Message-ID: <11jub2qsovg9gae@corp.supernews.com> References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> Dear Reg (G4FGQ): It is now likely to be past your bed time so this message may be contemplated in the bright, clear morning. I have inserted some items below. -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net "Reg Edwards" wrote in message news:dhmoat$hip$1@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com... > > "J. Mc Laughlin" wrote > > > Dear Reg (G4FGQ): > > > > I note with interest that your note was written in the early > afternoon. > > ========================================== > My Dear J. Mc Laughlin, > > Thank you for your interest in my early afternoon state of health. It > is now 19.15 hours and I have just started on a bottle of Sierra > Valley, Californian, Ruby Cabernet. --- You are commended for your assistance of our unfortunate brethren in California. A good Midwesterner gives thanks at frequent intervals not to be in crammed into California or out East. It is appropriate to observe that the French would have no good grapes were it not for the Californian growers. > > > > The subject of my communication is: small (much smaller than a > > wavelength) - non-resonant (input impedance almost entirely > inductive if one > > looks into a single opening in the loop) - horizontal - loop antenna > (no > > substances with significant magnetic properties are in the vicinity > of the > > loop antenna) - used to receive incident EM waves (which have both E > and H > > components). SNRHL receiving antennas > > > > I do not know the definition of a "magloop." Apparently, such a > beastie > > comprises a resonant loop antenna. > > ======================================= > "Magloop" describes a small, single-turn, thick conductor, usually > made from copper water pipe, circular, hexagonal or square in shape, > loop. The two ends of the loop are connected together via a variable > capacitor. The capacitor tunes the inductance of the loop to a > resonant frequency at which everything happens. > > The term "magnetic" arises because the near-field of a transmitting > loop is mainly magnetic as distinct from the electric field. On > receive it is more sensitive the magnetic field than the electric > field. --- I am obliged to you for providing a definition of "magloop." The critical element of the definition seems to be that a magloop is a loop that is resonated by a reactance. --- I am puzzled by your observation with respect to the term "magnetic" in conjunction with a loop antenna (presumably a loop antenna, whether or not a magloop). You appear to be saying that a loop antenna is more sensitive to the H field than to the E field of an incident EM field. --- Relative to you, I have only been dealing with antennas a short 50 years. However, in that time, I have only encountered antennas that extract a signal from an EM field where the ratio of E to H is well established. My graduate professor, who recently passed away and who wrote The Book on antennas, never mentioned antennas that inherently were sensitive to one component of the incident EM wave. --- Perhaps what you were saying is that one can predict the polarization of an EM wave launched from a loop antenna from knowing its geometry and the observer's orientation with respect to the geometry. This is also true for a doublet and a number of other antennas. > ======================================= > > > No knowledgeable person would disagree that a single tuned > network with > > a Q of 1000 is "narrow." > > > > My interest in SNRHL receiving antennas comes from an interest > in > > practical HF receiving antennas that are resistive to types of noise > that > > appear only to be present at isolated, open, rural, > otherwise-low-noise > > sites. The noise involved does not occur in urban areas or even > rural sites > > with many trees. > > ===================================== > The noise in rural, open, oceanic areas is just the same sort as in > built-up, residential, city and industrial areas. It is all random but > there is just a lot less of it. --- I do not have the verbal skill of Richard Clark, who could find an elegant way to say what needs to be said. Dear Reg, you are wrong. You are wrong because your long and extensive carrier has not placed you in the sites described. Had you spent time out in the sticks, bare of same, you would have encountered the discharging of charged particles into the antenna you were using (or discharging into nearby conductors) producing a prodigious amount of excess noise. The particles are sometimes dust particles, sometimes water droplets, and sometime snow. By far, the greatest limitation on the performance of an HF receiving site in rural, open country is the sudden appearance of this noise. Even at VHF, it is sometimes a limiting factor. State Police posts in Michigan have sometimes not been able to communicate with 100 watt mobiles that were less than 300 meters away because of this noise appearing in a snow storm. (Movement to much higher frequencies and other strategies have alleviated their problem.) --- My experience does not extend to extensive receiving sites out to sea. They might, it they exist at all, not encounter the excess noise. It is also clear that high air humidity may serve to reduce the excess noise. --- Please add to your vast reservoir of knowledge something new. --- > > An antenna of any sort is just as sensitive to noise as it is to > signals provided both noise and signals are coming from the same > direction and elevation. > ====================================== > > > > Consider some of the excellent wine from Michigan this evening. > This > > state, with a coastline almost the same length as that of the island > of > > Great Britain, produces some excellent products for your enjoyment. > > > ======================================= > Everybody has heard of the State of Michigan with its capital city of > Detroit. I have always thought of it as an industrial state similar to > my own area of the city of Birmingham and the surrounding Black > Country of England. It is the manufacuring areas which produce the > REAL wealth of this World of ours. Not forgetting the farmers. --- Well said! Michigan has had the most productive industry in the world. It also has some of the most productive agricultural land - especially for being in the north. However, Michigan (and others) are going through a major change. The advent of fast, inexpensive communication and transportation have seen the movement of vast numbers of manufacturing jobs to areas where wages are low. Many square miles of factories have been pulled-down to bare ground. (Taxes are thus reduced - often next to impossible to sell the land because of unknown pollutants from 90 or more of industrial use.) Ascendant in Michigan are jobs that produce intellectual property, that are involved with higher education, and that are involved with medicine including research. The new worker is different. --- While Detroit is still the largest city, the capital is in Lansing. > > Never having had the opportunity to visit Michigan it has not occurred > to me that the land could also grow grapes and produce wine. > (Actually, we do produce respectable wine here in cool-climate > industrial England. But not much of it.) ---Michigan is almost surrounded by very large lakes that mollify the weather. The west coast of Michigan, in particular, has very productive fruit farming. It is quite possible that few of Michigan's grape products are exported. Thank you for considering another of our products for your evening repast. > > It is now 20.00 hrs and too late to go shopping at my local > super-market. Nevertherless, at my next visit I shall keep my eyes > open for "Michigan" on the wine bottle labels. > ---- > Reg, G4FGQ. > > Article: 217958 of rec.radio.amateur.antenna From: Buther Boy Subject: Where to by random wire (longwire) antennas Date: Sat, 01 Oct 2005 19:59:22 -0500 Message-ID: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> I'm looking at the MFJ-16010, and want to buy some random wire and do some antenna experimenting. Could someone please point me to a link(s) for random wire antennas? Buther Boy -- Remove the word Spam from my e-mail to contact me... http://www.PrivacySig.com/SIGbutherboySpam-gmail-black.png ~ Article: 217959 of rec.radio.amateur.antenna From: Buther Boy Subject: Re: Where to by random wire (longwire) antennas Date: Sat, 01 Oct 2005 20:03:20 -0500 Message-ID: References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> On Sat, 01 Oct 2005 19:59:22 -0500, Buther Boy wrote: >I'm looking at the MFJ-16010, and want to buy some random wire and do >some antenna experimenting. Could someone please point me to a >link(s) for random wire antennas? > >Buther Boy Also, as I am just getting back into the hobby, I need a refresher of sorts. What do I need to buy besides the random wire and antenna tuner. Are there any other supplies that are necessary (besides the radio LOL)? Thanks. Buther Boy -- Remove the word Spam from my e-mail to contact me... http://www.PrivacySig.com/SIGbutherboySpam-gmail-black.png ~ Article: 217960 of rec.radio.amateur.antenna From: mensch90249@yahoo.com Subject: Re: Where to by random wire (longwire) antennas Date: Sat, 01 Oct 2005 18:13:25 -0700 Message-ID: References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> On Sat, 01 Oct 2005 20:03:20 -0500, Buther Boy wrote: >On Sat, 01 Oct 2005 19:59:22 -0500, Buther Boy wrote: > >>I'm looking at the MFJ-16010, and want to buy some random wire and do >>some antenna experimenting. Could someone please point me to a >>link(s) for random wire antennas? >> >>Buther Boy > >Also, as I am just getting back into the hobby, I need a refresher of >sorts. What do I need to buy besides the random wire and antenna >tuner. Are there any other supplies that are necessary (besides the >radio LOL)? > >Thanks. > >Buther Boy My recommendation is to hold off on the MFJ 'tuner' and first put up the antenna and see how it plays. As to where to buy; Lowe's, Home Depot or whatever similar type place will be your best bet for the wire - suggest #12 or #14 stranded just as you would use to wire your house. Insulators can be made from wood, use some 3/4 square cut 3 - 5 inches long with a hole drilled in each end then seal it with several coats of varnish. For more info this article is highly recommended: http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html Good Luck, Howard Article: 217961 of rec.radio.amateur.antenna From: Buther Boy Subject: Re: Where to by random wire (longwire) antennas Date: Sat, 01 Oct 2005 20:30:52 -0500 Message-ID: References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> Howard: I read the article, and would really appreciate it if you would please simplify construction AND installation for me. Step by step, where applicable and if possible. Many thanks in advance. :-) Buther Boy On Sat, 01 Oct 2005 18:13:25 -0700, mensch90249@yahoo.com wrote: >On Sat, 01 Oct 2005 20:03:20 -0500, Buther Boy wrote: > >>On Sat, 01 Oct 2005 19:59:22 -0500, Buther Boy wrote: >> >>>I'm looking at the MFJ-16010, and want to buy some random wire and do >>>some antenna experimenting. Could someone please point me to a >>>link(s) for random wire antennas? >>> >>>Buther Boy >> >>Also, as I am just getting back into the hobby, I need a refresher of >>sorts. What do I need to buy besides the random wire and antenna >>tuner. Are there any other supplies that are necessary (besides the >>radio LOL)? >> >>Thanks. >> >>Buther Boy > >My recommendation is to hold off on the MFJ 'tuner' and first put up >the antenna and see how it plays. As to where to buy; Lowe's, Home >Depot or whatever similar type place will be your best bet for the >wire - suggest #12 or #14 stranded just as you would use to wire your >house. Insulators can be made from wood, use some 3/4 square cut 3 - >5 inches long with a hole drilled in each end then seal it with >several coats of varnish. For more info this article is highly >recommended: >http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html > >Good Luck, >Howard -- Remove the word Spam from my e-mail to contact me... http://www.PrivacySig.com/SIGbutherboySpam-gmail-black.png ~ Article: 217962 of rec.radio.amateur.antenna From: "Pat Stevens" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: Date: Sun, 02 Oct 2005 01:57:05 GMT Ok. So, you were the bully who couldn't follow rules and believe that they never apply to you. So, now you are continuing that ideology in life as you "hide behind your keyboard." Just goes to show, that some people never grow up and never change. "Fred W4JLE" wrote in message news:8b50$433f1398$97d558d8$27686@ALLTEL.NET... > Nah, I used to beat the crap out of wooses like you and take their lunch > money. Enjoyed watching them cry. > > If I were standing in front of you, you would be peeing your pants and > hollering "Mommy". Your type is only brave when behind a teacher or a > keyboard. > > Get a life or get educated enough to use your newsreader correctly so you > may avoid apoplexy... > > > "Pat Stevens" wrote in message > news:Qby%e.16485$Xl2.3691@twister.nyroc.rr.com... >> You probably call the police a nazi, too, when they pull you over for >> speeding. How come everyone believes that they don't need to follow the >> rules and that when they have it pointed out to them that they are >> outside >> the rules, they are being "picked on." Is that what you were in school? >> >> "Fred W4JLE" wrote in message >> news:7d3a5$433e926c$97d558d8$32550@ALLTEL.NET... >> >I bet you were a hall monitor in school... >> > >> > It must be really boring to have a life that is only enriched by being >> > a >> > net >> > Nazi. >> >> > > Article: 217963 of rec.radio.amateur.antenna From: "Pat Stevens" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: Date: Sun, 02 Oct 2005 01:59:35 GMT The controls have already been put in place. The idea of posting on-topic is nothing new and most people find a way to keep themselves within those boundaries. I would imagine that the band plans for the amateur radio frequencies are only a "guide" for you, too, and that you feel that you can transmit in any mode and on any band that you feel fit. Right? "Mike Coslo" wrote in message news:MYSdnVOhLKEzcaPeRVn-gw@adelphia.com... > Matt Osborn wrote: >> On Sat, 01 Oct 2005 00:30:04 GMT, "Pat Stevens" >> wrote: >> >> >>> Your own stupidity is hindering you. Take it to e-mail, moron. >>> >>> wrote in message >>>news:d0krj158a9aifpk3s92eovrr0nupp0mo1u@4ax.com... >>> >>>>Simply avoiding the question? Your blindness hinders me not. >>>> >>>> >>>>-- msosborn at msosborn dot com >> >> >> Nice vocabulary. Need help using your newsreader? > > Pat doesn't like us talking about this, Matt. Seems like everyone is > having a good time, and the posts are pretty civil. I guess some people > like to control others, eh? > > - Mike KB3EIA - Article: 217964 of rec.radio.amateur.antenna From: Buther Boy Subject: Has anyone any experiences with B&W's AP-10A 300 watt portable antenna? Date: Sat, 01 Oct 2005 21:09:27 -0500 Message-ID: It is supposed to work on 2-40 meters, and is located on page 83 of HRO's (hamradio.com) online PDF catalog. Buther Boy -- Remove the word Spam from my e-mail to contact me... http://www.PrivacySig.com/SIGbutherboySpam-gmail-black.png ~ Article: 217965 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sat, 1 Oct 2005 22:23:04 -0400 Message-ID: <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> Do I look like I am "hiding" you twit! I can see not only are you too stupid to use a newsreader, in addition you have no clue as to what can be gleaned from my call. I love upsetting supercillious net Nazis. Makes my day. "Pat Stevens" wrote in message news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... > Ok. So, you were the bully who couldn't follow rules and believe that they > never apply to you. So, now you are continuing that ideology in life as you > "hide behind your keyboard." Article: 217966 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Fractal Antennas References: <1127500565.002715.196800@o13g2000cwo.googlegroups.com> <6muij11sgp4h5hj9u39ndqfir0cocpvkf0@4ax.com> <8fblj1ho8ej0ihucalee6comabmo87h1b3@4ax.com> <11jmc9on86rvfcc@corp.supernews.com> <73063$433c14ac$97d56a13$3806@ALLTEL.NET> Message-ID: Date: Sun, 02 Oct 2005 02:50:16 GMT Mike Coslo wrote: > Indeed. But it is such a misleading term. It gets people to believe > that an antenna which is very inefficient, yet have a low "takeoff > angle" is somehow superior to an antenna that may have a higher TOA, but > may have more overall "oomph" at the same angle as the lower TOA antenna. I agree that it would have been nice if TOA had not been defined that way. What I always attempt to do is state a gain to go with the TOA. -- 73, Cecil http://www.qsl.net/w5dxp Article: 217967 of rec.radio.amateur.antenna Date: Sat, 01 Oct 2005 21:31:28 -0500 From: Tom Ring Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <433de88a$0$32196$39cecf19@news.twtelecom.net> Message-ID: <433f4680$0$32207$39cecf19@news.twtelecom.net> Mike Coslo wrote: > Tom Ring wrote: > >> Richard Clark wrote: >> >>> The question? "What is 6 times 7?" >>> >> >> The question, quoted from the book, is "What do you get when you >> multiply six by nine?". And the answer is still 42. Which is obvious. > > > But pi is exactly 3 in some circles....... > > While we are busy putting "intelligent design" into schools, I > suggest we start putting "faith based mathematics" in next. > > - Mike KB3EIA - That wasn't my point. I thought some of you might figure out why. I am quite disappointed to tell the truth. 6 x 9 = 42 It's not that tough, unless you can't think out of at least one box. And those that figured it out fron "The Book", please do not comment. tom K0TAR Article: 217968 of rec.radio.amateur.antenna From: "KØHB" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: Date: Sun, 02 Oct 2005 02:37:19 GMT "Pat Stevens" wrote > The controls have already been put in place. The idea of posting on-topic is > nothing new and most people find a way to keep themselves within those > boundaries. Pat, usenet has no controls "put in place" (except on moderated newsgroups). Each newsgroup is commissioned for a stated purpose and should generally be followed, but sometimes the exhuberance of the moment causes us to stray off into other areas. S#!t happens! > I would imagine that the band plans for the amateur radio frequencies are only > a "guide" for you, too, and that you feel that you can transmit in any mode > and on any band that you feel fit. Right? Bandplans are voluntary "guides", and generally make good sense. Times happen, however, when there are good reasons to deviate from a particualr bandplan. So long as the mode/band is FCC-legal and I have a personally-acceptable reason, you're right --- I >>do<< feel that I can take a one-time exception to the bandplan guidelines. 73, de Hans, K0HB Article: 217969 of rec.radio.amateur.antenna From: mensch90249@yahoo.com Subject: Re: Where to by random wire (longwire) antennas Date: Sat, 01 Oct 2005 20:55:22 -0700 Message-ID: <4rluj11u09d3f8fnjsrdgq8f191gjc4sl8@4ax.com> References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> On Sat, 01 Oct 2005 20:30:52 -0500, Buther Boy wrote: >Howard: > >I read the article, and would really appreciate it if you would please >simplify construction AND installation for me. Step by step, where >applicable and if possible. > >Many thanks in advance. :-) > >Buther Boy Buther, I'm going to refer you to another website that has further explained it and offers some illustrations - a picture is worth....... Yes, it's a bit of laziness on my part and also an admission that I'm not so hot at writing instructions. A few tips though: 1) Insulators; wire antenna attached to one hole, rope to the other - the rope ties off to a support such as a mast, tree or house. 2) Lead in wire/transmission line; the wire can come directly to the house but can pick up lots of noise, using coaxial cable (and a suitable ground) can help reduce this - attach the center conductor to the antenna and the shield (braided wire just under the plastic jacket) to ground. if for listening only go ahead and use 75 ohm cable as you would buy for your cable or satellite TV system. 3) Ground; a metal rod, typically 8 feet long, driven into the ground; you can use the ground rod for your home electrical. 4) Keep your antenna as far from power lines as you can and perpendicular to the power lines (if nearby) can help to reduce noise vs parallel to them. Here's the site promised: http://www.kc7nod.20m.com/random_wire.htm Thanks to KC7NOD for taking the time to put this info on his site. Also, don't forget that Google is your friend, type in 'random wire antenna' and you will receive a wealth of other info. Howard Article: 217970 of rec.radio.amateur.antenna From: "Lee" References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Subject: Re: Magnetic Loop !!! Message-ID: <%GJ%e.37888$VI6.3384@fe1.news.blueyonder.co.uk> Date: Sun, 02 Oct 2005 04:51:07 GMT "Owen Duffy" wrote in message news:ntttj1to6mofbfp7q25gvu7ogbgcvmhrot@4ax.com... > On Sat, 01 Oct 2005 13:42:40 GMT, "Lee" > wrote: > > > >I took my little 1 meter dia ( 10 ft circ ) loop outside lunchtime and > >mounted it verticaly 2ft off the lawn and tested it, not expecting anything > > Did your "little loop" grow since your first post... it was 1m in > circumfrence in the beginning? > > Owen > -- You`re right Owen, i did state that didn`t i?...it was a typo of course,Heh heh, it should read "10Foot circumference approx 1 meter dia"....... Thanks for telling me ...... Lee......G6ZSG........ Article: 217971 of rec.radio.amateur.antenna From: "Lee" References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Subject: Re: Magnetic Loop !!! Message-ID: Date: Sun, 02 Oct 2005 05:27:08 GMT "Reg Edwards" wrote in message news:dhmhfg$chb$1@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com... > Hello Lee, > > Thanks for letting me know that by giving your magloop half-a-chance > it performs according to expectations. > > You have also demonstrated that the G5RV is not so hot as it is made > out to be by salesmen and they who have never tried anything else. Are you using the small internal coupling loop, about 1/5 diameter of > main loop, to match to a 50-ohm feedline? This is the best and most > simple way to go, No. i`m using a `gamma` match, if you can call it that....the matching loop comes next. Wonder if a coaxial gamma match would work as i`m a staunch believer....(could put that principle to use for the capacitor tuning instead of a butterfly variable......) Can`t get on with other types of loading, too fiddly!. Regards.... Lee...G6ZSG....... > > A different ratio small loop diameter is needed for other feedline > impedances. The circuit behaves as if the turns ratio on a > transformer is being changed. > > Let us know how your experiments proceed. > ---- > Reg, G4FGQ. > > Article: 217972 of rec.radio.amateur.antenna From: "Lee" References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> Subject: Re: Magnetic Loop !!! Message-ID: <6wK%e.38996$VI6.27383@fe1.news.blueyonder.co.uk> Date: Sun, 02 Oct 2005 05:47:46 GMT "LT" wrote in message news:Xns96E28DF5645D2groupgroupcom@216.168.3.50... > Hi Lee, > > I'm a little confused about the bandwidth that you're getting. Maybe it > can be attributed to losses which widen the SWR bandwidth. That's not > necessarily a bad thing. I have used an AEA IsoLoop antenna that is > about the same size as your loop antenna but has a low loss butterfly > capacitor for tuning 10-30 MHz. On 20 meters the bandwidth is only about > 20 or 30KHz(can't remember exactly since I haven't used it for a couple > of years). It works great if you park yourself on a frequency but it is > a pain to use for hunt and pounce. Yes, of course that should have read 2.5 : 1 SWR which is better than my `loaded` half size G5RV on 80 at about 100kcs 2.5 : 1 SWR....... > > Besides the null using vertical polarization, is it possible that for > your local friend you may have been cross-polarized. Usually direct wave > cross-polarization is on the order 20db which accounts for the 2 to 3 S > units of change from vertical to horizontal. My `friend has a quarter wave vertical for 20 and the loop was physically vertical ....also, my G5RV is sloping...... > > Have fun with your new toy! Thanks, i am...... ;-) Lee....G6ZSG...... > > 73 LT <7iHZe.260$Aw.4524@typhoon.sonic.net> <73mlj158ae210i2vutdik3hg5t0987jlsn@4ax.com> From: Rockinghorse Winner Message-ID: Date: Sun, 02 Oct 2005 05:52:50 GMT Bob Miller writes: >On Wed, 28 Sep 2005 14:14:51 GMT, Cecil Moore wrote: >>Bob Miller wrote: >>> The instruction book I got with my mfj 989c tuner has a section on >>> ladder line lengths to gravitate to, or avoid, depending on band. It >>> can be downloaded free from the mfj web site. >> >>Hopefully, the lengths to avoid are associated with specific >>loads. Avoiding 1/4WL of ladder-line when feeding a 1/2WL >>dipole may be good advice but 1/4WL of ladder-line is ideal >>for feeding a one wavelength dipole. >They're fairly specific about loads -- their manual is at >http://www.mfjenterprises.com/products.php?prodid=MFJ-989C with pages >7 and 8 talking about feedline lengths. >bob >k5qwg Wow! I'll have a look a this ASAP. -- R*Horse rwinner.blogspot.com Article: 217974 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Magnetic Loop !!! Date: Sun, 2 Oct 2005 06:38:26 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> > What about a fractal magloop Reg? Should be even smaller. :>) > This is a case of a fractal GUARANTEED to perform worse than the basic antenna in all respects. That is unless a simple circle can be considered to be a zero-zero-order fractal. Article: 217975 of rec.radio.amateur.antenna From: David Subject: Tables of Er for various metal tubes ? Message-ID: <0xL%e.4865$U51.3234@news-server.bigpond.net.au> Date: Sun, 02 Oct 2005 06:57:00 GMT Does anyone know where I can find Er tables for various type and diameter of metal tubing so I can calculate Velocity coefficient Vp ? Thanks in advance Regards David Article: 217976 of rec.radio.amateur.antenna From: David Subject: Help with Sleeve Dipole Message-ID: Date: Sun, 02 Oct 2005 07:16:01 GMT I am a little confused with calculation of appropriate length of metal tubing used in a sleeve antenna design (the 1/4 wave section). I understand that as RF travels through various mediums, Velocity of the wave slows down relative to Er of the material. So for coax the wavelength would be say 0.66 Lambda. With the tubing over a coaxial cable though it seems there is Vp related to the dielectric formed between the sleeve and the outer sheath of the coax cable but also the Metal has an Er value. 1. Do you need to count for both these when calculate how the tube should be. 2. Is there relationship that needs to be considered between sleeve length and distance between sleeve and coax (ie. If the sleeve is made larger diameter does it effect the length required for the tube or is this still defined strictly by Er) also, Does the diameter of the tube effect the impedance ? The specific example is RG174 Coax cable vertical dipole. The top radiating element is 1/4 long. At the bottom of this element is a length of RG174 Coax. 1/4 wave length of this coax has a 5/32 Brass sleeve. The sleeve is soldered to the RG174 coax at the point where the coax meets the top 1/4 wave element. I need to understand what needs to be used to calculate the length of Brass tubing sleeve given the tubing diameter is 5/32 and besides air, the outer sheath of the RG174 is also between the sleeve and Earth braid. Is the diameter of the tubing critical (will it impact adversely on SWR looking into this antenna). The final point would be if I place some ferrite rings across the coax below the sleeve, will this improve SWR ? Thanks Regards David Article: 217977 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sun, 2 Oct 2005 07:54:05 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> Walt, We are all sentimentally attached to the area where we were born. I find it intriguing you were brought up in the same sort of industrial region as I was dragged up in. There are a few descriptive paragraphs in "A bit about Reg" in my website. Please forgive me for assuming the largest city of Detroit to be the political capital of Michigan when it is actually Lansing. Again there is a similarity. The political capital of Warwickshire is not the largest city of Birmingham but the small ancient town of Warwick with its castle, not far from Shakespeare's Stratford-upon-Avon. Is Michigan named after an Indian tribe? ---- Reg. Article: 217978 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Magnetic Loop !!! Message-ID: <252vj1p09echnki252ss6839q778pf3rc6@4ax.com> References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <6wK%e.38996$VI6.27383@fe1.news.blueyonder.co.uk> Date: Sun, 02 Oct 2005 08:01:27 GMT On Sun, 02 Oct 2005 05:47:46 GMT, "Lee" wrote: >Yes, of course that should have read 2.5 : 1 SWR which is better than my >`loaded` half size G5RV on 80 at about 100kcs 2.5 : 1 SWR....... What is a "'loaded' half size G5RV"? Googling for info, I see a few suppliers with loading coils for a half size G5RV (complete with instructions), but could not find an article with physical dimensions and loading coil characteristics. Is this a "proprietary" antenna, not open to independent analysis. In its "normal" mode, a (full size) G5RV has feed system losses on 160m like cricket scores. Intuition suggests that a half-size G5RV (where everything is scaled to 50%) will have similarly appalling performance on 80m. Has anyone seen details of the loading coils for this "loaded half-sized G5RV', or models of its performance? Owen -- Article: 217979 of rec.radio.amateur.antenna From: David Subject: Re: Help with Sleeve Dipole References: <3d3vj1lvc8tsg4mj90euuk9shdfrecp4mc@4ax.com> Message-ID: Date: Sun, 02 Oct 2005 08:18:01 GMT Richard, Thanks for the feedback. No problem with the failing issue, plenty of that going on. The way I see it though is that if I can add some knowledge to my experimentation then at least I can "play" with some hope of moving to a solution in the right direction. Richard Clark wrote: > On Sun, 02 Oct 2005 07:16:01 GMT, David wrote: > > >>I need to understand what needs to be used to calculate the length of >>Brass tubing sleeve given the tubing diameter is 5/32 and besides air, >>the outer sheath of the RG174 is also between the sleeve and Earth >>braid. Is the diameter of the tubing critical (will it impact adversely >>on SWR looking into this antenna). > > > Hi David, > > The Er of the metal is not something that comes quickly to mind > (especially this late at night). Besides, it sounds like what you are > describing is the radial component which would be fantastically small > (many decimal places, not simply tens of percent). > > It also seems like your application is for UHF (you need to be more > specific). This makes such "calculations" little better than SWAGs. > It doesn't take much to be way off. What is even more confounding is > your problem contains a hidden trap. > > The sleeve of brass that drops below the feed point is embracing the > jacket of the RG174. THIS constitutes the dielectric constant of > interest and is a material that is different from the insulator of the > inner line. Even more, and as you note above, there is some air mixed > in to really gum up the back of the napkin calculations. This is the > G of the SWAG. > > Worst yet, some jacket material is actually quite lossy, or so it has > been reported - another G of the SWAG. > > All-in-all, what you need to do is build one and measure it. No doubt > that will lead to another trail of tears. On the other hand, there is > nothing so stimulating to learning than pain. Most of my best > subjects centered on projects I thoroughly screwed up. > > As the saying goes: > "If you haven't failed, you aren't trying hard enough." > > 73's > Richard Clark, KB7QHC Article: 217980 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sun, 2 Oct 2005 10:02:09 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> <11jub2qsovg9gae@corp.supernews.com> Michigan has had the most productive industry in the world. > It also has some of the most productive agricultural land - especially for > being in the north. However, Michigan (and others) are going through a > major change. The advent of fast, inexpensive communication and > transportation have seen the movement of vast numbers of manufacturing jobs > to areas where wages are low. Many square miles of factories have been > pulled-down to bare ground. (Taxes are thus reduced - often next to > impossible to sell the land because of unknown pollutants from 90 or more of > industrial use.) Ascendant in Michigan are jobs that produce intellectual > property, that are involved with higher education, and that are involved > with medicine including research. The new worker is different. > ========================================= Dear J. Birmingham and the Black Country has suffered a similar fate. Once upon a time EVERYTHING was made in Birmingham. I began work at the age of 14 in an electric motor factory. (I've never met a university professor.) Factories have now been converted to museums as an adjunct to the tourist trade. Only this very week, the last of the once-upon-a-time many Black Country iron foundries poured the last few tons of molten iron from its furnaces. Sadly, three months back the last of the 100-year old motor factories, which started with bicycles, closed its gates rendering 15,000 people redundent. Motor production is to continue in China. Not that I have anything against the enterprising, hard-working Chinese who bought the factory complete with the intellectual property. Good luck to 'em. The rot set in with Lady Maggie Thatcher who favoured the so-called 'service industries'. Now we have Blair who's selling off the Health Service and has loaned the British Army, free of charge, to the Americans. But we can't get rid of him until Bush has gone. Now back to, the always with us, SWR. ;o) ---- Yours, Reg. Article: 217981 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Tables of Er for various metal tubes ? Date: Sun, 2 Oct 2005 10:54:25 +0000 (UTC) Message-ID: References: <0xL%e.4865$U51.3234@news-server.bigpond.net.au> "David" wrote > Does anyone know where I can find Er tables for various type and diameter > of metal tubing so I can calculate Velocity coefficient Vp ? > ===================================== The velocity factor of any conductor, including tubes, depends only on what surrounds it. If the surroundings are air, which is mainly oxygen and nitrogen, then the VF = 1.00, equivalent, in metric units, to a velocity of 300 metres per micro-second. Or in ancient, old-fashioned units, it is the far-less-convenient 669600000 miles per hour, give or take a few 100,000 miles. Who cares? --- Reg. Article: 217982 of rec.radio.amateur.antenna From: Buther Boy Subject: Re: Where to by random wire (longwire) antennas Date: Sun, 02 Oct 2005 06:59:32 -0500 Message-ID: <1pivj1dpef92l4b61vlbqe03ravkj3dfbm@4ax.com> References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> <4rluj11u09d3f8fnjsrdgq8f191gjc4sl8@4ax.com> Howard: I somehow "dreamed" of being able to hide this random wire in my house and tune it up, but that is looking more improbable by the minute. I live in a town home and have no yard. Things don't look good, but I have an excellent idea of how this all works. I appreciate your help, Howard, and thanks for the detailed explanations. Buther Boy On Sat, 01 Oct 2005 20:55:22 -0700, mensch90249@yahoo.com wrote: >On Sat, 01 Oct 2005 20:30:52 -0500, Buther Boy wrote: > >>Howard: >> >>I read the article, and would really appreciate it if you would please >>simplify construction AND installation for me. Step by step, where >>applicable and if possible. >> >>Many thanks in advance. :-) >> >>Buther Boy > >Buther, >I'm going to refer you to another website that has further explained >it and offers some illustrations - a picture is worth....... > >Yes, it's a bit of laziness on my part and also an admission that I'm >not so hot at writing instructions. A few tips though: >1) Insulators; wire antenna attached to one hole, rope to the other - >the rope ties off to a support such as a mast, tree or house. >2) Lead in wire/transmission line; the wire can come directly to the >house but can pick up lots of noise, using coaxial cable (and a >suitable ground) can help reduce this - attach the center conductor to >the antenna and the shield (braided wire just under the plastic >jacket) to ground. if for listening only go ahead and use 75 ohm >cable as you would buy for your cable or satellite TV system. >3) Ground; a metal rod, typically 8 feet long, driven into the ground; >you can use the ground rod for your home electrical. >4) Keep your antenna as far from power lines as you can and >perpendicular to the power lines (if nearby) can help to reduce noise >vs parallel to them. > >Here's the site promised: http://www.kc7nod.20m.com/random_wire.htm >Thanks to KC7NOD for taking the time to put this info on his site. >Also, don't forget that Google is your friend, type in 'random wire >antenna' and you will receive a wealth of other info. > >Howard -- Remove the word Spam from my e-mail to contact me... http://www.PrivacySig.com/SIGbutherboySpam-gmail-black.png ~ Article: 217983 of rec.radio.amateur.antenna From: "Mike" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sun, 2 Oct 2005 08:21:11 -0400 Message-ID: <433fd30a@news.usenetzone.com> I think he was pointing out that he is hiding about as well as you are hiding. "Fred W4JLE" wrote in message news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... > Do I look like I am "hiding" you twit! > > I can see not only are you too stupid to use a newsreader, in addition you > have no clue as to what can be gleaned from my call. > > I love upsetting supercillious net Nazis. Makes my day. > > "Pat Stevens" wrote in message > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... >> Ok. So, you were the bully who couldn't follow rules and believe that > they >> never apply to you. So, now you are continuing that ideology in life as > you >> "hide behind your keyboard." > > _________________________________________ Usenet Zone Free Binaries Usenet Server More than 140,000 groups Unlimited download http://www.usenetzone.com to open account Article: 217984 of rec.radio.amateur.antenna From: David Subject: Re: Tables of Er for various metal tubes ? References: <0xL%e.4865$U51.3234@news-server.bigpond.net.au> Message-ID: Date: Sun, 02 Oct 2005 13:13:04 GMT OK, so the electrical wavelength of the tube will only be effected by the dielectric material and it does not make any difference how large the gap is between the Sleeve and the Coax ? The frequency of operation is 920 MHz. Do you happen to know what the covering is made of on the outer sheath of RG174 ? The cable I have has a stranded inner core and seems to have a PFTE dielectric. (Doesn't melt at all when soldering so I assume this is what it is). Reg Edwards wrote: > "David" wrote > >>Does anyone know where I can find Er tables for various type and > > diameter > >>of metal tubing so I can calculate Velocity coefficient Vp ? >> > > ===================================== > The velocity factor of any conductor, including tubes, depends only on > what surrounds it. > > If the surroundings are air, which is mainly oxygen and nitrogen, then > the VF = 1.00, equivalent, in metric units, to a velocity of 300 > metres per micro-second. Or in ancient, old-fashioned units, it is the > far-less-convenient 669600000 miles per hour, give or take a few > 100,000 miles. Who cares? > --- > Reg. > > Article: 217985 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: Has anyone any experiences with B&W's AP-10A 300 watt portable antenna? Message-ID: References: Date: Sun, 02 Oct 2005 13:34:03 GMT On Sat, 01 Oct 2005 21:09:27 -0500, Buther Boy wrote: >It is supposed to work on 2-40 meters, and is located on page 83 of >HRO's (hamradio.com) online PDF catalog. > >Buther Boy 25 years ago, I had one in a 3rd story apartment. I mounted the whip in a window, about 20 feet up. It worked reasonably well. I was able to tune it up on all bands, including 40 meters. The key is to adjust the length of the counterpoise wire for each frequency you tune up -- I had the wire on a metal spool, and rolled or unrolled the wire till I had low SWR. That wire is hot with RF, so I had a hot wire running across the apartment rug, and you have to watch that. Since you're in a townhouse, you'll be able to ground your station, which I was not able to do in the apartment, so you'll be ahead on that count. For limited space, it's a pretty neat setup, and you can make contacts with it; not as well as with a dipole outdoors, but it works. bob k5qwg Article: 217986 of rec.radio.amateur.antenna From: Bob Miller Subject: Re: Where to by random wire (longwire) antennas Message-ID: References: <90cuj1pqh9pmiemvrl80tq6skp0vrpgg6d@4ax.com> Date: Sun, 02 Oct 2005 13:42:29 GMT On Sat, 01 Oct 2005 19:59:22 -0500, Buther Boy wrote: >I'm looking at the MFJ-16010, and want to buy some random wire and do >some antenna experimenting. Could someone please point me to a >link(s) for random wire antennas? > >Buther Boy Get your tuner, get a 500 foot roll of #14 insulated wire from Lowes or Home Depot (about $30), order a copy of the ARRL Antenna Book from their web site for the particulars on random or long wires, and you'll be all set. bob k5qwg Article: 217987 of rec.radio.amateur.antenna From: "Dave VanHorn" Subject: Vertical colinear Message-ID: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Date: Sun, 2 Oct 2005 09:15:26 -0500 I'm a bit confused over the construction of a vertical colinear. The docs I've seen all are more or less the same, alternating half-wave sections of coax or hardline. The thing that's bending my head, is that there's a velocity factor inside the coax, that presumably isn't there on the outside. So, while a given section is a half wave on the outside, it's probably more like 3/4 wave inside. My understanding is that we are trying to get to a series of dipoles all fed in phase, and yet this seems like it's not accomplishing that. What am I missing? Article: 217988 of rec.radio.amateur.antenna From: "Caveat Lector" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <433fd30a@news.usenetzone.com> Subject: Re: Hams to the Rescue Message-ID: <%zS%e.17526$mH.6909@fed1read07> Date: Sun, 2 Oct 2005 07:58:08 -0700 To get back to the subject title -- take a look at this excellent website http://www.wx4nhc.org/ -- CL -- I doubt, therefore I might be ! Article: 217989 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <433fd30a@news.usenetzone.com> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sun, 2 Oct 2005 11:21:21 -0400 Message-ID: <26afc$433ffb24$97d558d8$6525@ALLTEL.NET> I don't really care, he bores me with his Damyankee, liberal attitude. If there are no rules to control your every move, they will make up some, and get then upset when you don't follow them. "Mike" wrote in message news:433fd30a@news.usenetzone.com... > I think he was pointing out that he is hiding about as well as you are > hiding. > "Fred W4JLE" wrote in message > news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... > > Do I look like I am "hiding" you twit! > > > > I can see not only are you too stupid to use a newsreader, in addition you > > have no clue as to what can be gleaned from my call. > > > > I love upsetting supercillious net Nazis. Makes my day. > > > > "Pat Stevens" wrote in message > > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... > >> Ok. So, you were the bully who couldn't follow rules and believe that > > they > >> never apply to you. So, now you are continuing that ideology in life as > > you > >> "hide behind your keyboard." > > > > > > > _________________________________________ > Usenet Zone Free Binaries Usenet Server > More than 140,000 groups > Unlimited download > http://www.usenetzone.com to open account Article: 217990 of rec.radio.amateur.antenna From: "Pat Stevens" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: Date: Sun, 02 Oct 2005 16:27:17 GMT Hey, Fred, Does this ring a bell? Why do you feel this group would be any different than the one you posted the following message to? Re: Man, Mr. bush Jr. sure is wicked evil eh? by "w4jle" Apr 22, 2004 at 07:13 PM Take this crap to alt.wewearaluminimum.hats Any body forwarding this much crap either is being paid to do it, or seriously needs to get a life! -- W4jle.com - Home of the Professional Curmudgeon "Fred W4JLE" wrote in message news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... > Do I look like I am "hiding" you twit! > > I can see not only are you too stupid to use a newsreader, in addition you > have no clue as to what can be gleaned from my call. > > I love upsetting supercillious net Nazis. Makes my day. > > "Pat Stevens" wrote in message > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... >> Ok. So, you were the bully who couldn't follow rules and believe that > they >> never apply to you. So, now you are continuing that ideology in life as > you >> "hide behind your keyboard." > > Article: 217991 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Help with Sleeve Dipole Date: Sun, 02 Oct 2005 12:03:12 -0500 Message-ID: <11k04mh9vbli6d1@corp.supernews.com> References: David wrote: > I am a little confused with calculation of appropriate length of metal > tubing used in a sleeve antenna design (the 1/4 wave section). > > I understand that as RF travels through various mediums, Velocity of the > wave slows down relative to Er of the material. So for coax the > wavelength would be say 0.66 Lambda. > > With the tubing over a coaxial cable though it seems there is Vp related > to the dielectric formed between the sleeve and the outer sheath of the > coax cable but also the Metal has an Er value. > > 1. Do you need to count for both these when calculate how the tube > should be. > 2. Is there relationship that needs to be considered between sleeve > length and distance between sleeve and coax (ie. If the sleeve is made > larger diameter does it effect the length required for the tube or is > this still defined strictly by Er) also, Does the diameter of the tube > effect the impedance ? > > The specific example is RG174 Coax cable vertical dipole. The top > radiating element is 1/4 long. At the bottom of this element is a length > of RG174 Coax. 1/4 wave length of this coax has a 5/32 Brass sleeve. The > sleeve is soldered to the RG174 coax at the point where the coax meets > the top 1/4 wave element. > I need to understand what needs to be used to calculate the length of > Brass tubing sleeve given the tubing diameter is 5/32 and besides air, > the outer sheath of the RG174 is also between the sleeve and Earth > braid. Is the diameter of the tubing critical (will it impact adversely > on SWR looking into this antenna). > > The final point would be if I place some ferrite rings across the coax > below the sleeve, will this improve SWR ? > > Thanks > > Regards > > David David; That's why they call it the ART of antenna design. First you make the best mathematical calculations you can then you start cutting wire/tubing. Make your lengths slightly longer than the math says then prune the lengths until the antenna works the way you think it should. There are so many variables in antennas that this is the only practical way to make a new one. Once you find your optimal lengths you can make more to the same specs. However remember that just like in housing antenna's depend on three things: location, location, location and have to be custom adjusted for each site. Dave WD9BDZ Article: 217992 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sun, 2 Oct 2005 13:14:15 -0400 Message-ID: <11k05blgo2vgq65@corp.supernews.com> References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> <11jub2qsovg9gae@corp.supernews.com> Dear Reg: In both of our countries, major changes are occurring. In the truly creative sphere, the English speaking countries are still ahead. Education in the "hard" subjects is critical. Well now, Reg, you have at last met (via the Internet) an actual university professor of electrical engineering. 73, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net "Reg Edwards" wrote in message news:dhob71$stq$1@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com... > Michigan has had the most productive industry in the world. > > It also has some of the most productive agricultural land - > especially for > > being in the north. However, Michigan (and others) are going > through a > > major change. The advent of fast, inexpensive communication and > > transportation have seen the movement of vast numbers of > manufacturing jobs > > to areas where wages are low. Many square miles of factories have > been > > pulled-down to bare ground. (Taxes are thus reduced - often next to > > impossible to sell the land because of unknown pollutants from 90 years or > more of > > industrial use.) Ascendant in Michigan are jobs that produce > intellectual > > property, that are involved with higher education, and that are > involved > > with medicine including research. The new worker is different. > > > ========================================= > Dear J. > > Birmingham and the Black Country has suffered a similar fate. Once > upon a time EVERYTHING was made in Birmingham. I began work at the age > of 14 in an electric motor factory. (I've never met a university > professor.) Factories have now been converted to museums as an adjunct > to the tourist trade. > > Only this very week, the last of the once-upon-a-time many Black > Country iron foundries poured the last few tons of molten iron from > its furnaces. Sadly, three months back the last of the 100-year old > motor factories, which started with bicycles, closed its gates > rendering 15,000 people redundent. Motor production is to continue in > China. Not that I have anything against the enterprising, hard-working > Chinese who bought the factory complete with the intellectual > property. Good luck to 'em. > > The rot set in with Lady Maggie Thatcher who favoured the so-called > 'service industries'. Now we have Blair who's selling off the Health > Service and has loaned the British Army, free of charge, to the > Americans. But we can't get rid of him until Bush has gone. > > Now back to, the always with us, SWR. ;o) > ---- > Yours, Reg. > > Article: 217993 of rec.radio.amateur.antenna From: "Dave VanHorn" References: <11k04mh9vbli6d1@corp.supernews.com> Subject: Re: Help with Sleeve Dipole Message-ID: Date: Sun, 2 Oct 2005 12:26:00 -0500 >> With the tubing over a coaxial cable though it seems there is Vp related >> to the dielectric formed between the sleeve and the outer sheath of the >> coax cable but also the Metal has an Er value. >From what I understand, the RF will be traveling on the outside of the sleeve, and won't "see" the internals at all. So, the sleeve ends up as a 1/4 wavelength stub. Is the diameter of the tubing critical (will it impact adversely >> on SWR looking into this antenna). It shouldn't be >> The final point would be if I place some ferrite rings across the coax >> below the sleeve, will this improve SWR ? Not if the sleeve is doing it's job. The sleeve's open end should look like a short at the operating frequency, and keep RF off the feedline. >> Thanks >> >> Regards >> >> David > David; > > That's why they call it the ART of antenna design. First you make the > best mathematical calculations you can then you start cutting wire/tubing. > Make your lengths slightly longer than the math says then prune the > lengths until the antenna works the way you think it should. > > There are so many variables in antennas that this is the only practical > way to make a new one. Once you find your optimal lengths you can make > more to the same specs. However remember that just like in housing > antenna's depend on three things: location, location, location and have to > be custom adjusted for each site. > > Dave WD9BDZ Article: 217994 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sun, 2 Oct 2005 14:30:58 -0400 Message-ID: <2e4ae$43402795$97d558d8$23323@ALLTEL.NET> Did we cause you to spend two days googling newsgroups? You could have found much better examples, I have been getting after net nazis since the ARPA days. Your still a damnyankee liberal twit. "Pat Stevens" wrote in message news:FTT%e.17504$Xl2.16932@twister.nyroc.rr.com... > Hey, Fred, > Does this ring a bell? Why do you feel this group would be any different > than the one you posted the following message to? > > Re: Man, Mr. bush Jr. sure is wicked evil eh? > by "w4jle" Apr 22, 2004 at 07:13 PM > > > Take this crap to alt.wewearaluminimum.hats > > Any body forwarding this much crap either is being paid to do it, or > seriously needs to get a life! > > > -- > W4jle.com - Home of the Professional Curmudgeon > > > > > "Fred W4JLE" wrote in message > news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... > > Do I look like I am "hiding" you twit! > > > > I can see not only are you too stupid to use a newsreader, in addition you > > have no clue as to what can be gleaned from my call. > > > > I love upsetting supercillious net Nazis. Makes my day. > > > > "Pat Stevens" wrote in message > > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... > >> Ok. So, you were the bully who couldn't follow rules and believe that > > they > >> never apply to you. So, now you are continuing that ideology in life as > > you > >> "hide behind your keyboard." > > > > > > Article: 217995 of rec.radio.amateur.antenna From: "Pat Stevens" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <2e4ae$43402795$97d558d8$23323@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: Date: Sun, 02 Oct 2005 19:21:15 GMT No, I only spent a couple of minutes looking. I thought it was interesting that the shoe is now on the other foot, for you. Found your page interesting, too. However, I find it ironic that you call me a yankee. I have been trying to shed the southerner image here with my friends and coworkers ever since I moved up here from Myrtle Beach, after retiring from the Air Force. I grew up in Beaufort, SC, near the Naval Hospital. Most people say that I still have the accent. "Fred W4JLE" wrote in message news:2e4ae$43402795$97d558d8$23323@ALLTEL.NET... > Did we cause you to spend two days googling newsgroups? You could have > found > much better examples, I have been getting after net nazis since the ARPA > days. Your still a damnyankee liberal twit. > > > "Pat Stevens" wrote in message > news:FTT%e.17504$Xl2.16932@twister.nyroc.rr.com... >> Hey, Fred, >> Does this ring a bell? Why do you feel this group would be any different >> than the one you posted the following message to? >> >> Re: Man, Mr. bush Jr. sure is wicked evil eh? >> by "w4jle" Apr 22, 2004 at 07:13 PM >> >> >> Take this crap to alt.wewearaluminimum.hats >> >> Any body forwarding this much crap either is being paid to do it, or >> seriously needs to get a life! >> >> >> -- >> W4jle.com - Home of the Professional Curmudgeon >> >> >> >> >> "Fred W4JLE" wrote in message >> news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... >> > Do I look like I am "hiding" you twit! >> > >> > I can see not only are you too stupid to use a newsreader, in addition > you >> > have no clue as to what can be gleaned from my call. >> > >> > I love upsetting supercillious net Nazis. Makes my day. >> > >> > "Pat Stevens" wrote in message >> > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... >> >> Ok. So, you were the bully who couldn't follow rules and believe that >> > they >> >> never apply to you. So, now you are continuing that ideology in life > as >> > you >> >> "hide behind your keyboard." >> > >> > >> >> > > Article: 217996 of rec.radio.amateur.antenna From: "Jerry Martes" References: <1128269672.814425.42830@g14g2000cwa.googlegroups.com> Subject: Re: Need Suggestions for a Relay Source Message-ID: <4tW%e.3427$kl3.1494@trnddc08> Date: Sun, 02 Oct 2005 19:23:44 GMT "Brian Kelly" wrote in message news:1128269672.814425.42830@g14g2000cwa.googlegroups.com... > I'm looking for a source for small inexpensive 12VDC relays which are > usable for cold-switching ~200W of RF at frequencies up to 30 Mhz. The > relays would be used to remotely select several single-band antenna > tuners and several end-fed vertical wire antennas strung up into some > tall trees. The "tuners" would be link-coupled tapped parallel tank > ciruits, one tuner per band. > > There would be two relays needed per band, one to switch the 50 ohm > coax from the shack to the specific tuner and the other at the output > end of the tuner to select the particular wire. At the input ends of > the tuners the RF voltage would be around 200V @ 2 amps. At the output > ends of the tuners (depending on the feedpoint impedance) the RF > voltage could go into the 2kV range at very low currents. So basically > I need some sort of relays which can handle 2kV of HF RF at 2 amps. > Single pole NO non-latching reed switches would do the job. > > I know I can use surplus vacuum relays but at $35-40 a pop that ain't > gonna happen. > > Any and all suggestions will be appreciated. > > w3rv Brian Have you considered building your own coax relays? It is fairly easy to construct a SPST coax relay with glass enclosed tube shaped reed relays. Their performance may be acceptable to you, maybe not. But I have built my own coax relays from regular relays and have gotten adequate performance. Jerry Article: 217997 of rec.radio.amateur.antenna From: "Asimov" Subject: Vertical colinear Message-ID: References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Date: Sun, 02 Oct 2005 20:01:26 GMT "Dave VanHorn" bravely wrote to "All" (02 Oct 05 09:15:26) --- on the heady topic of "Vertical colinear" DV> From: "Dave VanHorn" DV> Xref: core-easynews rec.radio.amateur.antenna:217909 DV> I'm a bit confused over the construction of a vertical colinear. DV> The docs I've seen all are more or less the same, alternating DV> half-wave sections of coax or hardline. DV> The thing that's bending my head, is that there's a velocity factor DV> inside the coax, that presumably isn't there on the outside. DV> So, while a given section is a half wave on the outside, it's probably DV> more like 3/4 wave inside. DV> My understanding is that we are trying to get to a series of dipoles DV> all fed in phase, and yet this seems like it's not accomplishing that. DV> What am I missing? The wave energy travels alternately on the outside of the center conductor and then on the inside of the braid or shielding. So both see the same velocity factor. Does that make sense? A*s*i*m*o*v ... What if there were no hypothetical situations? Article: 217998 of rec.radio.amateur.antenna From: "Asimov" Subject: Re: Where to by random wire (longwire) antennas Message-ID: References: <1pivj1dpef92l4b61vlbqe03ravkj3dfbm@4ax.com> Date: Sun, 02 Oct 2005 20:01:28 GMT "Buther Boy" bravely wrote to "All" (02 Oct 05 06:59:32) --- on the heady topic of "Re: Where to by random wire (longwire) antennas" BB> From: Buther Boy BB> Xref: core-easynews rec.radio.amateur.antenna:217904 BB> Howard: BB> I somehow "dreamed" of being able to hide this random wire in my house BB> and tune it up, but that is looking more improbable by the minute. I BB> live in a town home and have no yard. Things don't look good, but I BB> have an excellent idea of how this all works. I appreciate your help, BB> Howard, and thanks for the detailed explanations. BB> Buther Boy You can hide wire in the oddest places. For example there is a 40 foot long clothesline outside in back of the house and it is made of steel. Someone a little bit crafty might replace that line with copperclad and nobody would be the wiser unless they looked a little closer. Hidden in plain sight! A*s*i*m*o*v ... "Please do not offer my god a peanut!" --Apu Article: 217999 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Need Suggestions for a Relay Source References: <1128269672.814425.42830@g14g2000cwa.googlegroups.com> Message-ID: Date: Sun, 02 Oct 2005 20:29:39 GMT Brian Kelly wrote: > I know I can use surplus vacuum relays but at $35-40 a pop that ain't > gonna happen. Hi Brian, the Omron LY series seem to handle 100w for me. Perhaps you can contact Omron about their limits. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218000 of rec.radio.amateur.antenna From: "Dave VanHorn" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Subject: Re: Vertical colinear Message-ID: Date: Sun, 2 Oct 2005 15:20:27 -0500 The wave energy travels alternately on the outside of the center conductor and then on the inside of the braid or shielding. So both see the same velocity factor. Does that make sense? Hmm.. So the first and second radiators are not in phase, but the first, third, fifth .... are in phase with each other, and the second, fourth, etc are in phase with each other? Article: 218001 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <2e4ae$43402795$97d558d8$23323@ALLTEL.NET> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Sun, 2 Oct 2005 16:22:51 -0400 Message-ID: <3353f$434041cf$97d558d8$17905@ALLTEL.NET> OK, since your one of us we will give you a little slack. I will even point out that the example you found had nothing to do with rules, but sent an idiot to a non-existant forum who daily posted far out anti Bush stuff. "Pat Stevens" wrote in message news:LqW%e.18322$Xl2.4448@twister.nyroc.rr.com... > No, I only spent a couple of minutes looking. I thought it was interesting > that the shoe is now on the other foot, for you. Found your page > interesting, too. > However, I find it ironic that you call me a yankee. I have been trying to > shed the southerner image here with my friends and coworkers ever since I > moved up here from Myrtle Beach, after retiring from the Air Force. I grew > up in Beaufort, SC, near the Naval Hospital. Most people say that I still > have the accent. > > "Fred W4JLE" wrote in message > news:2e4ae$43402795$97d558d8$23323@ALLTEL.NET... > > Did we cause you to spend two days googling newsgroups? You could have > > found > > much better examples, I have been getting after net nazis since the ARPA > > days. Your still a damnyankee liberal twit. > > > > > > "Pat Stevens" wrote in message > > news:FTT%e.17504$Xl2.16932@twister.nyroc.rr.com... > >> Hey, Fred, > >> Does this ring a bell? Why do you feel this group would be any different > >> than the one you posted the following message to? > >> > >> Re: Man, Mr. bush Jr. sure is wicked evil eh? > >> by "w4jle" Apr 22, 2004 at 07:13 PM > >> > >> > >> Take this crap to alt.wewearaluminimum.hats > >> > >> Any body forwarding this much crap either is being paid to do it, or > >> seriously needs to get a life! > >> > >> > >> -- > >> W4jle.com - Home of the Professional Curmudgeon > >> > >> > >> > >> > >> "Fred W4JLE" wrote in message > >> news:55b0c$433f44ba$97d558d8$25020@ALLTEL.NET... > >> > Do I look like I am "hiding" you twit! > >> > > >> > I can see not only are you too stupid to use a newsreader, in addition > > you > >> > have no clue as to what can be gleaned from my call. > >> > > >> > I love upsetting supercillious net Nazis. Makes my day. > >> > > >> > "Pat Stevens" wrote in message > >> > news:R7H%e.17307$Xl2.9545@twister.nyroc.rr.com... > >> >> Ok. So, you were the bully who couldn't follow rules and believe that > >> > they > >> >> never apply to you. So, now you are continuing that ideology in life > > as > >> > you > >> >> "hide behind your keyboard." > >> > > >> > > >> > >> > > > > > > Article: 218002 of rec.radio.amateur.antenna From: "Dave VanHorn" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Subject: Re: Vertical colinear Message-ID: Date: Sun, 2 Oct 2005 16:29:12 -0500 > I dont think you are missing anything. The feed points of each of the > radiating elements need to be in phase if 'broadside pattern max' is > desired. > > Do you intend to build an array, or just trying to understand them? Both. I have some FSJ1-50 that I got for the purpose. The docs that I've seen are all pretty consistent on how it should be put together, but I just don't understand the workings of it. IF the coax had a VF of 1.0, then it would make sense to me. Article: 218003 of rec.radio.amateur.antenna From: "Dave VanHorn" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Subject: Re: Vertical colinear Message-ID: Date: Sun, 2 Oct 2005 16:30:03 -0500 Do all the elements radiate? Article: 218004 of rec.radio.amateur.antenna From: "Jerry Martes" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> Subject: Re: Vertical colinear Message-ID: <33Z%e.4169$097.2908@trnddc01> Date: Sun, 02 Oct 2005 22:20:47 GMT "Dave VanHorn" wrote in message news:JiY%e.2044$AR2.1519@fe81.usenetserver.com... > >> I dont think you are missing anything. The feed points of each of the >> radiating elements need to be in phase if 'broadside pattern max' is >> desired. >> >> Do you intend to build an array, or just trying to understand them? > > > Both. I have some FSJ1-50 that I got for the purpose. > > The docs that I've seen are all pretty consistent on how it should be put > together, but I just don't understand the workings of it. > > IF the coax had a VF of 1.0, then it would make sense to me. Dave Have you looked at the collinear antenna on the web written by "Brian Oblivious"? He cuts the coax into equal lengths 1/2 wave each. And that 1/2 wavelength accounts for the velocity of propagation inside the coax. So, each length is somewhat shorter than the free space halfwave It shows how he connected lengths of coax to make a collinear array. In my opinion, that would be a waste of that good coax you have. I once manufactured a vertical collinear antenna that had only one feed point and the other collinear elements were passively connected when stacked below the "fed dipole". Sometimes it is convenient to mount vertical half wave dipoles around a vertical supporting mast and have a "corporate feed harness" within the mast. That works well. Article: 218005 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Emergency Messaging And AM Date: Sun, 2 Oct 2005 18:29:13 -0400 Message-ID: Crossposted to: rec.radio.amateur.antenna,rec.radio.amateur.misc,rec,radio.amateur.equipment Novitiate here: I am learning AM broadcast basics in particular the issues regarding the geo-targeted broadcasting of alert messages from moving vehicles. Would most appreciate any assistance. Due to Katrina/Rita, the company I work for has been given the opportunity to demonstrate a messaging system that would reach out approximately 1 mile +/- in transmission deliverance. This would be an "overbroadcast" (my term) in that it would override local AM radio broadcasting to reach into cars, trucks etc. In particular, we are working with a stationary site (a chemical spill for instance) and an emergency vehicle that would move back and forth at and through the site, at up to 70 mph, broadcasting an alert, voice and tone message. Reading about LPAM, this looks technically possible but one concern I have is antennae size. A fire truck, for instance, could have an antenna mounted on its front, and up to 4 feet over the top of its roof, so we might look at as much as 20 feet of length. I realize this places us over the 3 meter max so one of the ???? is whether LFAM is realistic. Am I way off base here, can any antennae, fractal or other, or any AM antennae technology, be utilized to design an antenna and propagate this type of signal? All comments appreciated. -- Drop the alphabet for email Article: 218006 of rec.radio.amateur.antenna From: "Dave VanHorn" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> <33Z%e.4169$097.2908@trnddc01> Subject: Re: Vertical colinear Message-ID: Date: Sun, 2 Oct 2005 17:34:24 -0500 > Have you looked at the collinear antenna on the web written by "Brian > Oblivious"? No, I googled on it but didn't hit anything. > He cuts the coax into equal lengths 1/2 wave each. The articles I have seen are 1/2 wave * the velocity factor. Each one connecting center to shield. I can't picture how the elements all end up resonant, and in phase. Seems like one of those can't be true. > And that > 1/2 wavelength accounts for the velocity of propagation inside the coax. > So, each length is somewhat shorter than the free space halfwave It shows > how he connected lengths of coax to make a collinear array. In my opinion, > that would be a waste of that good coax you have. Why? It's nice rigid coax, and takes that sort of soldering well. Article: 218007 of rec.radio.amateur.antenna From: "Jerry Martes" References: <2YR%e.2887$nJ2.2349@fe73.usenetserver.com> <33Z%e.4169$097.2908@trnddc01> Subject: Re: Vertical colinear Message-ID: Date: Sun, 02 Oct 2005 22:51:01 GMT "Dave VanHorn" wrote in message news:QfZ%e.12769$qj2.6857@fe71.usenetserver.com... >> Have you looked at the collinear antenna on the web written by "Brian > >> Oblivious"? > > No, I googled on it but didn't hit anything. > >> He cuts the coax into equal lengths 1/2 wave each. > > The articles I have seen are 1/2 wave * the velocity factor. > > Each one connecting center to shield. > > I can't picture how the elements all end up resonant, and in phase. > > Seems like one of those can't be true. > >> And that > >> 1/2 wavelength accounts for the velocity of propagation inside the coax. > >> So, each length is somewhat shorter than the free space halfwave It shows > >> how he connected lengths of coax to make a collinear array. In my >> opinion, > >> that would be a waste of that good coax you have. > > Why? It's nice rigid coax, and takes that sort of soldering well. Dave I didnt mean to imply that your good coax wouldnt work well. I (perhaps wrongly) assumed that some garden variety coax might work OK for that staggering of lengths of coax, inner conductor to outer conductor. My web service thru Google, gets me that Brian Oblivious + Capt Kaboom site on their 802.11 2.4 GHz antenna. They indicate that the "elements" are 1/2 wave long minus the Vp inside the coax. That will put the feed points along that 'staggered' array, in phase. You have probably already considered that there will be some beam squint with this type of collinear. The "corporate fed" collinear will a maintain a main beam broadside, even though sidelobes do increase with bandwidth. Jerry Article: 218008 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Small, non-resonant, horiz. loop. was Re: Magnetic Loop !!! Date: Sun, 2 Oct 2005 22:53:30 +0000 (UTC) Message-ID: References: <433D46F0.D0533E2B@shaw.ca> <433D7754.F019C9B2@shaw.ca> <11jrte940qbbf67@corp.supernews.com> <11jsujdpigc5dff@corp.supernews.com> <11jtdf05htl4j4a@corp.supernews.com> <11jub2qsovg9gae@corp.supernews.com> <11k05blgo2vgq65@corp.supernews.com> Dear Prof., I too am concerned about the abysmal and still falling standards of education in our schools and universities. Prof., I am very pleased to have met you. ---- Reg, G4FGQ Article: 218009 of rec.radio.amateur.antenna From: "Ken Taylor" References: Subject: Re: Emergency Messaging And AM Message-ID: Date: Mon, 3 Oct 2005 11:59:58 +1300 "Ari Silversteinn" wrote in message news:r7evtegkcjgt.kuwb55vmxpjg$.dlg@40tude.net... > Crossposted to: > > rec.radio.amateur.antenna,rec.radio.amateur.misc,rec,radio.amateur.equipment > > Novitiate here: > > I am learning AM broadcast basics in particular the issues regarding the > geo-targeted broadcasting of alert messages from moving vehicles. Would > most appreciate any assistance. > > Due to Katrina/Rita, the company I work for has been given the opportunity > to demonstrate a messaging system that would reach out approximately 1 > mile > +/- in transmission deliverance. This would be an "overbroadcast" (my > term) > in that it would override local AM radio broadcasting to reach into cars, > trucks etc. In particular, we are working with a stationary site (a > chemical spill for instance) and an emergency vehicle that would move back > and forth at and through the site, at up to 70 mph, broadcasting an alert, > voice and tone message. > > Reading about LPAM, this looks technically possible but one concern I have > is antennae size. A fire truck, for instance, could have an antenna > mounted > on its front, and up to 4 feet over the top of its roof, so we might look > at as much as 20 feet of length. I realize this places us over the 3 meter > max so one of the ???? is whether LFAM is realistic. > > Am I way off base here, can any antennae, fractal or other, or any AM > antennae technology, be utilized to design an antenna and propagate this > type of signal? > > All comments appreciated. > -- The things that pop into my mind are why AM rather than FM, which tends to be more local, and do you intend to 'over-broadcast' only the local channels (how many?) - I assume you intend to make the channel(s) selectable - or the entire band to ensure you get everyone? Assuming that there is a commercial AM broadcast station in the vicinity (what, 10 miles? 20 miles?) you are probably going to be flat out getting a mobile rig to ride over it. How do you intend to do this? Cheers. Ken Article: 218010 of rec.radio.amateur.antenna From: "Denton" Subject: using 450 ohm twin lead to feed 43 ft multiband groundmounted vertical Date: Sun, 2 Oct 2005 17:08:17 -0700 Message-ID: <11k0tjh6hr34l44@corp.supernews.com> I have been tinkering with a 43 ft ground mounted vertical with an extensive buried radial field. With a 4 to 1 voltage balun at the base, I have a good swr match particurlarly on 20 meters, and the antenna radiates and recieves comparabily with my 10 horizontal cage doublet fed with open wire ladderline. I recently replaced the coax that feeds the balun at the vertical's base with 450 ohm twin lead utilizing the same balun at the antennas feedpoint, and still get a decent signal report...again comparing to the big cage dipole. The twin lead is enclose within some left over grey plastic conduit if anything to keep it out of the weather and to keep it about 2 feet off of the ground, parallel to the ground.There is no evidence ot the plastic conduit detuning the twin lead. Tuning via either a link coupled transmatch or a dentron super tuner plus, utilizing its internal balun is broad smooth and no evidence of rfi in the shack with the exception of 30 meters. Wonder if anyone has tried this before and how did they like this feed arrangement. Thanks in advance, de Denton WB7TDG Article: 218011 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Emergency Messaging And AM References: Message-ID: <3lb613-l4c.ln1@p400bob.personal.cox.net> Date: Sun, 02 Oct 2005 19:46:56 -0500 Hi Ari I always wonder whether broadcast at the most common IF frequencies would be a viable alternative? (eg 455khz for AM) Legality issues aside of course... This would make frequency selection a little easier to engineer. You wouldnt have to divide your power budget into many operating frequencies as well. Problem is that you'd need a lot higher ERP especially since car mounted radios tend to be better shielded than portables. (You'll need to experiment some) Since part of your engineering exercise will be to determine what ERP you want from the system you are proposing, the size of the antenna only needs to be considered in line with the transmitter output power. Obviously there will be a useful compromise somewhere that is cost effective. You might for example want a 100 watt TX for each frequency with a fairly lossy/terminated and loaded antenna. Your first port of call will be to determine what the likely highest strength of an AM/FM broadcast signal you will need to override, add maybe 20dB to that and work out your needed ERP. You will find lots of texts about the inefficiencies of MF antennas mounted on motor vehicles so that will give you some numbers to work with. Remember that making the antenna wideband will also introduce substantial loss. Note that you cant design the system to always work as you'll have situations where the radio stations transmitting antenna is right next to then freeqy where the event occurred! Decide on some statistical coverage percentage thing etc etc... I worked for a concern in Sydney Australia that put in tunnel rebroadcast systems in the major underground roadworks in Sydney, Melbourne and Perth. Being in a tunnel of course there werent really any licensing issues. The system consisted of not only broadcast band (AM & FM) receivers but spot VHF/UHF FM receivers and transmitters for police, fire etc vehicles. Each broadcast frequency had its own transmitter. It was thought to be a better idea than using a wide band TX covering all frequencies. AM broadcast was coupled to a very long wire and the rest used a terminated leaky coax run. Cheers Bob W5/VK2YQA Ari Silversteinn wrote: > I am learning AM broadcast basics in particular the issues regarding the > geo-targeted broadcasting of alert messages from moving vehicles. Would > most appreciate any assistance. > Article: 218012 of rec.radio.amateur.antenna From: David Subject: Re: Help with Sleeve Dipole References: <11k04mh9vbli6d1@corp.supernews.com> Message-ID: Date: Mon, 03 Oct 2005 02:02:13 GMT I am still confused on this one. I see a 1/4 wave radiating element joined to another 1/4 wave radiating element that just happens to also act as a choke to reduce RF on the return braid of the RG174 coax. The point where they meet is supposed to look like the centre of a 1/2 wave dipole so the impedance must be around the 72 Ohms If the Sleeve is acting as a choke(Stub) then does it not need a second element as the return (ie is it not acting like a 1/4 length of coax where the tube is the outer braid and the RG174 cable running up the centre outer sheath is the dielectric and the outer braid of the RG174 becomes the inner conductor of the stub )? If this is correct then the electrical length of the sleeve must be modified by the presence of the RG174 coax outer sheath. The sleeve is sort of performing a dual function. As it is difficult to cut the tube once soldered in place, I will need to make heaps of these to get the length right. At least if I had a reasonable starting point it would minimize the number of iterations. The other issue is that I read about cutting lengths for elements and not that even an element in free space is trimmed down by about 3% to account for some "end effect" ? Would this also apply to my sleeve ? If so, then the length may be difficult to get right because if I make allowance for the end effect then the choking effect of the sleeve will not work as well. I do not want to reinvent the wheel here as these antennae are sold already being sold commercially and I am sure there are numerous people who have successfully made these. Therefore if I can learn from other people's mistakes and success, the starting point is much closer to the solution. I have a practical application but want to understand also. The requirement is that I have a small antenna that can be built into the end of a RF connector and plug directly onto a radio modem operating in the 915MHz band. The power is 1 Watt max. The design needs to be repeatable and not require trimming at every location (being portable I have no control over where the unit is located), as there is no decent ground plane, I need a unit that does not require radials or large ground plane. The low radiation angle and no requirement for large ground plane made the J-Pole look like a good contender but it was physically difficult to mount in this application. After looking around and opening up some commercial units, I noted many used the Choke Sleeve, 1/2 wave dipole antenna. This is why I am now wanting to understand how these work and have a good starting point for making them. The commercial units used molded construction that was difficult for me to emulate. I have started with RG174 Cable, 5/32 Brass tube all attached to SMA plug and used 1/4" nylon tubing as a radome. It goes together well and looks good but does not perform very well. Thanks for any further info. Dave VanHorn wrote: >>>With the tubing over a coaxial cable though it seems there is Vp related >>>to the dielectric formed between the sleeve and the outer sheath of the >>>coax cable but also the Metal has an Er value. > > > From what I understand, the RF will be traveling on the outside of the > sleeve, and won't "see" the internals at all. > So, the sleeve ends up as a 1/4 wavelength stub. > > Is the diameter of the tubing critical (will it impact adversely > >>>on SWR looking into this antenna). > > > It shouldn't be > > >>>The final point would be if I place some ferrite rings across the coax >>>below the sleeve, will this improve SWR ? > > > Not if the sleeve is doing it's job. > The sleeve's open end should look like a short at the operating frequency, > and keep RF off the feedline. > > > >>>Thanks >>> >>>Regards >>> >>>David >> >>David; >> >>That's why they call it the ART of antenna design. First you make the >>best mathematical calculations you can then you start cutting wire/tubing. >>Make your lengths slightly longer than the math says then prune the >>lengths until the antenna works the way you think it should. >> >>There are so many variables in antennas that this is the only practical >>way to make a new one. Once you find your optimal lengths you can make >>more to the same specs. However remember that just like in housing >>antenna's depend on three things: location, location, location and have to >>be custom adjusted for each site. >> >>Dave WD9BDZ > > > > Article: 218013 of rec.radio.amateur.antenna Date: Sun, 02 Oct 2005 21:28:05 -0500 From: Tom Ring Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <2e4ae$43402795$97d558d8$23323@ALLTEL.NET> Message-ID: <43409736$0$3760$39cecf19@news.twtelecom.net> Fred W4JLE wrote: > Did we cause you to spend two days googling newsgroups? You could have found > much better examples, I have been getting after net nazis since the ARPA > days. Your still a damnyankee liberal twit. Not everyone north of the moron line is a "llberal yankee twit", so shove it up your southern idiot ass. tom a northern nondemocrat K0TAR Article: 218014 of rec.radio.amateur.antenna From: David Subject: Re: Help with Sleeve Dipole References: <11k04mh9vbli6d1@corp.supernews.com> <1r51k1t8dsujf2k54gdhtivlc1h8gr3qjb@4ax.com> Message-ID: Date: Mon, 03 Oct 2005 03:14:52 GMT Richard, With regard to performance. Doing an A/B comparison between the commercial antenna and my version. The range achieved by the commercial antenna was approximately 4 times the range of my version. The range was determined by loss of using one end as a beacon and moving the test unit further away until it could no longer receive valid packets, then move in and out of range several times to confirm consistency. The same was done with my version. Before the test, I monitored the return port on the directional coupler on a Spectrum analyzer while seeping frequency from the sig. gen and noted the SWR on the commercial unit was lower than my version. (Though the measurement was not calibrated I could see the SWR was better but did not determine how much). Previously I designed a Microwave movement detector that operated at 1.2 GHz using Doppler principle. It used a microstrip tank circuit connected to a negative resistance oscillator. The design was published (RF Design magazine Dec 1986). Though there were many technical issues regarding the oscillator (how to adjust impedance in the base for optimal negative resistance looking into emitter, effect of moving the antenna, ground plane under the antenna etc etc), others were able to make the design just as per my prototype and it worked. They could then proceed to"play" with the design to change its performance. I really would have expected that a similar scenario would exist with antenna design (Someone has made one just like what I am wanting to make and is able to share with me the details on what they did that worked, then I would play with the design). I am grateful for the many responses I have received from my postings to this group and am confident there is much good information in what I have received but mixed with people's actual experience is a bunch of theoretical information that makes it hard to pick out what is useful. (ie. some of the information has conflicted and left me not understanding what is actually happening here). If someone has actually made these types of antennas and has some practical experience with them, that would be a fantastic starting point for me. (ie. Low power, UHF, portable). Richard Clark wrote: > On Mon, 03 Oct 2005 02:02:13 GMT, David wrote: > > >>If this is correct then the electrical length of the sleeve must be >>modified by the presence of the RG174 coax outer sheath. The sleeve is >>sort of performing a dual function. > > > Hi David, > > I think I pointed that out already. The effects of this jacket are > variable across many suggestions offered here over the years. > > >>As it is difficult to cut the tube once soldered in place, I will need >>to make heaps of these to get the length right. At least if I had a >>reasonable starting point it would minimize the number of iterations. > > > Ah yes, the pain of it all. I mentioned that too. You may as well > grit your teeth and set to it, there is no shortcut to this all. > > >>The other issue is that I read about cutting lengths for elements and >>not that even an element in free space is trimmed down by about 3% to >>account for some "end effect" ? Would this also apply to my sleeve ? If >>so, then the length may be difficult to get right because if I make >>allowance for the end effect then the choking effect of the sleeve will >>not work as well. > > > You might want to work this backwards. That is start off with a > successful choke section of the sleeve. Let that dictate what follows > because its isolation will mediate what I describe. If you have any > experience with what is called an Offset Center Fed Dipole, you would > find that it offers a closer match to 50 Ohms. You are using the > dipole as a variable match by finding the 50 Ohm portion along its > full length. This means that the portion above the sleeve's > attachment to the drive point may not be the classic length (and > certainly not accounted by the 3% of the "end effect" - not even > close). > > That is neither here nor there because at that point you will have > simultaneously achieved resonance, a match, and isolation; and yet by > no fixed formula pulled out of a hat, nor accredited by an institution > of higher learning. > > And, by the way, it isn't going to pull together in the first pass. I > hope you have a stack of tubing, so put on a happy face and get down > to it. > > >>This is why I am now wanting to understand how these work and have a >>good starting point for making them. The commercial units used molded >>construction that was difficult for me to emulate. I have started with >>RG174 Cable, 5/32 Brass tube all attached to SMA plug and used 1/4" >>nylon tubing as a radome. It goes together well and looks good but does >>not perform very well. > > > How do you know? It might be doing the best job you could ask of any > design. Your statement requires FAR MORE qualification than a rather > subjective toss-off. > > In other words: > 1. To what parameters? > 2. Compared to what? > 3. By what measure? > > 73's > Richard Clark, KB7QHC Article: 218015 of rec.radio.amateur.antenna From: "Crazy George" References: Subject: Re: Emergency Messaging And AM Date: Sun, 2 Oct 2005 22:26:11 -0500 Message-ID: <4340a8ca_3@news1.prserv.net> Well, Ari, I can tell you this. People used to mock the fact that I had 7 antennas on my 1957 station wagon almost 50 years ago, but these days, the airwaves are so bereft of anything worth listening to, I never turn on a radio in the car. So, I will never hear your message no matter what you try. Now, having said that, here is how the system design needs to be: Since the frequency to which a target radio is tuned is an unknown, and since the input contains a good trap for the IF frequency, your transmitter needs to radiate about 2 KW ERP at each of three frequencies in the broadcast band separated by 262 kHz and 455 kHz. This will mix in the front end and produce a useful IF. Same technique on FM using two frequencies 10.7 MHz apart. Good luck on the AM. With expected antenna efficiencies at that wavelength of about 3%, you are going to need over 100 kW of RF and antenna components with equivalent power ratings. Let us know how it works out. The place I used to work no bid this about 20 years ago due to these problems, and that was not the first time this crazy idea surfaced. -- Crazy George "Ari Silversteinn" wrote in message news:r7evtegkcjgt.kuwb55vmxpjg$.dlg@40tude.net... > Crossposted to: > > rec.radio.amateur.antenna,rec.radio.amateur.misc,rec,radio.amateur.equipment > > Novitiate here: > > I am learning AM broadcast basics in particular the issues regarding the > geo-targeted broadcasting of alert messages from moving vehicles. Would > most appreciate any assistance. > > Due to Katrina/Rita, the company I work for has been given the opportunity > to demonstrate a messaging system that would reach out approximately 1 mile > +/- in transmission deliverance. This would be an "overbroadcast" (my term) > in that it would override local AM radio broadcasting to reach into cars, > trucks etc. In particular, we are working with a stationary site (a > chemical spill for instance) and an emergency vehicle that would move back > and forth at and through the site, at up to 70 mph, broadcasting an alert, > voice and tone message. > > Reading about LPAM, this looks technically possible but one concern I have > is antennae size. A fire truck, for instance, could have an antenna mounted > on its front, and up to 4 feet over the top of its roof, so we might look > at as much as 20 feet of length. I realize this places us over the 3 meter > max so one of the ???? is whether LFAM is realistic. > > Am I way off base here, can any antennae, fractal or other, or any AM > antennae technology, be utilized to design an antenna and propagate this > type of signal? > > All comments appreciated. > -- > Drop the alphabet for email Article: 218016 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> Date: Mon, 03 Oct 2005 03:56:24 GMT On Thu, 29 Sep 2005 17:17:15 -0700, Richard Clark wrote: >On Thu, 29 Sep 2005 23:26:21 GMT, kashe@sonic.net wrote: > >> I'm not hearing any interest in turning streets near me into >>canals. > >In Santa Rosa? Perhaps if the Russian River overflowed - a lot. ISP location != subscriber location. One subscriber is in New Zealand. Article: 218017 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Miracle Whip Antenna Message-ID: References: <3v0pj1h66mvi1c2unrrhc43t9eadjcuthj@4ax.com> <2a91$433d5ccd$97d558d8$27561@ALLTEL.NET> Date: Mon, 03 Oct 2005 03:59:01 GMT On Fri, 30 Sep 2005 11:12:32 -0400, "Fred W4JLE" wrote: >1. Never eat at a place called Moms. >2. Never buy an antenna that has the word "Miracle" in the name or >description. Especially if it matches the name of a sandwich spread. Article: 218018 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Bad News for Hams? Message-ID: <36b1k1lvl1bqelr2pn7bfnbsuf03gakvdv@4ax.com> References: <88U_e.693$sL3.385@newssvr13.news.prodigy.com> <%yV_e.6858$q1.5550@newsread3.news.atl.earthlink.net> <433dd74e$0$32205$39cecf19@news.twtelecom.net> Date: Mon, 03 Oct 2005 04:04:59 GMT On Fri, 30 Sep 2005 19:24:45 -0500, Tom Ring wrote: >Bob Miller wrote: > >> >> It's not quite shortwave, but National Public Radio plays BBC >> programming from about midnight to 5 a.m. (at least my local station >> does) >> >> Bob >> k5qwg >> > >Great. Fine programming when no one can listen to it surrounded by tripe. Tripe is in the mind of the beholder. In tthis case, tripe is 100% of the mind content. I guess it's too complicated for him to hook up a VCR to a radio's audio out jacks. > >"I'll just go out back and shoot myself". Name the famous BBC Radio >Play that's from. I don't know, but it sounds like the poster who wouldn't look on the internet if he couldn't get BBC OTA. Pass the nose scalpel. > >tom >K0TAR Article: 218019 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Emergency Messaging And AM Date: Sun, 2 Oct 2005 23:02:15 -0500 Message-ID: <16583-4340AD47-680@storefull-3252.bay.webtv.net> References: Ari wrote: "--amessaging system that would reach out approximately 1 mile--." You don`t need a radio tire truck. You need a SOUND TRUCK with an AIR HORN to get the audience`s attention to listen to the message. Best regards, Richard Harrison, KB5WZI Article: 218020 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Help with Sleeve Dipole Date: Mon, 3 Oct 2005 00:32:08 -0500 Message-ID: <13319-4340C258-799@storefull-3255.bay.webtv.net> References: David wrote: "I am a little confused with calculation of appropriate length of metal tubing used in a sleeve antenna design (the 1/4 wave section)." It should approximate the free-space 1/4-wave valie. The coax exterior, or the cylinder exterior,,= is the radiator, so interior velocity factor is not involved. See the 3rd edition of Kraus` "Antennas", page 721 There are many other texts that may have better construction information, but everyone should have the Kraus book, or go get it now. "Transmission Lines, Antennas, and Wave Guides" by King, Mimno, and Wing is very good for sleeves as I recall, but I don`t have it at hand at the moment. The commercial and homemade versions I have used had (2) 1/4-wave secrions. The antenna was actually a center-fed vertical 1/2-wave dipole in which the coax was fed through the lower tubular section. The top section was just a rod or wire. These worked as well as ground plane =antennas, so we used them at VHF on small boats since there were no radials to get in the way or poke anyone in the eye. The cylinder is slightly shorter than the rod at a 1/4-wave resonant length. You can experiment to find the resonant lengths, then put them back to back to make your 1/2-wave dipole. Best regards, Richard Harrison, KB5WZI Article: 218021 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: <21l1k1hnpavq6i288c3tg759poutp5b4mk@4ax.com> References: <5ujsi196c3dl0l0a7su4uqltnt4u0ql4ko@4ax.com> <3f84j1t6o536tgnekhutv1ruepdo5d5ggs@4ax.com> Date: Mon, 03 Oct 2005 06:49:12 GMT On Fri, 30 Sep 2005 00:22:56 -0400, Uncle Ted wrote: >On Thu, 29 Sep 2005 23:56:14 GMT, kashe@sonic.net wrote: > > >> Mommy and Daddy have been dead since 95 and 61, respectively. >> >> If you think you're important enough that I should leap to the >>keyboard daily, you're sadly mistaken. I may only look in once a week. >>Live with it. >> >> So, you're not only full of shit on both counts, you're also >>wrong. >> >> And just how hollow is your life that you have to track my >>posting delays? Get a hobby. > >My, my! I seem to have hit a nerve. The only thing I've hit is a demonstration of the depths of your arrogance and stupidity. Article: 218022 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: <34l1k1h00rlsqgicd6fkg2fi4m490lv31g@4ax.com> References: <1127271443.195835.320110@g49g2000cwa.googlegroups.com> <43313df9$0$253$14726298@news.sunsite.dk> <4338A687.8D5B94DF@earthlink.net> <4338D057.B9B48493@earthlink.net> <8rvoj19bp6umuvfefeo6v87enpmg18pd8m@4ax.com> <84g%e.3872$KQ5.520@newssvr12.news.prodigy.com> Date: Mon, 03 Oct 2005 06:51:22 GMT On Fri, 30 Sep 2005 19:09:56 GMT, "Tom Donaly" wrote: >kashe@sonic.net wrote: >> On Thu, 29 Sep 2005 02:54:34 GMT, "Tom Donaly" >> wrote: >> >> >>>kashe@sonic.net wrote: >>> >>>>>Tom Donaly wrote: >>>>> >>>>> >>>>>>Faith and works are, like voltage and current, inextricably intertwined. >>>> >>>> >>>> They are not. >>>> >>>> >>>> >>>>>>The proof of faith is the good work. Those who do no good have no faith. >>>> >>>> >>>> Your logic book get lost in the hurricane? Come back when you >>>>can name the logical fallacy you just committed. >>> >>>Some of the lower forms of American Christianity try to separate faith >>>and works. That allows them salvation without substance, the lazy man's >>>path to life without end. >> >> >> in your narrow view. >> >> >>> My last two sentences are statements of truth >> >> >> "I fear the man who has all the answers." -- Father James >> Marien, S.J. -- 1961 -- in my presence. >> >> >>>, not a logical >>>progression. >> >> >> As written, they beg to be read as an incomplete syllogism. > >In other words, you made the connection up in your head. Typical. Jesus, another liunatic who thinks he knows all about me. Pompous bastard. > > >> >> >> >>>Each has to be taken alone, by itself. (A religious >>>fundamentalist insisting on logical consistency constitutes a >>>pretty good joke.) Let me repeat: Those who do no good have no >>>faith. >> >> >> Repitition does not include leaving off the first half of the >> line you wrote. In a humorous logic treatise, your statement would be >> named "The Proof from Blatant Assertion". >> >> >>>Next time you and your friends are sitting around speaking >>>in tongues, you should discuss this. Maybe, if you all think real >>>hard, together, you can puzzle out what it means. >> >> >> >>>73, >>>Tom Donaly, KA6RUH >> >> > >Unable to address the truth of what I wrote, you fantasize an argument >out of your sophomoric command of medieval logic. That, too, is typical, >if somewhat pathetic, since your religion is based on unquestioning >belief, superstition, and a fundamental opposition to science and >inquiring thought. Give it up. No brain can justify the brainless. Considering your lastname, I can take a stab at what your religin was before you lost it. >73, >Tom Donaly, KA6RUH Article: 218023 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: References: <5ujsi196c3dl0l0a7su4uqltnt4u0ql4ko@4ax.com> <3f84j1t6o536tgnekhutv1ruepdo5d5ggs@4ax.com> Date: Mon, 03 Oct 2005 06:53:32 GMT On Fri, 30 Sep 2005 00:22:56 -0400, Uncle Ted wrote: >On Thu, 29 Sep 2005 23:56:14 GMT, kashe@sonic.net wrote: > > >> Mommy and Daddy have been dead since 95 and 61, respectively. >> >> If you think you're important enough that I should leap to the >>keyboard daily, you're sadly mistaken. I may only look in once a week. >>Live with it. >> >> So, you're not only full of shit on both counts, you're also >>wrong. >> >> And just how hollow is your life that you have to track my >>posting delays? Get a hobby. > >My, my! I seem to have hit a nerve. You couldn't hit your ass with a sword stuck in a toilet. Article: 218024 of rec.radio.amateur.antenna From: "G L Carter" References: <16583-4340AD47-680@storefull-3252.bay.webtv.net> Subject: Re: Emergency Messaging And AM Message-ID: Date: Mon, 03 Oct 2005 08:22:17 GMT Amen to that Richard. I also question the wisdom of transmitting RF in a hazardous chemical spillage area. GeoffC "Richard Harrison" wrote in message news:16583-4340AD47-680@storefull-3252.bay.webtv.net... > Ari wrote: > "--amessaging system that would reach out approximately 1 mile--." > > You don`t need a radio tire truck. You need a SOUND TRUCK with an AIR > HORN to get the audience`s attention to listen to the message. > > Best regards, Richard Harrison, KB5WZI > Article: 218025 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Antenna for Danish Radio 1062 KHz Date: Mon, 3 Oct 2005 08:09:23 -0500 Message-ID: <13320-43412D83-252@storefull-3255.bay.webtv.net> References: <4337050e$1_1@news.estpak.ee> Sonnich Jenson wrote: "I`d like to listen to Danish Radio PS, on 1062 Medium wave." A loop antenna is a good start for better signal to noise in a fixed location. The 3rd edition of Kraus` "Antennas" says on page 217: "The radiation efficiency of a multiturn loop or coil antenna can be increased by introducing a ferrite rod into the coil as in Fig 7-18." My Telefunken Opus table radio has such a tuned horizontal ferrite loop stick to receive vertically polarized waves. Its azimuth is rotatable by a knob on the front panel for best reception. External loops are available from many sources for use with your radio. If one of these is wired to your antenna terminals, only the position of the external loop need e changed for best reception. For suppressing mobile noise, consult an expert such as A.A. Ghirardi. Automobiles now come with fair radio noise suppression, but may have defects. The car`s engine compartment should be a continuous conductive shell which traps noise within. All conductors penetrating this shell must be grounded or they must be bypassed to ground (the car body) with caopacitors. Your problem is weak signal and powerful noise. Good luck! Best regards, Richard Harrison, KB5WZI Article: 218026 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1jepj1p4qngh1ivp6bo4c1rc3vulugi6d5@4ax.com> <8bgpj11ofckhvd5dcg0umujbqav3508g9m@4ax.com> <0h0rj1ho78qtofjckgk0nrrqu4mgn8di5k@4ax.com> <2ym%e.16419$Xl2.3609@twister.nyroc.rr.com> <021sj1hb84shphia0dq78pl55r0q65sntl@4ax.com> <7d3a5$433e926c$97d558d8$32550@ALLTEL.NET> <8b50$433f1398$97d558d8$27686@ALLTEL.NET> <55b0c$433f44ba$97d558d8$25020@ALLTEL.NET> <2e4ae$43402795$97d558d8$23323@ALLTEL.NET> <43409736$0$3760$39cecf19@news.twtelecom.net> Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Mon, 3 Oct 2005 09:55:26 -0400 Message-ID: <915cb$43413882$97d558d8$23621@ALLTEL.NET> Having a reading comprehension problem Tom? Please point to the portion of the below sentence that says "ALL". The word "YOUR" is the operable one and has a distinct meaning. You Yankees are getting like the blacks, looking for any slight, real or imagined, so you may take umbrage with it... What exactly is the "it" that I am supposed to use as a suppository? Fred A Southern curmudgeon W4JLE "Tom Ring" wrote in message news:43409736$0$3760$39cecf19@news.twtelecom.net... > Fred W4JLE wrote: > > Did we cause you to spend two days googling newsgroups? You could have found > > much better examples, I have been getting after net nazis since the ARPA > > days. Your still a damnyankee liberal twit. > > Not everyone north of the moron line is a "llberal yankee twit", so > shove it up your southern idiot ass. > > tom > a northern nondemocrat > K0TAR Article: 218027 of rec.radio.amateur.antenna From: Bob Bob Subject: Balanced from unbalanced via a 100 ohm Q section - followup Message-ID: Date: Mon, 03 Oct 2005 09:25:47 -0500 Someone asked me how this antenna worked after I had built the Q section >from two pieces of 50r coax side by side, using the centre conductors as an open wire feeder equivalent. The shields being joined at each end but nowhere else.. (There should be grounded at the bottom end and at some neutral point at the top - if any) The antenna is a almost equilateral triangular shaped single quad loop with base/feed about 4 metres off the ground. The "almost" being the horizontal/top section is about 8 metres in length. Well it works! I dont have enough of a power supply at the moment for doing any extensive on air tests. VSWR was 1.4:1 without much excursion at the band edges. This is what 4NEC2 said it would be. In fact I didnt have to cut it after following the modelled dimensions. It was surprisingly wide band I guess from the higher feed Z (rather than using a single 75r section) I have only just moved here and there is a lot of noise about at various times of the day. (S7-9) I have heard stations across the US and maybe some Spanish speaking. Waiting for a PSU to arrive so I can try a little harder. I didnt notice any VSWR changes or a change in feedline radiation (through PC/stereo spkrs etc) by coiling the coax at the base of the Q section. Indeed I did it because I was at risk getting tangled in the coax going to the trash can! I expect high radiation angles BTW. Cheers Bob W5/VK2YQA East Texas. Article: 218028 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Colinear question References: Message-ID: Date: Mon, 03 Oct 2005 09:11:37 -0500 Yes! The "there and back" is often seen as phasing coils on mobile UHF verticals. Also the same kind of logic as a colinear J pole (for example) that has the hairpin shaped thing about half way up the radiating section of the antenna. You can also get colinear effects by using alternate halfwaves of very thick vs very thing elements (eg 25mm pipe and 2mm wire on 144MHz) but as one long "element" rather than bending it back and forth. (Yes the gain is lower for a given length) Keep in mind that it is prudent to feed in the middle of the antenna, probably at one of the hairpins sections. Its a good place as somewhere along the phasing section the Z will be that of your feedline. If you feed at the end the pattern tends to skew away from the feedpoint. Cheers Bob VK2YQA Jim Richardson wrote: ... > > something like this. > > Feed> __||__||__||__ Article: 218029 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:23:39 -0400 Message-ID: <1h0p718coajoy.1e5zi3aftiw8r.dlg@40tude.net> References: On Mon, 3 Oct 2005 11:59:58 +1300, Ken Taylor wrote: >> Am I way off base here, can any antennae, fractal or other, or any AM >> antennae technology, be utilized to design an antenna and propagate this >> type of signal? >> >> All comments appreciated. >> -- > The things that pop into my mind are why AM rather than FM, which tends to > be more local, and do you intend to 'over-broadcast' only the local channels > (how many?) - I assume you intend to make the channel(s) selectable - or the > entire band to ensure you get everyone? The issue of selective vs full range broadcasting is a matter that has not been decided either by client, company or possibility. There are plusses and minus' to each. Selective would entail less power but we are being told power of the fire engine is not an issue. > Assuming that there is a commercial > AM broadcast station in the vicinity (what, 10 miles? 20 miles?) you are > probably going to be flat out getting a mobile rig to ride over it. How do > you intend to do this? > > Cheers. > > Ken lol Good question, Ken. Any suggestions? -- Drop the alphabet for email Article: 218030 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:28:32 -0400 Message-ID: <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> References: <434071D1.1080009@nettally.com> On Sun, 02 Oct 2005 23:42:16 GMT, **THE-RFI-EMI-GUY** wrote: > A disadvantage I see is that a waiver is going to be required in order > not to violate FCC rules. In fact, in the state of Florida, interfering > with broadcast stations is against state law, so another hurdle to be > overcome. Yes, the budget is rich with expected legal expenses. Since DHS has become a player in this, we are hopeful that we can get the necessary punch to overcome FCC and statutory issues. >That being said, for this system to work, you have to blanket > the entire AM and FM broadcast bands. Even doing so will leave out the > motorists who use XM or Sirius, the Ipod listeners and those who are > driving with their cellphones plugged into their ears. Do we have to blanket or only blanket each locale, that is, the broadcasting stations of each locale? Not only will we miss those no AM/FM listeners, we will miss those that don't have their radios on. An aggressive, road sign campaign is planned something like " Turn On Your Radio, It Could Save Your Life" type of thing near each incident site. -- Drop the alphabet for email Article: 218031 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup Date: Mon, 3 Oct 2005 15:42:17 +0000 (UTC) Message-ID: References: "Bob Bob" wrote in message news:ckr713-tfd.ln1@p400bob.personal.cox.net... > Someone asked me how this antenna worked after I had built the Q section > from two pieces of 50r coax side by side, using the centre conductors as > an open wire feeder equivalent. The shields being joined at each end but > nowhere else.. (There should be grounded at the bottom end and at some > neutral point at the top - if any) > > The antenna is a almost equilateral triangular shaped single quad loop > with base/feed about 4 metres off the ground. The "almost" being the > horizontal/top section is about 8 metres in length. > > Well it works! I dont have enough of a power supply at the moment for > doing any extensive on air tests. VSWR was 1.4:1 without much excursion > at the band edges. This is what 4NEC2 said it would be. In fact I didnt > have to cut it after following the modelled dimensions. It was > surprisingly wide band I guess from the higher feed Z (rather than using > a single 75r section) > > I have only just moved here and there is a lot of noise about at various > times of the day. (S7-9) I have heard stations across the US and maybe > some Spanish speaking. Waiting for a PSU to arrive so I can try a little > harder. > > I didnt notice any VSWR changes or a change in feedline radiation > (through PC/stereo spkrs etc) by coiling the coax at the base of the Q > section. Indeed I did it because I was at risk getting tangled in the > coax going to the trash can! > > I expect high radiation angles BTW. > > Cheers Bob W5/VK2YQA East Texas. =============================== Bob, what is the purpose of the coaxial outer conductors which are not connected to anything.except to each other? ---- Reg. Article: 218032 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:45:29 -0400 Message-ID: References: <3lb613-l4c.ln1@p400bob.personal.cox.net> On Sun, 02 Oct 2005 19:46:56 -0500, Bob Bob wrote: > Hi Ari Thanks for comments, Bob. > I always wonder whether broadcast at the most common IF frequencies > would be a viable alternative? (eg 455khz for AM) Legality issues aside > of course... I'm missing your point. Please explain. > This would make frequency selection a little easier to > engineer. You wouldnt have to divide your power budget into many > operating frequencies as well. Problem is that you'd need a lot higher > ERP especially since car mounted radios tend to be better shielded than > portables. (You'll need to experiment some) Agreed. > Since part of your engineering exercise will be to determine what ERP > you want from the system you are proposing, the size of the antenna only > needs to be considered in line with the transmitter output power. > Obviously there will be a useful compromise somewhere that is cost > effective. You might for example want a 100 watt TX for each frequency > with a fairly lossy/terminated and loaded antenna. Your first port of > call will be to determine what the likely highest strength of an AM/FM > broadcast signal you will need to override, add maybe 20dB to that and > work out your needed ERP. Good advice here, will 20db do it? > You will find lots of texts about the > inefficiencies of MF antennas mounted on motor vehicles so that will > give you some numbers to work with. Remember that making the antenna > wideband will also introduce substantial loss. Note that you cant design > the system to always work as you'll have situations where the radio > stations transmitting antenna is right next to then freeqy where the > event occurred! Decide on some statistical coverage percentage thing etc > etc... Yes, we are shooting for max overbroadcasting but the reality is it is a hit and miss proposition. Even the scenario of geo related obstructions is a possibility. > I worked for a concern in Sydney Australia that put in tunnel > rebroadcast systems in the major underground roadworks in Sydney, > Melbourne and Perth. Being in a tunnel of course there werent really any > licensing issues. Is that peculiar to Aus? > The system consisted of not only broadcast band (AM & > FM) receivers but spot VHF/UHF FM receivers and transmitters for police, > fire etc vehicles. Each broadcast frequency had its own transmitter. It > was thought to be a better idea than using a wide band TX covering all > frequencies. AM broadcast was coupled to a very long wire and the rest > used a terminated leaky coax run. > > Cheers Bob W5/VK2YQA Very nice, congrats on that. Was it Yagi technology or fractal? -- Drop the alphabet for email Article: 218033 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:46:16 -0400 Message-ID: <1nx6q2oe5hqcd.16luh3kexsz0p$.dlg@40tude.net> References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128303416.672602.69070@g47g2000cwa.googlegroups.com> On 2 Oct 2005 18:36:56 -0700, hhc314@yahoo.com wrote: > I agree Bob. "Tunnel Radio" systems have been around for over 20 > years, and AFAIK all broadcast on dual IF frequencies covering both am > and fm car radios. Here in Boston this type of system is in use in all > our tunnels. > > Harry C. Harry, is this a "pickup" system for lost signal? -- Drop the alphabet for email Article: 218034 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:52:49 -0400 Message-ID: <1fybqs5xy9vj4$.1qc8f33ae8wvw$.dlg@40tude.net> References: On Sun, 02 Oct 2005 20:49:50 -0400, J. Teske wrote: >>Due to Katrina/Rita, the company I work for has been given the opportunity >>to demonstrate a messaging system that would reach out approximately 1 mile >>+/- in transmission deliverance. This would be an "overbroadcast" (my term) >>in that it would override local AM radio broadcasting to reach into cars, >>trucks etc. In particular, we are working with a stationary site (a >>chemical spill for instance) and an emergency vehicle that would move back >>and forth at and through the site, at up to 70 mph, broadcasting an alert, >>voice and tone message. > > And what makes you think anyone is going to be listening on AM. I > think the vast majority of radio listenings in urban areas listen to > FM except possibly for drive time shows, 24 hour news stations and the > comparatively few people enamored of talk or religious radio. FM of > course is subject to the capture effect wherein the strongest signal > prevails to the exclusion of others (at least that is the theory). > > AM, particularly at night is subject to strong skywaves. We are making no preference as to AM or FM as in that we will be attempting to overbroadcast on each. The AM skywave issue is exactly that but the system need not be perfect, only as perfect as possible. >>Reading about LPAM, this looks technically possible but one concern I have >>is antennae size. A fire truck, for instance, could have an antenna mounted >>on its front, and up to 4 feet over the top of its roof, so we might look >>at as much as 20 feet of length. I realize this places us over the 3 meter >>max so one of the ???? is whether LFAM is realistic. The 3 meter limitation is clearly is a problem here, we haven't modeled a 3 meter yet. I also wonder what, if anything, LFAM gets us in terms of FCC approvals and state regulations. >>Am I way off base here, can any antennae, fractal or other, or any AM >>antennae technology, be utilized to design an antenna and propagate this >>type of signal? > > I think the problem here is not the technology, but a fundamental > misconception of what it is you are trying to prove and who is likely > to be your audience. At this point you do not need an engineer, you > need a sociologist. > > W3JT A sociologist? -- Drop the alphabet for email Article: 218035 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:56:25 -0400 Message-ID: <2aggpl1hjwc1.1eu407rcntj8g.dlg@40tude.net> References: <4340a8ca_3@news1.prserv.net> On Sun, 2 Oct 2005 22:26:11 -0500, Crazy George wrote: > Well, Ari, I can tell you this. People used to mock the fact that I had 7 > antennas on my 1957 station wagon almost 50 years ago, but these days, the > airwaves are so bereft of anything worth listening to, I never turn on a > radio in the car. So, I will never hear your message no matter what you > try. Not even in an obvious disaster situation? > Now, having said that, here is how the system design needs to be: > Since the frequency to which a target radio is tuned is an unknown, and > since the input contains a good trap for the IF frequency, your transmitter > needs to radiate about 2 KW ERP at each of three frequencies in the > broadcast band separated by 262 kHz and 455 kHz. This will mix in the front > end and produce a useful IF. Same technique on FM using two frequencies > 10.7 MHz apart. Got it, thanks for the specs. > Good luck on the AM. With expected antenna efficiencies at that wavelength > of about 3%, you are going to need over 100 kW of RF and antenna components > with equivalent power ratings. Yep, at least, maybe more but power availability off the emergency vehicle is supposed to be a non-issue, we will see. > Let us know how it works out. The place I used to work no bid this about 20 > years ago due to these problems, and that was not the first time this crazy > idea surfaced. Do you think it is crazy from the standpoint of legal or technical. The system itself would appear to be much needed. -- Drop the alphabet for email Article: 218036 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: 73 Ohms, How do you get it? Date: Mon, 3 Oct 2005 15:57:32 +0000 (UTC) Message-ID: References: <11736-433D59A7-93@storefull-3253.bay.webtv.net> "Richard Harrison" wrote in message news:11736-433D59A7-93@storefull-3253.bay.webtv.net... > Reg, G4FGQ wrote: > "When the circumference of the antenna rod is one wavelength, Zo = 0." > > Bailey adrees with Reg. I was remiss in not quoting Bailey`s caveat. The > formula does not hold for circumferences greater than one-quarter > wavelength. > > Bailey notes that uniform cross section conductors don`t have ubiform > impedances throughout their lengths. Zo is inversely proportional to > capacitance per unit length. Zo is lower at the antenna feedpoint than > at its conductors` middles. At the tips or open ends of antennas, Zo is > low. This is explained by the concentration of electric force lines at > the open end. > > Variation of Zo along an antenna need not deter one from finding a > workable average of surge impedance. Bailey has determined this to be: > > 276 log 1/P, where P=circumference of the conductor in wavelength, for > circumferences of less than 1/4-wavelength. > > For practical lengths of center-fed dipoles, the feedpoint impedance is > determined by combination of incident and reflected waves. Bailey has > worked out these for resonant lengths between 1/2 and 5 wavelengths. I > posted these long ago. But, for infinite length, Zo must prevail, as no > reflection will ever return. > > Best regards, Richard Harrison, KB5WZI > ===================================== Bailey, who I assume is a product of our universities, made a wild guess and then worked backwards towards a sensible question. ;o) ---- Reg. Article: 218037 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:57:50 -0400 Message-ID: <17tegkmvjr1j9.3a5f8ahg3ekq$.dlg@40tude.net> References: <16583-4340AD47-680@storefull-3252.bay.webtv.net> On Sun, 2 Oct 2005 23:02:15 -0500, Richard Harrison wrote: > Ari wrote: > "--amessaging system that would reach out approximately 1 mile--." > > You don`t need a radio tire truck. You need a SOUND TRUCK with an AIR > HORN to get the audience`s attention to listen to the message. > > Best regards, Richard Harrison, KB5WZI I have seen these systems and they have failed to do two things. Be heard in a modern car with loud radio and great insulation and 2) pass the populace acceptance test. -- Drop the alphabet for email Article: 218038 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 11:58:35 -0400 Message-ID: References: <16583-4340AD47-680@storefull-3252.bay.webtv.net> On Mon, 03 Oct 2005 08:22:17 GMT, G L Carter wrote: > Amen to that Richard. > I also question the wisdom of transmitting RF in a hazardous chemical > spillage area. > > GeoffC That is not on our side of the table though. How this sytem is ultimately used is out of our hands. -- Drop the alphabet for email Article: 218039 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 12:01:14 -0400 Message-ID: <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> In that case, simply modify the sign to "Tune to 560, it could save your life" and use a discrete frequency low power transmitter. "Ari Silversteinn" wrote in message news:1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net... > On Sun, 02 Oct 2005 23:42:16 GMT, **THE-RFI-EMI-GUY** wrote: > > Not only will we miss those no AM/FM listeners, we will miss those that > don't have their radios on. An aggressive, road sign campaign is planned > something like " Turn On Your Radio, It Could Save Your Life" type of thing > near each incident site. Article: 218040 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Colinear question Date: Mon, 3 Oct 2005 11:09:41 -0500 Message-ID: <11735-434157C5-932@storefull-3253.bay.webtv.net> References: Jim Richardson wrote: "Could you build a colinear of a single long line bending it back at 90 deg. every half wave---?" See the "Super J" in the "ARRL Antenna Book", page 16-25 in my 19th edition. That is more or less how it is made. The two 1/2-waves, in-phase, are end-driven with phase inversion provided by a short-circuited 1/4-wave stub between them. At frequencies higher than 2-meters, this would work for more than (2) 1/2-wave sections. The practical limitation is mechanical. Best regards, Richard Harrison, KB5WZI Article: 218041 of rec.radio.amateur.antenna From: Steven Fritts Subject: EXP 14 Hygain Antenna question Message-ID: Date: Mon, 03 Oct 2005 12:39:01 -0400 Does anyone have any experience wirth this antenna? I need pros or cons on it as I may be purchasing one soon. Thanks Steve W4SEF Article: 218042 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: The CFA antenna is still with us Date: Mon, 3 Oct 2005 16:55:12 +0000 (UTC) Message-ID: I see from an Australian newsgroup that somebody is seriously considering and making plans to cover the whole continent using a pair of longwave, 1-megawatt, broadcast transmitters. The antennas are to be Professor Hately's CFA's which perform according to Maxwell's 4th Equation. Should somebody break the bad news to them before its too late? Or should we wait and have a good laugh? ---- Reg. Article: 218043 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Emergency Messaging And AM References: <3lb613-l4c.ln1@p400bob.personal.cox.net> Message-ID: Date: Mon, 03 Oct 2005 11:50:35 -0500 Hi Ari >>I always wonder whether broadcast at the most common IF frequencies >>would be a viable alternative? (eg 455khz for AM) Legality issues aside >>of course... > > > I'm missing your point. Please explain. I apologise if you already know the following! Its pretty basic radio.. Almost every radio receiver on the market works off the "superhetrodyne" principal where the incoming signal is mixed with a local oscillator down to an intermediate frequency. This makes receiver design a little cheaper as you can then put your expensive filtering at one frequency rather than have something that has to track the actual transmitted frequency. For example a station on the AM band at 870khz is mixed with a local oscillator of 1325 khz (in the receiver) to get a difference of 455khz. If the station frequency is changed then one only needs to modify the local oscillator frequency. This is what the knob on the radio does! The most common IF frequency for an AM radio happens to be 455khz so transmitting on that will mean you will be heard on all AM radios in close proximity. I dont off hand know the most common broadcast FM IF (maybe 10.7MHz or 7.8Mhz) but that should be easy to find. It is important to make sure that the IF of the fire trucks FM two-way radio isnt the same or you'll never be able to hear it inside the truck! To "broadcast over" you would need to amplitude modulate the AM band 455khz TX and frequency modulate the FM broadcast IF frequency. > Good advice here, will 20db do it? FM is easier to do than AM. I'd factor in maybe 6dB for FM. You might be able to get by with 12dB for AM but the original station will make some small amount of noise under it. The important thing is that the person listening wil be able to understand the content. Note that this is of course only relevent when transmitting on the actual station frequency. > Yes, we are shooting for max overbroadcasting but the reality is it is a > hit and miss proposition. Even the scenario of geo related obstructions is > a possibility. Well it shouldnt be that hard to model. Do a AM and FM band coverage prediction over the freeways etc you are doing the experiment on to discover what the receive strength will be in dBm. (It doesnt matter what "gain" you make the RX antenna because it will be the same figure that is used for your overbroadcast) For every say 200 yard square take the mean signal of each, then take the 80th percentile as the signal you have to beat. If that was (say) -80dBm you want -74dBm (for FM) at the maximum operating distance (was it a mile each way?) You then reverse model that to determine what the TX EIRP of the thing on the truck has to be. There are bound to be contract houses that will do this prediction for you. I use to work for one that had the software and I have some GPL versions myself. I cant do MF (ie AM broadcast) though. > Being in a tunnel of course there werent really any >>licensing issues. > Is that peculiar to Aus? The licensing issue or the tunnel? Tunnel rebroadcast is pretty common around the world. The company I worked for also did one in Indonesia. Its also used in underground mines. > Very nice, congrats on that. Was it Yagi technology or fractal? Err, the leaky coax was just a 2km run of an Andrews product that has leaky holes in the shield. It was fed in the middle with a wide band splitter and terminated with 50 ohmss at each end. Its quite a common thing to do in underground environments. (Buildings too) Handy for two way radio as well as cell phones. The AM thing was just a very long terminated (600r) wire. None of the above are yagi or fractal Cheers Bob Ari Silversteinn wrote: > Article: 218044 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup References: Message-ID: Date: Mon, 03 Oct 2005 11:18:05 -0500 Hi Reg The two pieces of coax are only meant to be a 100 ohm balanced Q section to translate the antenna Z to close to that of the main feedline (50r). I could do the same if I had some 100r open/ribbon feedline. The outer conductors/shield should be at zero potential and as such preserve the Z between the two inner conductors. This is handy in that the coaxes dont have to be bound close together and could be fed through a non metallic conduit without problems. Have I made any sense? Cheers Bob Reg Edwards wrote: > =============================== > > Bob, what is the purpose of the coaxial outer conductors which are not > connected to anything.except to each other? > ---- > Reg. > > Article: 218045 of rec.radio.amateur.antenna From: "Fred W4JLE" References: Subject: Re: EXP 14 Hygain Antenna question Date: Mon, 3 Oct 2005 13:11:43 -0400 Message-ID: Go to EHam.com and check the reviews. "Steven Fritts" wrote in message news:min2k1hehg7flr81l9pluefedfjujsfomd@4ax.com... > Does anyone have any experience wirth this antenna? I need pros or > cons on it as I may be purchasing one soon. > > Thanks > > Steve W4SEF Article: 218046 of rec.radio.amateur.antenna From: "Fred W4JLE" References: Subject: Re: EXP 14 Hygain Antenna question Date: Mon, 3 Oct 2005 13:39:19 -0400 Message-ID: <29e9c$43416cfb$97d558d8$11616@ALLTEL.NET> Whoops! That should have been Eham.net "Fred W4JLE" wrote in message news:e17c7$43416683$97d558d8$7114@ALLTEL.NET... > Go to EHam.com and check the reviews. > > "Steven Fritts" wrote in message > news:min2k1hehg7flr81l9pluefedfjujsfomd@4ax.com... > > Does anyone have any experience wirth this antenna? I need pros or > > cons on it as I may be purchasing one soon. > > > > Thanks > > > > Steve W4SEF > > Article: 218047 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Tables of Er for various metal tubes ? Date: Mon, 3 Oct 2005 18:06:59 +0000 (UTC) Message-ID: References: <0xL%e.4865$U51.3234@news-server.bigpond.net.au> "David" wrote in message news:A1R%e.5171$U51.541@news-server.bigpond.net.au... > OK, so the electrical wavelength of the tube will only be effected by > the dielectric material and it does not make any difference how large > the gap is between the Sleeve and the Coax ? > > The frequency of operation is 920 MHz. > > Do you happen to know what the covering is made of on the outer sheath > of RG174 ? ======================================= The jacket of coaxial cable is usually a soft grade of poly-vynil-chloride, PVC, which can have a dielectric constant anywhere between 4 and 6. The velocity factor along the outside of the coaxial braid depends on the thickness of the jacket. To make much difference to the VF it has to be an inch thick or more whereas it is probably only about 0.6mm. I will have a guess and say the VF is about 0.95. You can forget about it. ---- Reg. Article: 218048 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Need Suggestions for a Relay Source References: <1128269672.814425.42830@g14g2000cwa.googlegroups.com> <1128363545.419624.225460@g14g2000cwa.googlegroups.com> Message-ID: Date: Mon, 03 Oct 2005 18:29:10 GMT Brian Kelly wrote: > OhYeah, that's what I've been looking for. Tnx Cecil! I Googled 'em and > landed on the Mouser web page which lists the Omron LYs. They're good > for 10-15 amps @ 2 kV AC and for only $6-7 each. Should work fine > although I'd like to have higher voltage ratings. Not much to lose by > trying a couple of them to find out if they arc in the 110% humidity we > occasionally get around here. The LYs are designed to minimize humidity problems. The air gap is replaced by some sort of plastic separator. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218049 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: UWB pulse signal has no DC? Why? Date: Mon, 03 Oct 2005 11:24:25 -0700 Message-ID: References: <1127857483.866370.308610@z14g2000cwz.googlegroups.com> <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> Cecil Moore wrote: > Steady-state DC is incapable of generating coherent photons from an > antenna. At last a truism, arguably. ;-) ac6xg Article: 218050 of rec.radio.amateur.antenna From: Uncle Ted Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Mon, 03 Oct 2005 14:28:02 -0400 Message-ID: <90u2k11tr23up7rc7nfcgjufergc2efe62@4ax.com> References: <3f84j1t6o536tgnekhutv1ruepdo5d5ggs@4ax.com> On Mon, 03 Oct 2005 06:53:32 GMT, kashe@sonic.net wrote: >>> And just how hollow is your life that you have to track my >>>posting delays? Get a hobby. >> >>My, my! I seem to have hit a nerve. > > You couldn't hit your ass with a sword stuck in a toilet. Isn't it past your bedtime? Article: 218051 of rec.radio.amateur.antenna From: Uncle Ted Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Mon, 03 Oct 2005 14:30:55 -0400 Message-ID: References: <1127271443.195835.320110@g49g2000cwa.googlegroups.com> <43313df9$0$253$14726298@news.sunsite.dk> <4338A687.8D5B94DF@earthlink.net> <4338D057.B9B48493@earthlink.net> <8rvoj19bp6umuvfefeo6v87enpmg18pd8m@4ax.com> <84g%e.3872$KQ5.520@newssvr12.news.prodigy.com> <34l1k1h00rlsqgicd6fkg2fi4m490lv31g@4ax.com> On Mon, 03 Oct 2005 06:51:22 GMT, kashe@sonic.net wrote: >>> As written, they beg to be read as an incomplete syllogism. >> >>In other words, you made the connection up in your head. Typical. > > Jesus, another liunatic who thinks he knows all about me. >Pompous bastard. Mr. Pot, meet Mr. Kettle... Article: 218052 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: UWB pulse signal has no DC? Why? References: <1127857483.866370.308610@z14g2000cwz.googlegroups.com> <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> Message-ID: Date: Mon, 03 Oct 2005 18:49:51 GMT Jim Kelley wrote: > Cecil Moore wrote: >> Steady-state DC is incapable of generating coherent photons from an >> antenna. > > At last a truism, arguably. ;-) Say Jim, what is the frequency of virtual photons? -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218053 of rec.radio.amateur.antenna From: Jim Richardson Subject: Re: Colinear question Date: Mon, 3 Oct 2005 12:08:05 -0700 Message-ID: References: <11735-434157C5-932@storefull-3253.bay.webtv.net> On Mon, 3 Oct 2005 11:09:41 -0500, Richard Harrison wrote: > Jim Richardson wrote: > "Could you build a colinear of a single long line bending it back at 90 > deg. every half wave---?" > > See the "Super J" in the "ARRL Antenna Book", page 16-25 in my 19th > edition. That is more or less how it is made. The two 1/2-waves, > in-phase, are end-driven with phase inversion provided by a > short-circuited 1/4-wave stub between them. > I just picked up the ARRL book, it's a daunting tome... but interesting reading. > At frequencies higher than 2-meters, this would work for more than (2) > 1/2-wave sections. The practical limitation is mechanical. Makes sense, thanks. > > Best regards, Richard Harrison, KB5WZI > One of these days, hopefully in the near future, I'll get off my ass and take the ham test. Time.. always about time. -- Jim Richardson http://www.eskimo.com/~warlock Unix has security which has been tested by conniving, unscrupulous college students over generations. Article: 218054 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: The CFA antenna is still with us References: Message-ID: Date: Mon, 03 Oct 2005 13:49:56 -0500 Well if you must know, CFA stands for "Country Fire Authority", the (old name) volunteer firefighters in the state of Victoria... You confused yet? Bob VK2YQA (in W5) pfriedmanNoSpam wrote: > Neither. We should sell them the New & Improved version which performs > according to Beethoven's 5th. Or maybe a 5th of a good Highland malt? > > Paul AB0SI > > Article: 218055 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 15:54:56 -0400 Message-ID: References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> On Mon, 3 Oct 2005 12:01:14 -0400, Fred W4JLE wrote: > In that case, simply modify the sign to "Tune to 560, it could save your > life" and use a discrete frequency low power transmitter. I assume you mean to take up an unused local channel? Or to bargain for time on a used one? Both ideas make sense. -- Drop the alphabet for email Article: 218056 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 15:59:57 -0400 Message-ID: References: <1h0p718coajoy.1e5zi3aftiw8r.dlg@40tude.net> On Mon, 3 Oct 2005 16:20:40 -0000, Dave wrote: > there is no requirement that anyone listen to any broadcast radio. with the > rapid growth of satellite radio there are even less people listening to > either am of fm broadcast radio. add those who listen to cd's or dvd's and > you get even less. The loss of listenership is not arguable. > There are systems that are used for local road emergency notification, the > 560khz one comes to mind, something along those lines would be the best bet, > and add in signs on the backs of vehicles. i guess the real question is, > what are you trying to do by overriding local broadcast stations? 1) to grab those that are listening to AM/FM, it is still a hyooge market, 2) client request, 3) DHS preference 4) the number of people alerted by a sign/sticker and independent warning channel is much less than both that and AM/FM, 5) the possibility that once the AM/FM FCC/NAB bond is broken, a precedent could be set for cell, sat, threading messaging, etc 6) spinoff tech for local/reg/national emergencies. > and over > what size area? 1 mile radius max from point of incident, less most probably. -- Drop the alphabet for email Article: 218057 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:12:16 -0400 Message-ID: References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> >>Do we have to blanket or only blanket each locale, that is, the >>broadcasting stations of each locale? >> >>Not only will we miss those no AM/FM listeners, we will miss those that >>don't have their radios on. An aggressive, road sign campaign is planned >>something like " Turn On Your Radio, It Could Save Your Life" type of thing >>near each incident site. On Mon, 03 Oct 2005 12:58:40 -0400, J. Teske wrote: > While Florida may have laws to this effect, in fact they are > unenforcable because of federal preemption for all radio matters. > Still illegal, just the wrong enforcement entity. A state or locality > cannot for example legislate on TVI matters (though many have tried.) > When they try, the FCC will send a notice to the locals that they are > in charge and will handle enforcement. Unfortunately the FCC is > unwilling to get involved in the matter of private contracts such as > antenna exclusions in housing developments. Is there a reason that the locals try to overwrite Fed law then? > That said, be aware that when it comes to radio useage in the US, the > FCC is actually NOT the ultimate authority. They are responsible only > for those frequencies which a military controlled panel has ceded to > the FCC for administrative purposes. I can't remember the name right > off hand, but during my federal career, I had to work with them and we > actually were able to override an FCC allocation because it interfered > with a military application. While the FCC played ball with the DOD > outfit I worked for, the ultimate beneficiary of that allocation (a TV > station) sued and the matter wound up in Federal Court. The court > reaffirmed the DOD's ultimate sovreignity in this matter. It > ultimately got resolved by some allocation juggling when a combination > of the Court, The FCC and the DOD gave the plaintiff some "religion." > > W3JT Excellent point, in my research I saw this handoff or spectrum management authority of the DoD and it makes sense. This is a serious, additional consideration and is all the more reason to get the DHS' blessings. Thanks. -- Drop the alphabet for email Article: 218058 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:20:25 -0400 Message-ID: <90igr4oaklqx.11j4gw2huictq$.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> > On Mon, 3 Oct 2005 11:28:32 -0400, Ari Silversteinn > wrote: > >>Yes, the budget is rich with expected legal expenses. Since DHS has become >>a player in this, we are hopeful that we can get the necessary punch to >>overcome FCC and statutory issues. On Mon, 03 Oct 2005 10:27:09 -0700, Richard Clark wrote: > Hi Ari, > > The various pieces of this jigsaw puzzle is beginning to reveal a > picture here. With the introduction of two governmental > organizations, and their regulations, your "plan" has all the > appearances of being suitably crafted to work on paper. It responds > to the individual issues that any squinty-eyed bureaucrat would demand > be satisfied for his postage sized turf, but in the overall it would > fail miserably, or drive costs so high as to be tainted with the plea > that "aren't people's lives worth the price?" No one, in the end, will care about that, Richard, it's buzz words. The economic hooks are in lessened liabilities and coordinating better emergency evac and site control plans. Money talks here. > Let's see, the original spec calls for a disaster situation that is > confined to within 1 mile; that demands the local population be > informed; that over-rides their usual paths of communication; that > reaches them even when they are not engaged in listening. > > As already pointed out, big sound trucks do wonders, and have worked > well since the beginning of the last century for this purpose. That > kids inside their home can hear the ice-cream truck a mile away is a > testimony to this simplicity. That piece is a given, no argument there, the AM/FM piece is just one more way to insure commo. > Knocking on the door of the local broadcasters and commandeering their > air-time has a time honored tradition of working quite well too. This > involves no more time than getting that expensive mobile power plant > rigged with wide band transmitters working into hugely lossy antenna > systems into the same danger area. After-all, you could as easily > call the first most obvious radio station as them, and you could be > calling the others before they even got on the road. Yes, but as we recently saw, things left to the "if come" often don't "come" ask FEMA. The plan needs to be in place and the control out of the hands of anyone except local/reg/national authority. > The solution demanded is that all radio stations respond to a disaster > network alert and citizens tune to the Civil Defense frequency when so > warned by them. Nothing wrong with that if you know where to tune. I don't, come to think of it. > Is this another administration cut-back that was > shelved as one of those unnecessary "entitlements?" Have they clipped > all the wires to those old Air Raid sirens? When did the lights go > out in FEMA? > > 73's > Richard Clark, KB7QHC MOF, it's an idea that came up over dinner during FEMA/NOLA, don't know about the sirens, all I do know is once FEMA got there, they shutdown most commo inc police in some cases. They want total control so this p[iece has more play at the immediate response (local/state) levels. -- Drop the alphabet for email Article: 218059 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:25:57 -0400 Message-ID: <3hia322eb7xf$.26poszgq5p1y.dlg@40tude.net> References: <3lb613-l4c.ln1@p400bob.personal.cox.net> > Hi Ari > > >>I always wonder whether broadcast at the most common IF frequencies > >>would be a viable alternative? (eg 455khz for AM) Legality issues aside > >>of course... > > > > > > I'm missing your point. Please explain. On Mon, 03 Oct 2005 11:50:35 -0500, Bob Bob wrote: > I apologise if you already know the following! Its pretty basic radio.. Man, don't apologize, I have this semi-advanced understanding that missed a lot of the basics, if you get the drift. Thanks. > Almost every radio receiver on the market works off the "superhetrodyne" > principal where the incoming signal is mixed with a local oscillator > down to an intermediate frequency. This makes receiver design a little > cheaper as you can then put your expensive filtering at one frequency > rather than have something that has to track the actual transmitted > frequency. Got that. > For example a station on the AM band at 870khz is mixed with a local > oscillator of 1325 khz (in the receiver) to get a difference of 455khz. > If the station frequency is changed then one only needs to modify the > local oscillator frequency. This is what the knob on the radio does! lol ok > The most common IF frequency for an AM radio happens to be 455khz so > transmitting on that will mean you will be heard on all AM radios in > close proximity. I dont know off hand know the most common broadcast FM IF > (maybe 10.7MHz or 7.8Mhz) but that should be easy to find. It is > important to make sure that the IF of the fire trucks FM two-way radio > isnt the same or you'll never be able to hear it inside the truck! Now this I did not know! > To "broadcast over" you would need to amplitude modulate the AM band > 455khz TX and frequency modulate the FM broadcast IF frequency. > > > Good advice here, will 20db do it? > > FM is easier to do than AM. I'd factor in maybe 6dB for FM. You might be > able to get by with 12dB for AM but the original station will make some > small amount of noise under it. The important thing is that the person > listening wil be able to understand the content. > > Note that this is of course only relevent when transmitting on the > actual station frequency. Got it. > > Yes, we are shooting for max overbroadcasting but the reality is it is a > > hit and miss proposition. Even the scenario of geo related > obstructions is > > a possibility. On Mon, 03 Oct 2005 11:50:35 -0500, Bob Bob wrote: > Well it shouldnt be that hard to model. Do a AM and FM band coverage > prediction over the freeways etc you are doing the experiment on to > discover what the receive strength will be in dBm. (It doesnt matter > what "gain" you make the RX antenna because it will be the same figure > that is used for your overbroadcast) For every say 200 yard square take > the mean signal of each, then take the 80th percentile as the signal you > have to beat. If that was (say) -80dBm you want -74dBm (for FM) at the > maximum operating distance (was it a mile each way?) You then reverse > model that to determine what the TX EIRP of the thing on the truck has > to be. > > There are bound to be contract houses that will do this prediction for > you. I use to work for one that had the software and I have some GPL > versions myself. I cant do MF (ie AM broadcast) though. Found the expertise for that and there is a chunk of open source stuff out there, freeware. > > Being in a tunnel of course there werent really any > >>licensing issues. > > > Is that peculiar to Aus? On Mon, 03 Oct 2005 11:50:35 -0500, Bob Bob wrote: > The licensing issue or the tunnel? Tunnel rebroadcast is pretty common > around the world. The company I worked for also did one in Indonesia. > Its also used in underground mines. > > > Very nice, congrats on that. Was it Yagi technology or fractal? > > Err, the leaky coax was just a 2km run of an Andrews product that has > leaky holes in the shield. It was fed in the middle with a wide band > splitter and terminated with 50 ohmss at each end. Its quite a common > thing to do in underground environments. (Buildings too) Handy for two > way radio as well as cell phones. > > The AM thing was just a very long terminated (600r) wire. > > None of the above are yagi or fractal > > Cheers Bob Thanks, Bob, I'm all overYagied and underfractalled. lol -- Drop the alphabet for email Article: 218060 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: The Cavity Magnetron. Date: Mon, 3 Oct 2005 20:24:01 +0000 (UTC) Message-ID: References: <11jgf66o5ba6i4d@corp.supernews.com> > Reg, I think you're tilting at windmills. > ======================================= Dave, First I am called Punchinello, and now Don Quixote is implied. Yet you have repeatedly said "Reg is correct". The only thing I have ever asked is to change the NAME. It is the NAME itself which causes ill-educated IEEE members and befuddled university professors to become old wives. They are reduced to CB-ers who perhaps can be forgiven for being fooled just by a NAME. They actually believe the thing measures SWR on a line which does not exist. Or they find a line which does exist but on which it is impossible for the thing to measure anything because it is located in the wrong place. Their contorted imaginations somehow allow them to argue interminably between themselves but without ever coming to sensible conclusions on which they can agree. The evidence of battles about waves, reflections, re-reflections, virtual reflections, conjugate matches, etc, etc, is littered around these newsgroups. And it's all due to a misnomer. Just change the name of the so-called SWR meter and 50 years of bitter warfare will revert once again to blessed peace and an understanding of how things really work. Sack your lawyers. And if anybody should think I take all this seriously then think again. ;o) ---- Reg, G4FGQ Article: 218061 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:27:22 -0400 Message-ID: <1c1ierphijd61.1gixe3w1yrhgb$.dlg@40tude.net> References: <1fybqs5xy9vj4$.1qc8f33ae8wvw$.dlg@40tude.net> On Mon, 03 Oct 2005 12:44:20 -0400, J. Teske wrote: > On Mon, 3 Oct 2005 11:52:49 -0400, Ari Silversteinn > >>> >>> I think the problem here is not the technology, but a fundamental >>> misconception of what it is you are trying to prove and who is likely >>> to be your audience. At this point you do not need an engineer, you >>> need a sociologist. >>> >>> W3JT >> >>A sociologist? > > Yeah, to figure out what has to be done to get the audience to listen > to you. A psychologist might also work. Gee, are you trying to hurt my feelings? -- Drop the alphabet for email Article: 218062 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: UWB pulse signal has no DC? Why? Date: Mon, 03 Oct 2005 13:23:04 -0700 Message-ID: References: <1127857483.866370.308610@z14g2000cwz.googlegroups.com> <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> Cecil Moore wrote: > Say Jim, what is the frequency of virtual photons? Are you asking me what's "nu"? :-) I always say it's c over lambda. For photons it's E/h. You can be the local expert on virtual photons if you want, Cecil. I'm only on a need to know basis with them. 73, ac6xg Article: 218063 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:31:41 -0400 Message-ID: References: <16583-4340AD47-680@storefull-3252.bay.webtv.net> <17tegkmvjr1j9.3a5f8ahg3ekq$.dlg@40tude.net> > On Mon, 3 Oct 2005 11:57:50 -0400, Ari Silversteinn > wrote: >>> You don`t need a radio tire truck. You need a SOUND TRUCK with an AIR >>> HORN to get the audience`s attention to listen to the message. >>I have seen these systems and they have failed to do two things. >>Be heard in a modern car with loud radio and great insulation and 2) pass >>the populace acceptance test. On Mon, 03 Oct 2005 09:56:25 -0700, Richard Clark wrote: > And you've offered this is during an obvious emergency? : The acoustic testing has been done, yes, and the PA is obviously intrusive to the nth degree and is not a panacea for all emergency commo. > 1 Why would they play music loudly in an insulated car when doom is > on their heels? Because they haven't yet been informed, perhaps. > 2 Why would neighbors complain of noise telling them they were about > to be die? It's not always a "death or flee" scenario, it could be hazardous but not deadly. > Richard's description adequately suits: > Local - that would reach out approximately 1 mile and "overbroadcast" > to those immediately in danger within a stationary site. > > Your objections are more tailored to suit your solution than the > problem. > > 73's > Richard Clark, KB7QHC I have a client who is much more knowledgeable in these situations than I am, maybe even you. It's a custom build, not an Ari build. -- Drop the alphabet for email Article: 218064 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:33:52 -0400 Message-ID: <1lb9rnabij6q8.1qdlbba6ct3dh.dlg@40tude.net> References: <3po2k11ti506b359m27i8np3cun993i26u@4ax.com> > On Sun, 2 Oct 2005 18:29:13 -0400, Ari Silversteinn > wrote: > >>Reading about LPAM, this looks technically possible but one concern I have >>is antennae size. A fire truck, for instance, could have an antenna mounted >>on its front, and up to 4 feet over the top of its roof, so we might look >>at as much as 20 feet of length. I realize this places us over the 3 meter >>max so one of the ???? is whether LFAM is realistic. On Mon, 03 Oct 2005 10:05:07 -0700, Richard Clark wrote: > Hi Ari, > > As you have described it, and have seen the discussion in regard to > the need for ERP - you are so deep in the debit column with AM power > EQUAL to a local broadcaster, that to climb out of that hole would be > prohibitive. READ: no fire truck has a power plant sufficient to > cover both the antenna system losses AND "overbroadcast" as you > desire. And this is for ONE station only. Imagine your broader > mandate to "overbroadcast" all local stations and that hole just gets > deeper. OK, so we supply the amplification. >>Am I way off base here, can any antennae, fractal or other, or any AM >>antennae technology, be utilized to design an antenna and propagate this >>type of signal? > > With such a plea, to the savvy it reveals you are in over your head. > > 73's > Richard Clark, KB7QHC Doesn't matter if I'm in over my head, the technical side is one I only need to be able to commo on, there will be others who will be cast with this task. -- Drop the alphabet for email Article: 218065 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 16:35:56 -0400 Message-ID: <1pbrbzestnlq2.15m7emnaa4mdh$.dlg@40tude.net> References: On Mon, 03 Oct 2005 13:37:49 -0500, Ben Jackson wrote: > On 2005-10-02, Ari Silversteinn wrote: >> This would be an "overbroadcast" (my term) >> in that it would override local AM radio broadcasting to reach into cars, > > My experience with AM (on the aircraft band) is that two transmitters > at the same time yields a horrible squeal and nothing else. The louder > station (usually on the ground with hundreds of watts) has no particular > advantage over the other station (usually in the air with 5-10 watts). > In other words, there is no effect like FM capture. Are you saying that if I am attempting an overbroadcast on, say, 680 AM and the station is doing the same, and I am 12 db + greater, that all we will get is squeal? -- Drop the alphabet for email Article: 218066 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: UWB pulse signal has no DC? Why? References: <1127857483.866370.308610@z14g2000cwz.googlegroups.com> <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> Message-ID: <%Dg0f.501$we3.212@newssvr13.news.prodigy.com> Date: Mon, 03 Oct 2005 20:37:15 GMT Jim Kelley wrote: > You can be the local expert on virtual photons if you want, Cecil. I'm > only on a need to know basis with them. I understand coherent photons emitted by free electrons being accelerated and decelerated by RF currents on a wire antenna. I don't know much about virtual photons. I was hoping that a physics guru would know. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218067 of rec.radio.amateur.antenna From: "Hal Rosser" References: Subject: Re: Colinear question Message-ID: Date: Mon, 3 Oct 2005 16:43:32 -0400 yes Article: 218068 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: The Cavity Magnetron. References: <11jgf66o5ba6i4d@corp.supernews.com> Message-ID: Date: Mon, 03 Oct 2005 20:47:16 GMT Reg Edwards wrote: > Or they find a line which does exist but on which it is > impossible for the thing to measure anything because it is located in > the wrong place. Reg, the SWR meter may be smarter than you think. Here's an experiment for you. The system is lossless. XMTR--a--1WL 50 ohm--b--1WL 75 ohm--c--1WL 92 ohm--d--load An SWR meter calibrated for 50 ohms will read the SWR on the 50 ohm feedline when installed at points a,b,c, or d. An SWR meter calibrated for 75 ohms will read the SWR on the 75 ohm feedline when installed at points a,b,c, or d. An SWR meter calibrated for 92 ohms will read the SWR on the 92 ohm feedline when installed at points a,b,c, or d. Now Reg, you have to admit that an SWR meter that can read the SWR on the 92 ohm feedline when installed at point 'a' is a darned smart meter. :-) -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218069 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Emergency Messaging And AM References: <1pbrbzestnlq2.15m7emnaa4mdh$.dlg@40tude.net> Message-ID: <1Tg0f.505$we3.199@newssvr13.news.prodigy.com> Date: Mon, 03 Oct 2005 20:53:17 GMT Ari Silversteinn wrote: > Are you saying that if I am attempting an overbroadcast on, say, 680 AM and > the station is doing the same, and I am 12 db + greater, that all we will > get is squeal? One signal is the Beat Frequency Oscillator. I am amazed that no one has thought of this perfect solution before. If Morse code were required for all driver's licenses, then all you have to do is furnish a CW carrier wave. The two signals would mix and the squeal would be Morse code which would carry the emergency information. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218070 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 17:11:22 -0400 Message-ID: References: <1pbrbzestnlq2.15m7emnaa4mdh$.dlg@40tude.net> <1Tg0f.505$we3.199@newssvr13.news.prodigy.com> On Mon, 03 Oct 2005 20:53:17 GMT, Cecil Moore wrote: > Ari Silversteinn wrote: >> Are you saying that if I am attempting an overbroadcast on, say, 680 AM and >> the station is doing the same, and I am 12 db + greater, that all we will >> get is squeal? > > One signal is the Beat Frequency Oscillator. I am amazed > that no one has thought of this perfect solution before. > > If Morse code were required for all driver's licenses, then > all you have to do is furnish a CW carrier wave. The two > signals would mix and the squeal would be Morse code which > would carry the emergency information. What if your fat as a whale and your DL is wedged up your crack in your back pocket? -- Drop the alphabet for email Article: 218071 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: The Cavity Magnetron. Date: Mon, 3 Oct 2005 21:11:58 +0000 (UTC) Message-ID: References: <11jgf66o5ba6i4d@corp.supernews.com> "Cecil Moore" wrote in message news:oNg0f.504$we3.12@newssvr13.news.prodigy.com... > Reg Edwards wrote: > > Or they find a line which does exist but on which it is > > impossible for the thing to measure anything because it is located in > > the wrong place. > > Reg, the SWR meter may be smarter than you think. Here's > an experiment for you. The system is lossless. > > XMTR--a--1WL 50 ohm--b--1WL 75 ohm--c--1WL 92 ohm--d--load > > An SWR meter calibrated for 50 ohms will read the SWR on > the 50 ohm feedline when installed at points a,b,c, or d. > > An SWR meter calibrated for 75 ohms will read the SWR on > the 75 ohm feedline when installed at points a,b,c, or d. > > An SWR meter calibrated for 92 ohms will read the SWR on > the 92 ohm feedline when installed at points a,b,c, or d. > > Now Reg, you have to admit that an SWR meter that can read > the SWR on the 92 ohm feedline when installed at point 'a' > is a darned smart meter. :-) > -- > 73, Cecil, http://www.qsl.net/w5dxp ========================================= Cec, as usual your message is full of implied "ifs". Of what use is a meter which tells you what you already know? It can be dispensed with. --- Reg. Article: 218072 of rec.radio.amateur.antenna From: Steven Fritts Subject: Re: EXP 14 Hygain Antenna question Message-ID: References: Date: Mon, 03 Oct 2005 17:15:57 -0400 No review found on EHAM about that antenna On Mon, 03 Oct 2005 12:39:01 -0400, Steven Fritts wrote: >Does anyone have any experience wirth this antenna? I need pros or >cons on it as I may be purchasing one soon. > >Thanks > >Steve W4SEF Article: 218073 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Emergency Messaging, AM/FM *On Locomotive* Date: Mon, 3 Oct 2005 17:19:42 -0400 Message-ID: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> DHS has proposed a change in scenario. They want an on locomotive alerting system that could be commandeered and driven at, near or about a disaster site. Everything else stays more or less the same, overbroadcasting on local AM/FM, power off the locomotive, selective or full frequency broadcasting, train (s) to be in motion at all times. 20-30 second messages that would also combine a message to be aware that a locomotive (at speed) will be flying by the at grade crossings. Comments? -- Drop the alphabet for email Article: 218074 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: UWB pulse signal has no DC? Why? Date: Mon, 03 Oct 2005 14:27:07 -0700 Message-ID: References: <1127857483.866370.308610@z14g2000cwz.googlegroups.com> <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> <%Dg0f.501$we3.212@newssvr13.news.prodigy.com> Cecil Moore wrote: > Jim Kelley wrote: > >> You can be the local expert on virtual photons if you want, Cecil. >> I'm only on a need to know basis with them. > > > I understand coherent photons emitted by free electrons being > accelerated and decelerated by RF currents on a wire antenna. > I don't know much about virtual photons. I was hoping that a > physics guru would know. A physics guru might say that if it's a photon, its frequency is E/h unless one of the virtues of being 'virtual' is that its frequency may or may not be equal to E/h. Perhaps it's greatest virtue might even be that you can attribute any physical characteristic you want to it - not unlike some of the other virtual entities. ;-) 73 de ac6xg Article: 218075 of rec.radio.amateur.antenna From: Steven Fritts Subject: Re: EXP 14 Hygain Antenna question Message-ID: <9o83k1lskpf9mojven4u81lm80sl1abcvt@4ax.com> References: Date: Mon, 03 Oct 2005 17:31:40 -0400 My apologies -found the article. On Mon, 03 Oct 2005 12:39:01 -0400, Steven Fritts wrote: >Does anyone have any experience wirth this antenna? I need pros or >cons on it as I may be purchasing one soon. > >Thanks > >Steve W4SEF Article: 218076 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: The Cavity Magnetron. References: <11jgf66o5ba6i4d@corp.supernews.com> Message-ID: Date: Mon, 03 Oct 2005 21:35:24 GMT Reg Edwards wrote: >>Now Reg, you have to admit that an SWR meter that can read >>the SWR on the 92 ohm feedline when installed at point 'a' >>is a darned smart meter. :-) > Of what use is a meter which tells you what you already know? I don't already know it, Reg. The impedance of the load is unknown so the SWR is unknown until measured. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218077 of rec.radio.amateur.antenna From: Lance Orner Subject: Dipole on a hill? Farther from ground or farther up the hill? Message-ID: Date: Mon, 03 Oct 2005 20:25:34 GMT Just getting back into HF, and I'm trying to get an antenna up on my small lot which backs up to a hillside. There are two locations available without erecting more infrastructure. One would be about 20 feet up at the base of the hill, and the other is about 50 feet up the hill, but only 10 feet off the ground. So the question: Is it more important to have the antenna farther >from ground, or father up the hill but closer to ground? In the future, I'd love to put a tall antenna at the tallest part of the hill, but I'm looking for something temporary right now. Thanks. -- Lance Orner -- K7API lance@orner.net Article: 218078 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> Subject: Re: Emergency Messaging And AM Date: Mon, 3 Oct 2005 17:58:33 -0400 Message-ID: <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. "Ari Silversteinn" wrote in message news:c9gqhrx7nggh$.1hmwsp16r4gsh.dlg@40tude.net... > On Mon, 3 Oct 2005 12:01:14 -0400, Fred W4JLE wrote: > > > In that case, simply modify the sign to "Tune to 560, it could save your > > life" and use a discrete frequency low power transmitter. > > I assume you mean to take up an unused local channel? Or to bargain for > time on a used one? > > Both ideas make sense. > -- > Drop the alphabet for email > Article: 218079 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: UWB pulse signal has no DC? Why? Date: Mon, 03 Oct 2005 15:07:55 -0700 Message-ID: References: <1127891612.179165.113960@g47g2000cwa.googlegroups.com> <6hG_e.3369$KQ5.1335@newssvr12.news.prodigy.com> <%Dg0f.501$we3.212@newssvr13.news.prodigy.com> <5093k11olhbqeu5jr3rd8057uf8jeg8r33@4ax.com> Richard Clark wrote: > Are we verging on the shadow of a photon? Only the shadow knows. It's a quantum effect. ac6xg Article: 218080 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: <04i0f.15845$iM2.1296048@news.xtra.co.nz> Date: Tue, 4 Oct 2005 11:15:23 +1300 "Ari Silversteinn" wrote in message news:1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net... > DHS has proposed a change in scenario. They want an on locomotive alerting > system that could be commandeered and driven at, near or about a disaster > site. Everything else stays more or less the same, overbroadcasting on > local AM/FM, power off the locomotive, selective or full frequency > broadcasting, train (s) to be in motion at all times. 20-30 second > messages > that would also combine a message to be aware that a locomotive (at speed) > will be flying by the at grade crossings. > > Comments? > -- Impractical, for the same reasons cited earlier. What's wrong with electronic message boards on trailers fitted with sirens and, if deemed necessarily, a very large guy with a gun to maintain interest. You may find that sci.electronic.misc or sci.electronic.design may be more relevant, since it's commercial/military and not amateur. Mind you, they may also be less polite..... Ken Article: 218081 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup Date: Mon, 3 Oct 2005 22:20:11 +0000 (UTC) Message-ID: References: "Bob Bob" wrote in message news:u62813-qhf.ln1@p400bob.personal.cox.net... > Hi Reg > > The two pieces of coax are only meant to be a 100 ohm balanced Q section > to translate the antenna Z to close to that of the main feedline (50r). > I could do the same if I had some 100r open/ribbon feedline. > > The outer conductors/shield should be at zero potential and as such > preserve the Z between the two inner conductors. This is handy in that > the coaxes dont have to be bound close together and could be fed through > a non metallic conduit without problems. > > Have I made any sense? > Yes, that works OK. You have acheived your objective. My only comment is that the inner coaxial conductors are very thin and depending on length they may be a little lossy. You could use a twisted pair of thicker wires insulated with thin plastic which would have approximately the same 100-ohm impedance. The actual impedance is not very critical. This would also eliminate stray capacitance of the coax outer conductors to their surroundings. Although that is not likely to cause much trouble anyway. ---- Reg. Article: 218082 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Winding details for antenna choke ? Date: Mon, 3 Oct 2005 22:32:51 +0000 (UTC) Message-ID: References: Dave, please tell me whether you ran the program OK. The numbers are correct but I was not happy with the introductory notes. Did they make sense to you? ---- Reg, G4FGQ "David" wrote in message news:gJm%e.3900$U51.2554@news-server.bigpond.net.au... > Thank you. > > Reg Edwards wrote: > > For design of solenoid chokes wound with coax cable, download program > > SELFRES3 from website below. > > -- > > ........................................................... > > Regards from Reg, G4FGQ > > For Free Radio Design Software go to > > http://www.btinternet.com/~g4fgq.regp > > ........................................................... > > > > Article: 218083 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: Emergency Messaging And AM Date: Mon, 03 Oct 2005 17:55:13 -0500 Message-ID: <11k3dmkqbnho149@corp.supernews.com> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> Ari Silversteinn wrote: > >>>Do we have to blanket or only blanket each locale, that is, the >>>broadcasting stations of each locale? >>> >>>Not only will we miss those no AM/FM listeners, we will miss those that >>>don't have their radios on. An aggressive, road sign campaign is planned >>>something like " Turn On Your Radio, It Could Save Your Life" type of thing >>>near each incident site. > > > On Mon, 03 Oct 2005 12:58:40 -0400, J. Teske wrote: > > >>While Florida may have laws to this effect, in fact they are >>unenforcable because of federal preemption for all radio matters. >>Still illegal, just the wrong enforcement entity. A state or locality >>cannot for example legislate on TVI matters (though many have tried.) >>When they try, the FCC will send a notice to the locals that they are >>in charge and will handle enforcement. Unfortunately the FCC is >>unwilling to get involved in the matter of private contracts such as >>antenna exclusions in housing developments. > > > Is there a reason that the locals try to overwrite Fed law then? > > >>That said, be aware that when it comes to radio useage in the US, the >>FCC is actually NOT the ultimate authority. They are responsible only >>for those frequencies which a military controlled panel has ceded to >>the FCC for administrative purposes. I can't remember the name right >>off hand, but during my federal career, I had to work with them and we >>actually were able to override an FCC allocation because it interfered >>with a military application. While the FCC played ball with the DOD >>outfit I worked for, the ultimate beneficiary of that allocation (a TV >>station) sued and the matter wound up in Federal Court. The court >>reaffirmed the DOD's ultimate sovreignity in this matter. It >>ultimately got resolved by some allocation juggling when a combination >>of the Court, The FCC and the DOD gave the plaintiff some "religion." >> >>W3JT > > > Excellent point, in my research I saw this handoff or spectrum management > authority of the DoD and it makes sense. This is a serious, additional > consideration and is all the more reason to get the DHS' blessings. > > Thanks. Actually the DOD does not have any authority over radio spectrum. There are two federal agencies that do. One is the FCC, which we all know and love, the other is NTIA, the National Telecomunications Information Agency. NITA controls all federal radio frequencies. Since the DOD is a Federal Agency their frequencies are controled by NTIA the same as the FBI, CIA Secret Service, Dept of Homeland Security and any other federal alphabet soup agency. Dave N a FCC and a NTIA user Article: 218084 of rec.radio.amateur.antenna From: "Dr.Ace" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <04i0f.15845$iM2.1296048@news.xtra.co.nz> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Mon, 3 Oct 2005 17:57:35 -0500 Message-ID: <55812$4341b749$4e10530$14651@DIALUPUSA.NET> Snipped > > You may find that sci.electronic.misc or sci.electronic.design may be more > relevant, since it's commercial/military and not amateur. Mind you, they > may also be less polite..... > > Ken > > Wow , there are news groups that are less polite than some of the people in this news group. That's sad. Unnecessary rudeness is unnecessary and rude. Ace - WH2T Article: 218085 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: The CFA antenna is still with us Date: Mon, 3 Oct 2005 23:03:52 +0000 (UTC) Message-ID: References: <434185E7.CAC05318@shaw.ca> "Irv Finkleman" wrote > Perhaps it will perform better upside-down! > ================================ I havn't laughed so much in ages. It really hurts. ---- Reg. Article: 218086 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> Date: Mon, 03 Oct 2005 23:09:59 GMT On Sun, 02 Oct 2005 21:26:48 -0700, Richard Clark wrote: >On Mon, 03 Oct 2005 03:56:24 GMT, kashe@sonic.net wrote: > >> ISP location != subscriber location. One subscriber is in New >>Zealand. > >Trying to convince us you pay trans-oceanic toll charges for a modem Who said modem? >hookup? One subscriber != me. And being in New Zealand has you/them/whomever offering: ... an incomplete sentence? >>>> I'm not hearing any interest in turning streets near me into >>>>canals. > >Yeh - sure. Damn straight. Article: 218087 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Date: Mon, 03 Oct 2005 23:16:33 GMT On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn wrote: >DHS has proposed a change in scenario. They want an on locomotive alerting >system that could be commandeered and driven at, near or about a disaster >site. Everything else stays more or less the same, overbroadcasting on >local AM/FM, power off the locomotive, selective or full frequency >broadcasting, train (s) to be in motion at all times. 20-30 second messages >that would also combine a message to be aware that a locomotive (at speed) >will be flying by the at grade crossings. > >Comments? Tracks across Lake Ponchartrain fell in. Granted they were put back in service faster than anything the government had connection to. Article: 218088 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <04i0f.15845$iM2.1296048@news.xtra.co.nz> <55812$4341b749$4e10530$14651@DIALUPUSA.NET> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: <38j0f.15852$iM2.1293337@news.xtra.co.nz> Date: Tue, 4 Oct 2005 12:27:58 +1300 "Dr.Ace" wrote in message news:55812$4341b749$4e10530$14651@DIALUPUSA.NET... > > Snipped >> >> You may find that sci.electronic.misc or sci.electronic.design may be >> more relevant, since it's commercial/military and not amateur. Mind you, >> they may also be less polite..... >> >> Ken >> >> > > Wow , there are news groups that are less polite than some of the people > in this news group. > That's sad. Unnecessary rudeness is unnecessary and rude. > Ace - WH2T > A couple of threads aside, this is a pretty good group. So are the others I mentioned, but they don't tolerate the sort of technical vagueness that's being displayed in this thread. Cheers. Ken Article: 218089 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Tue, 4 Oct 2005 12:29:52 +1300 wrote in message news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn > wrote: > >>DHS has proposed a change in scenario. They want an on locomotive alerting >>system that could be commandeered and driven at, near or about a disaster >>site. Everything else stays more or less the same, overbroadcasting on >>local AM/FM, power off the locomotive, selective or full frequency >>broadcasting, train (s) to be in motion at all times. 20-30 second >>messages >>that would also combine a message to be aware that a locomotive (at speed) >>will be flying by the at grade crossings. >> >>Comments? > > Tracks across Lake Ponchartrain fell in. > > Granted they were put back in service faster than anything the > government had connection to. Why a loco anyway? It would appear to be the mistaken assumption that anything that big must have power to burn on anything plugged in by a user. Not the case - the power from a loco is, not surprisingly, applied to the tracks. The electric generators used for powering gear other than the train's vitals are not high power. Ken Article: 218090 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Tue, 4 Oct 2005 13:03:57 +1300 "Mike Coslo" wrote in message news:46ednZll5fNJXtzeRVn-tw@adelphia.com... > Ken Taylor wrote: >> wrote in message >> news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... >> >>>On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn >>> wrote: >>> >>> >>>>DHS has proposed a change in scenario. They want an on locomotive >>>>alerting >>>>system that could be commandeered and driven at, near or about a >>>>disaster >>>>site. Everything else stays more or less the same, overbroadcasting on >>>>local AM/FM, power off the locomotive, selective or full frequency >>>>broadcasting, train (s) to be in motion at all times. 20-30 second >>>>messages >>>>that would also combine a message to be aware that a locomotive (at >>>>speed) >>>>will be flying by the at grade crossings. >>>> >>>>Comments? >>> >>>Tracks across Lake Ponchartrain fell in. >>> >>>Granted they were put back in service faster than anything the >>>government had connection to. >> >> >> Why a loco anyway? It would appear to be the mistaken assumption that >> anything that big must have power to burn on anything plugged in by a >> user. Not the case - the power from a loco is, not surprisingly, applied >> to the tracks. The electric generators used for powering gear other than >> the train's vitals are not high power. > > Guys, don't ya know that this guy is trolling and caught way more than the > daily creel limit? > > - Mike KB3EIA - Well, he's not a troll in that he's making it up as he goes - it appears he really is hoping to do for his company what he says (source: Google). However it's a job which really equates to: A valid way of doing business, but still a crock. Ken Article: 218091 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: OT: Military Radio Question Date: Mon, 3 Oct 2005 17:26:04 -0700 Message-ID: <11k3j0s7dujl92a@corp.supernews.com> I posted this on another group, but you all seem really smart here. I have a military radio (PRC-1099) and a battery. I want to buy a power supply that will power the radio but which can also be used to charge the battery. The radio needs a 12V power supply to run. The battery is a lead-calcium type, and is supposed to be charged at 1A for 5 to 6 hours. Buying a 12V power supply is easy, but do supplies normally have a variable current output? I am not an authority on power supplies or charging batteries, so I need some help here. Thanks, Rod KI7CQ Article: 218092 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup References: Message-ID: <0au813-9eg.ln1@p400bob.personal.cox.net> Date: Mon, 03 Oct 2005 19:17:36 -0500 Mmm okay, well considering the rest of the feedline is RG58 I guess the matching section has less loss per unit length! (The Q section is 3 point something metres long - 1/4 wave at 0.66 vf) I havent been playing with HF that long. I must admit though that I tend to ignore the losses that I would worry a lot about at VHF/UHF. Oh BTW I tried one of your pgms under Linux Wine the other day. Dies with some kind of DOS memory alloc error or something. I'll make a note of it next time and do a little research if your interested. Cheers Bob Reg Edwards wrote: > Yes, that works OK. You have acheived your objective. > > My only comment is that the inner coaxial conductors are very thin and > depending on length they may be a little lossy. You could use a > twisted pair of thicker wires insulated with thin plastic which would > have approximately the same 100-ohm impedance. The actual impedance is > not very critical. > > This would also eliminate stray capacitance of the coax outer > conductors to their surroundings. Although that is not likely to > cause much trouble anyway. > ---- > Reg. > > Article: 218093 of rec.radio.amateur.antenna From: Owen Duffy Subject: Noise Figure measurement - Y factor calculator Message-ID: Date: Tue, 04 Oct 2005 01:35:45 GMT I have developed a simple tool to assist NF measurements by performing the calcs in a two stage cal/measure process, and documenting the test. So, if you interest in antennas runs to overall receive system performance, you may find this calculator handy. Works in IE and Firefox. Tested to a fair extent, but it could contain defects... if you find any, please let me know. http://www.vk1od.net/sc/y.htm Owen -- Article: 218094 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Mon, 3 Oct 2005 21:44:09 -0400 Message-ID: <497c5$4341de9e$97d558d8$12886@ALLTEL.NET> That would be much easier, simply sweep a modulated oscillator across the band. With a couple of adjustments it would be easy to emulate a train whistle, a somewhat universal warning. wrote in message news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn > wrote: > > >DHS has proposed a change in scenario. They want an on locomotive alerting > >system that could be commandeered and driven at, near or about a disaster > >site. Everything else stays more or less the same, overbroadcasting on > >local AM/FM, power off the locomotive, selective or full frequency > >broadcasting, train (s) to be in motion at all times. 20-30 second messages > >that would also combine a message to be aware that a locomotive (at speed) > >will be flying by the at grade crossings. > > > >Comments? > > Tracks across Lake Ponchartrain fell in. > > Granted they were put back in service faster than anything the > government had connection to. Article: 218095 of rec.radio.amateur.antenna From: "Ken Taylor" References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128390761.510351.170710@g43g2000cwa.googlegroups.com> Subject: Re: Emergency Messaging And AM Message-ID: Date: Tue, 4 Oct 2005 14:57:01 +1300 wrote in message news:1128390761.510351.170710@g43g2000cwa.googlegroups.com... > Wonder no longer, because broadcasing at IF frequencies has been for > year the standard in the US. In spite of some rather silly speculative > posts, this mechanism has proved itself for more than 10-years here. > > In a confined space such as a tunnel, a transmitter of 10-watts more > than sufficint to get the job done, and using nothing more > sophisticated than a simple wire radiator running the length of the > tunnel. > > In Boston, we also retransmit commercial radio broadcasts into our > tunnels, but that requires equipment dedicated to each radio channel > that we re-broadcast, and that becomes very costly after 10 stations or > so, hence there is a limit. > > The real challenge is in maintaining emergency communications to the > outside from within our tunnels. All are serviced by the traditional > leaky coax that runs along the top of the tunnel, but considering that > all of these emergency services operate on their own indepdendent > frequency bands, so servicing them simulteously becomes somwhat > problematic. particularly when hand-held, low power devices enter the > big picture. > > Harry C. > All agreed, but that is in a tunnel, which has the advantage of not having to overcome the still-received commercial stations. The OP wants to do this out in the open, anywhere, any time. He also wanted to do it while driving at high speed for some reason, but I think he's quietly shelved that part of the idea. Cheers. Ken Article: 218096 of rec.radio.amateur.antenna Date: Mon, 03 Oct 2005 21:08:51 -0500 From: Tom Ring Subject: Re: Emergency Messaging, AM/FM *On Locomotive* References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <497c5$4341de9e$97d558d8$12886@ALLTEL.NET> Message-ID: <4341e434$0$3754$39cecf19@news.twtelecom.net> WOW! None of us Northerners would have thought of somethjing that sofisteekayted. tom K0TAR Fred W4JLE wrote: > That would be much easier, simply sweep a modulated oscillator across the > band. With a couple of adjustments it would be easy to emulate a train > whistle, a somewhat universal warning. > > wrote in message > news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... > >>On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn >> wrote: >> >> >>>DHS has proposed a change in scenario. They want an on locomotive > > alerting > >>>system that could be commandeered and driven at, near or about a disaster >>>site. Everything else stays more or less the same, overbroadcasting on >>>local AM/FM, power off the locomotive, selective or full frequency >>>broadcasting, train (s) to be in motion at all times. 20-30 second > > messages > >>>that would also combine a message to be aware that a locomotive (at > > speed) > >>>will be flying by the at grade crossings. >>> >>>Comments? >> >>Tracks across Lake Ponchartrain fell in. >> >>Granted they were put back in service faster than anything the >>government had connection to. > > > Article: 218097 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11k3j0s7dujl92a@corp.supernews.com> Subject: Re: Military Radio Question Date: Mon, 3 Oct 2005 22:10:02 -0400 Message-ID: <1cbb0$4341e4af$97d558d8$26948@ALLTEL.NET> Not that simple Rod, as the battery charges, and the voltage changes, current from most supplies follow the voltage. What I mean by that is that with a discharged battery you get more current than you desire at the start of the charge cycle. I use a device that is used to charge model airplane batteries. The same supply you use to power the radio will power the current limited charger. Check your local Hobby Shop or one of the on-line sites. I bought one for about $49.00 that will charge Gel Cells, Ni-Cads, etc. Of course you can simply use a wall wart, but the money you think you saved will be spent in battery replacement. "Rod Maupin" wrote in message news:11k3j0s7dujl92a@corp.supernews.com... > I posted this on another group, but you all seem really smart here. > > I have a military radio (PRC-1099) and a battery. I want to buy a power > supply that will power the radio but which can also be used to charge the > battery. The radio needs a 12V power supply to run. The battery is a > lead-calcium type, and is supposed to be charged at 1A for 5 to 6 hours. > > Buying a 12V power supply is easy, but do supplies normally have a variable > current output? I am not an authority on power supplies or charging > batteries, so I need some help here. > > Thanks, > > Rod KI7CQ > > Article: 218098 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Military Radio Question Date: Mon, 3 Oct 2005 19:20:51 -0700 Message-ID: <11k3po2qf3gt18e@corp.supernews.com> References: <11k3j0s7dujl92a@corp.supernews.com> <1cbb0$4341e4af$97d558d8$26948@ALLTEL.NET> I think you just told me what I needed to know. Thanks Fred. Rod KI7CQ Article: 218099 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: OT: Military Radio Question References: <11k3j0s7dujl92a@corp.supernews.com> Message-ID: <1nm0f.8634$oO2.1010@newssvr27.news.prodigy.net> Date: Tue, 04 Oct 2005 03:08:45 GMT Rod Maupin wrote: > I have a military radio (PRC-1099) and a battery. I want to buy a power > supply that will power the radio but which can also be used to charge the > battery. The radio needs a 12V power supply to run. The battery is a > lead-calcium type, and is supposed to be charged at 1A for 5 to 6 hours. > > Buying a 12V power supply is easy, but do supplies normally have a variable > current output? I am not an authority on power supplies or charging > batteries, so I need some help here. What are the constant voltage charging specs on the battery? (if any) -- 73, Cecil http://www.qsl.net/w5dxp Article: 218100 of rec.radio.amateur.antenna From: "John Doe" <@127.0.0.1> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 13:26:05 +1000 Message-ID: <4341f644$0$22741$afc38c87@news.optusnet.com.au> "Richard Clark" wrote in message news:6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com... > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn > wrote: > >Comments? > What a troll. But Wait, There's more! Emergency Messaging, over broadcasting on AM/FM/SCA/IBOC/Satellite/TV/HDTV/Mobile Phone/ On Ships to sail to the road accidents, on Submarines, Aircraft & Satellites. ;-) Article: 218101 of rec.radio.amateur.antenna From: Uncle Ted Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Date: Tue, 04 Oct 2005 00:12:14 -0400 Message-ID: References: <43313df9$0$253$14726298@news.sunsite.dk> <4338A687.8D5B94DF@earthlink.net> <4338D057.B9B48493@earthlink.net> <8rvoj19bp6umuvfefeo6v87enpmg18pd8m@4ax.com> <84g%e.3872$KQ5.520@newssvr12.news.prodigy.com> <34l1k1h00rlsqgicd6fkg2fi4m490lv31g@4ax.com> On Mon, 03 Oct 2005 23:10:43 GMT, kashe@sonic.net wrote: >On Mon, 03 Oct 2005 14:30:55 -0400, Uncle Ted >wrote: > >>On Mon, 03 Oct 2005 06:51:22 GMT, kashe@sonic.net wrote: >> >> >>>>> As written, they beg to be read as an incomplete syllogism. >>>> >>>>In other words, you made the connection up in your head. Typical. >>> >>> Jesus, another liunatic who thinks he knows all about me. >>>Pompous bastard. >> >>Mr. Pot, meet Mr. Kettle... > > Persuasive logic there, childish one. Yeah, right. Like your little one-line snippets of irrefutable wisdom are persuading anyone... Article: 218102 of rec.radio.amateur.antenna From: "Jerry Martes" References: <11k3j0s7dujl92a@corp.supernews.com> Subject: Re: Military Radio Question Message-ID: <5Ao0f.223$yN6.23@trnddc04> Date: Tue, 04 Oct 2005 05:39:13 GMT "Rod Maupin" wrote in message news:11k3j0s7dujl92a@corp.supernews.com... >I posted this on another group, but you all seem really smart here. > > I have a military radio (PRC-1099) and a battery. I want to buy a power > supply that will power the radio but which can also be used to charge the > battery. The radio needs a 12V power supply to run. The battery is a > lead-calcium type, and is supposed to be charged at 1A for 5 to 6 hours. > > Buying a 12V power supply is easy, but do supplies normally have a > variable current output? I am not an authority on power supplies or > charging batteries, so I need some help here. > > Thanks, > > Rod KI7CQ Rod For what reason is it needed to require the battery to be charged within 6 hours? If it is practical to charge the battery "overnight", the requirements could be much less expensive. There is alot-alot of information on the Internet about charging lead-acid batteries. The lead-Calcium is the type cell commonly used in most automotive autos today. If this was my radio, I'd use a wall wart with a 12 volt lamp in series between the wall wart and the battery. . A 10 volt DC, 1 amp wall wart would probably be close to proper for this radio. The series lamp will limit the charge rate. If the battery terminal voltage is restricted to being no higher than 14.8 volts,the battery will not boil off its electrolyte. Jerry Article: 218103 of rec.radio.amateur.antenna From: "SH" Subject: Connecting several bandpass filters. Message-ID: <43422d26$1@news.wineasy.se> Date: 4 Oct 2005 09:20:06 +0200 Hi I have come up with one of those crazy DYI ideas which I would like to try to implement but one thing still remains. I have two UHF (TV) arial pointing in different directions and would like to connect them together through BP filters to minimize noise. BP = Bandpass Antenna 1: UHF channel (Europe) BP 1 ch 22-37, BP 2 ch40 -44, BP 3 ch 49 - 68/ or high pass Antenna 2: UHF channel (Europe) BP 1 ch 21 / or low pass, BP 2 ch38 -39, BP 3 ch 47 I have found formulas to design each section of BF but how to you connect several BP filters in parallel??? I have investigated some old TV filter and they have a coil (12 WDG) in and out of each BP section but is that the way to do it and how does it influence the design of each BP. The only approach that I can find is to split the signal into three (- 6dB ) then feed each into a BP filter and the Combine them again (-6dB). This will result in each BP section seeing 75 Ohms as they shouland they would not interfere with eachother. Ofcouse i would need a 20 dB amplifier to fix the loss. But is there a better way. Best regards Svend Holby Article: 218104 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Date: Tue, 04 Oct 2005 09:51:46 GMT On Tue, 4 Oct 2005 12:29:52 +1300, "Ken Taylor" wrote: > wrote in message >news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... >> On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn >> wrote: >> >>>DHS has proposed a change in scenario. They want an on locomotive alerting >>>system that could be commandeered and driven at, near or about a disaster >>>site. Everything else stays more or less the same, overbroadcasting on >>>local AM/FM, power off the locomotive, selective or full frequency >>>broadcasting, train (s) to be in motion at all times. 20-30 second >>>messages >>>that would also combine a message to be aware that a locomotive (at speed) >>>will be flying by the at grade crossings. >>> >>>Comments? >> >> Tracks across Lake Ponchartrain fell in. >> >> Granted they were put back in service faster than anything the >> government had connection to. > >Why a loco anyway? It would appear to be the mistaken assumption that >anything that big must have power to burn on anything plugged in by a user. >Not the case - the power from a loco is, not surprisingly, applied to the >tracks. Actually, it's not. What made you bring up tracks anyway -- my reference to the tracks on the lake falling in? My point was that the locomotive is going nowhere there aren't usable tracks. On a diesel-electric locomotive, the generator's output is applied, not to the tracks as you seem to think, but rather through control circuitry to the stator around the axle. It's rather amusing to see a repair yard worker with a set of wheels-and-axle (they're all one single piece, in case you didn't know) clamp a stator around the axle, connect a battery with a pair of short jumper cables and walk the whole arrangement across a concrete floor as though he were walking the family dog. BTW, at 4,000+ horsepower, you could plug in nearly anything a user might want, given proper appliances and the right plug. :-) > The electric generators used for powering gear other than the >train's vitals are not high power. > >Ken > Article: 218105 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> <00f3k1p06ih7ua69rna698mccj164el8qv@4ax.com> Date: Tue, 04 Oct 2005 09:58:00 GMT On Mon, 03 Oct 2005 16:31:58 -0700, Richard Clark wrote: >On Mon, 03 Oct 2005 23:09:59 GMT, kashe@sonic.net wrote: > >>On Sun, 02 Oct 2005 21:26:48 -0700, Richard Clark >>wrote: >> >>>On Mon, 03 Oct 2005 03:56:24 GMT, kashe@sonic.net wrote: >>> >>>> ISP location != subscriber location. One subscriber is in New >>>>Zealand. >>> >>>Trying to convince us you pay trans-oceanic toll charges for a modem >> >> Who said modem? >I did. Look at the attribution line above. I said subscriber. You jumped to the conclusion he was on dialup. >> >>>hookup? >> >> One subscriber != me. >(More than one subscriber != you) == so what? You, fool, chose to assume the one sunscriber was me, as in " ... _you_ pay trans-oceanic toll charges". >> >> And being in New Zealand has you/them/whomever offering: >> >> ... an incomplete sentence? >Now that you interjected an incomplete sentence into it. >> >>>>>> I'm not hearing any interest in turning streets near me into >>>>>>canals. >>> >>>Yeh - sure. >> >> Damn straight. >Telling us you "might" hear interest in turning streets near you into >canals? Might not? - newsflash! Taking I-5 south to I-10 east, you >are 2274 miles or more from even a remote chance with respect to New >Orleans. Christ -- you can't even parse a sentence -- give up. Article: 218106 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup Date: Tue, 4 Oct 2005 11:47:54 +0000 (UTC) Message-ID: References: <0au813-9eg.ln1@p400bob.personal.cox.net> "Bob Bob" wrote in message news:0au813-9eg.ln1@p400bob.personal.cox.net... > Mmm okay, well considering the rest of the feedline is RG58 I guess the > matching section has less loss per unit length! (The Q section is > 3 point something metres long - 1/4 wave at 0.66 vf) > > I havent been playing with HF that long. I must admit though that I tend > to ignore the losses that I would worry a lot about at VHF/UHF. > > Oh BTW I tried one of your pgms under Linux Wine the other day. Dies > with some kind of DOS memory alloc error or something. I'll make a note > of it next time and do a little research if your interested. > > Cheers Bob > > Reg Edwards wrote: > > > Yes, that works OK. You have acheived your objective. > > > > My only comment is that the inner coaxial conductors are very thin and > > depending on length they may be a little lossy. You could use a > > twisted pair of thicker wires insulated with thin plastic which would > > have approximately the same 100-ohm impedance. The actual impedance is > > not very critical. > > > > This would also eliminate stray capacitance of the coax outer > > conductors to their surroundings. Although that is not likely to > > cause much trouble anyway. ========================================== Regarding Linux. There's little or nothing you can do about it. And I'm afraid, sooner or later, future versions of Dos/Windows may not be able to run my programs. Just don't throw away your old computer. ;o) --- Reg, G4FGQ Article: 218107 of rec.radio.amateur.antenna From: Allodoxaphobia Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: 4 Oct 2005 14:12:19 GMT Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn wrote: > DHS has proposed a change in scenario. They want an on locomotive alerting > system that could be commandeered and driven at, near or about a disaster > site. Everything else stays more or less the same, overbroadcasting on > local AM/FM, power off the locomotive, selective or full frequency > broadcasting, train (s) to be in motion at all times. 20-30 second messages > that would also combine a message to be aware that a locomotive (at speed) > will be flying by the at grade crossings. > > Comments? And what are these messages suppose to convey? The target audience already knows it's screwed. We all (outside the screwed zone) saw the blizzard of useless "messages" the government(s) issued during and after Katrina. Just what I need to hear from a locomotive blowing by at 50 mph: "Hi! We're the government and we are here to help you." The best that came out of post-Katrina was from self-help and assistance from non-government organizations. And, the government even thwarted some of that. The inmates are running the asylum: http://www.iht.com/articles/2005/10/02/news/storm.php Ninety-one thousand tons of ice melting in idling 14-wheelers. 73 Jonesy -- Marvin L Jones | jonz | W3DHJ | linux Pueblo, Colorado | @ | Jonesy | OS/2 __ 38.24N 104.55W | config.com | DM78rf | SK Article: 218108 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Military Radio Question References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> Message-ID: Date: Tue, 04 Oct 2005 14:19:00 GMT Jerry Martes wrote: > If the battery terminal voltage is restricted to being no higher than 14.8 > volts,the battery will not boil off its electrolyte. I float my deep-discharge marine backup battery on my Astron 13.6 vdc power supply. If AC fails, I hardly notice it. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218109 of rec.radio.amateur.antenna From: "Wayne P. Muckleroy" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Tue, 04 Oct 2005 14:33:52 GMT Like I said in another thread, "Emergency" implies IMMEDIATE (not planned) danger to life, limb, or property. It seems that, in your proposal, you are PLANNING to use these frequencies instead of more appropriate ones. I would think that you need to create (and supply) a system that is isolated from broadcast frequencies. Wayne- (KC8UIO) "Ari Silversteinn" wrote in message news:1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net... > DHS has proposed a change in scenario. They want an on locomotive alerting > system that could be commandeered and driven at, near or about a disaster > site. Everything else stays more or less the same, overbroadcasting on > local AM/FM, power off the locomotive, selective or full frequency > broadcasting, train (s) to be in motion at all times. 20-30 second > messages > that would also combine a message to be aware that a locomotive (at speed) > will be flying by the at grade crossings. > > Comments? > -- > Drop the alphabet for email Article: 218110 of rec.radio.amateur.antenna From: "John Doe" <@127.0.0.1> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com> <4341f644$0$22741$afc38c87@news.optusnet.com.au> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 00:51:49 +1000 Message-ID: <434296fe$0$29450$afc38c87@news.optusnet.com.au> Durrrrrr, Can anyone spell EAS http://www.fcc.gov/eb/eas/ "John Doe" <@127.0.0.1> wrote in message news:4341f644$0$22741$afc38c87@news.optusnet.com.au... > "Richard Clark" wrote in message > news:6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com... > > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn > > wrote: > > >Comments? > > What a troll. > > But Wait, > There's more! > Emergency Messaging, over broadcasting on > AM/FM/SCA/IBOC/Satellite/TV/HDTV/Mobile Phone/ > On Ships to sail to the road accidents, > on Submarines, Aircraft & Satellites. > ;-) > > Article: 218111 of rec.radio.amateur.antenna From: 'Doc Subject: Re: Dipole on a hill? Farther from ground or farther up the hill? References: Message-ID: Date: Tue, 04 Oct 2005 14:53:25 GMT Lance, The 'first' thing that comes to mind is to get the antenna as high as possible. Then theres the 'second' thing that comes to mind which is which is going to be more practical to do? I'd go for the highest to start with. Nothing says you can't change it later. 'Doc Article: 218112 of rec.radio.amateur.antenna From: "Wayne P. Muckleroy" References: Subject: Re: Emergency Messaging And AM Message-ID: Date: Tue, 04 Oct 2005 14:54:42 GMT Suggestion: Why don't you also broadcast such "emergency" information over the entire spectrum of wireless network frequencies? That way, you could post the information into every Usenet group on the globe. Just like you have done with these postings. "Ari Silversteinn" wrote in message news:r7evtegkcjgt.kuwb55vmxpjg$.dlg@40tude.net... > Crossposted to: > > rec.radio.amateur.antenna,rec.radio.amateur.misc,rec,radio.amateur.equipment > > Novitiate here: > > I am learning AM broadcast basics in particular the issues regarding the > geo-targeted broadcasting of alert messages from moving vehicles. Would > most appreciate any assistance. > > Due to Katrina/Rita, the company I work for has been given the opportunity > to demonstrate a messaging system that would reach out approximately 1 > mile > +/- in transmission deliverance. This would be an "overbroadcast" (my > term) > in that it would override local AM radio broadcasting to reach into cars, > trucks etc. In particular, we are working with a stationary site (a > chemical spill for instance) and an emergency vehicle that would move back > and forth at and through the site, at up to 70 mph, broadcasting an alert, > voice and tone message. > > Reading about LPAM, this looks technically possible but one concern I have > is antennae size. A fire truck, for instance, could have an antenna > mounted > on its front, and up to 4 feet over the top of its roof, so we might look > at as much as 20 feet of length. I realize this places us over the 3 meter > max so one of the ???? is whether LFAM is realistic. > > Am I way off base here, can any antennae, fractal or other, or any AM > antennae technology, be utilized to design an antenna and propagate this > type of signal? > > All comments appreciated. > -- > Drop the alphabet for email Article: 218113 of rec.radio.amateur.antenna From: "Rod Maupin" Subject: Re: Military Radio Question Date: Tue, 4 Oct 2005 08:04:13 -0700 Message-ID: <11k56fd3oubmsf6@corp.supernews.com> References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> The PRC-1099 manual just says what type of battery to use. When I bought the radio, the battery came with it. Actually, I was incorrect. The manual was talking about using different battery types, lead-calcium being one of them, but on the battery it has the following information: On the side ------------ Battery, Rechargeable BB-586/U Nickel Cadmium, Sealed 13.2 Volts, 4.0 Ampere Hours At 0.8 Ampere Bren-Tronics, Inc. Commack, New York On the top ----------- Charging Instructions Recommended charge rate is 1 AMP for 5 to 6 hours. Charging temperature should be 40 deg. F. to 90 deg. F. Thanks for the help, Rod KI7CQ Article: 218114 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:12:33 -0400 Message-ID: <1jdfi56hxbleu$.vosxjmg436ys.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Mon, 3 Oct 2005 21:41:43 -0000, Dave wrote: > seems strange, and not very practical. There is an element of both I agree and the locomotive environment, except in the newer ones, can be a bit hairy. Whether or not the concept is valid, that's for DHS to decide and they already have. The driving force behind this, imo, is that during NOLA no effort was made to use the RR as a means of evac. Several of the lines offered but FEMA refused. Instead, Carnival made off like a bandit with 1/3 full ships but 3/3 full government pay. In order to evac, the RR would need to run flat out and with an evac traffic surge, crossings become more critical. -- Drop the alphabet for email Article: 218115 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:14:53 -0400 Message-ID: <45xvuwnf0a7u.1l4b30s6qnu8s$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <04i0f.15845$iM2.1296048@news.xtra.co.nz> > "Ari Silversteinn" wrote in message > news:1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net... >> DHS has proposed a change in scenario. They want an on locomotive alerting >> system that could be commandeered and driven at, near or about a disaster >> site. Everything else stays more or less the same, overbroadcasting on >> local AM/FM, power off the locomotive, selective or full frequency >> broadcasting, train (s) to be in motion at all times. 20-30 second >> messages >> that would also combine a message to be aware that a locomotive (at speed) >> will be flying by the at grade crossings. >> >> Comments? On Tue, 4 Oct 2005 11:15:23 +1300, Ken Taylor wrote: > Impractical, for the same reasons cited earlier. What's wrong with > electronic message boards on trailers fitted with sirens and, if deemed > necessarily, a very large guy with a gun to maintain interest. Nothing but why not broadcast an alert that a locomotive, especially at unmarked crossings, is approaching and too supplement other warning systems? > You may find that sci.electronic.misc or sci.electronic.design may be more > relevant, since it's commercial/military and not amateur. Mind you, they may > also be less polite..... > > Ken Thanks, Ken. Should I be scared? -- Drop the alphabet for email Article: 218116 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:16:08 -0400 Message-ID: <1qb4l77ysiert.1trkdkytzr9gi$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Mon, 03 Oct 2005 23:16:33 GMT, kashe@sonic.net wrote: > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn > wrote: > >>DHS has proposed a change in scenario. They want an on locomotive alerting >>system that could be commandeered and driven at, near or about a disaster >>site. Everything else stays more or less the same, overbroadcasting on >>local AM/FM, power off the locomotive, selective or full frequency >>broadcasting, train (s) to be in motion at all times. 20-30 second messages >>that would also combine a message to be aware that a locomotive (at speed) >>will be flying by the at grade crossings. >> >>Comments? > > Tracks across Lake Ponchartrain fell in. After Katrine/Rita, yes, not before. > Granted they were put back in service faster than anything the > government had connection to. I was there for a few days, didn't keep up with that. -- Drop the alphabet for email Article: 218117 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:17:22 -0400 Message-ID: <26p4pwngriu$.c1lcyc4iufja$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Tue, 4 Oct 2005 12:29:52 +1300, Ken Taylor wrote: > Why a loco anyway? It would appear to be the mistaken assumption that > anything that big must have power to burn on anything plugged in by a user. > Not the case - the power from a loco is, not surprisingly, applied to the > tracks. The electric generators used for powering gear other than the > train's vitals are not high power. Locomotive because of the need for a manual override by the Head Engineer. CSX claims they can provide access to 1,000 watts. -- Drop the alphabet for email Article: 218118 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:19:49 -0400 Message-ID: <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> On Tue, 4 Oct 2005 13:03:57 +1300, Ken Taylor wrote: > Well, he's not a troll in that he's making it up as he goes - it appears he > really is hoping to do for his company what he says (source: Google). I have a clear history for anyone to Google. > However it's a job which really equates to: > > > > Not too much wrong with that synopsis, Ken. > A valid way of doing business, but still a crock. > > Ken Indeed it is both. Considering we gave away a central DB technology to DHS-NOLA, then they failed to use it, we are hoping to make money this time around *and* that they will get their acts together. -- Drop the alphabet for email Article: 218119 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:21:41 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Tue, 04 Oct 2005 09:51:46 GMT, kashe@sonic.net wrote: >>> Tracks across Lake Ponchartrain fell in. >>> >>> Granted they were put back in service faster than anything the >>> government had connection to. >> >>Why a loco anyway? It would appear to be the mistaken assumption that >>anything that big must have power to burn on anything plugged in by a user. >>Not the case - the power from a loco is, not surprisingly, applied to the >>tracks. > > Actually, it's not. > > What made you bring up tracks anyway -- my reference to the > tracks on the lake falling in? My point was that the locomotive is > going nowhere there aren't usable tracks. > > On a diesel-electric locomotive, the generator's output is > applied, not to the tracks as you seem to think, but rather through > control circuitry to the stator around the axle. It's rather amusing > to see a repair yard worker with a set of wheels-and-axle (they're all > one single piece, in case you didn't know) clamp a stator around the > axle, connect a battery with a pair of short jumper cables and walk > the whole arrangement across a concrete floor as though he were > walking the family dog. > > BTW, at 4,000+ horsepower, you could plug in nearly anything a > user might want, given proper appliances and the right plug. :-) This is what we have been led to believe and the schematics are on their way in. Jeez, if we can't find wattage on these beasts......... -- Drop the alphabet for email Article: 218120 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:22:40 -0400 Message-ID: <1irobe4fi0gn0.1dmiiddo7a6hi.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com> <4341f644$0$22741$afc38c87@news.optusnet.com.au> On Tue, 4 Oct 2005 13:26:05 +1000, John Doe wrote: > But Wait, > There's more! > Emergency Messaging, over broadcasting on > AM/FM/SCA/IBOC/Satellite/TV/HDTV/Mobile Phone/ Actually, this has been accomplished. -- Drop the alphabet for email Article: 218121 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:24:48 -0400 Message-ID: <11akczykn6y9h$.1b96w6z2bkox.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <497c5$4341de9e$97d558d8$12886@ALLTEL.NET> On Mon, 3 Oct 2005 21:44:09 -0400, Fred W4JLE wrote: > That would be much easier, simply sweep a modulated oscillator across the > band. With a couple of adjustments it would be easy to emulate a train > whistle, a somewhat universal warning. That's a better idea than a tone and what has been proposed is a tone and an electronic pre-recorded message. Thanks. -- Drop the alphabet for email Article: 218122 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:27:44 -0400 Message-ID: <1gpauygr8vwj8$.w2r0e8ab7h9a$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On 4 Oct 2005 14:12:19 GMT, Allodoxaphobia wrote: > On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn wrote: >> DHS has proposed a change in scenario. They want an on locomotive alerting >> system that could be commandeered and driven at, near or about a disaster >> site. Everything else stays more or less the same, overbroadcasting on >> local AM/FM, power off the locomotive, selective or full frequency >> broadcasting, train (s) to be in motion at all times. 20-30 second messages >> that would also combine a message to be aware that a locomotive (at speed) >> will be flying by the at grade crossings. >> >> Comments? > > And what are these messages suppose to convey? Primarily two things, alerting pre-evac and at grade crossing alerts that a high speed locomotive is approaching. > We all (outside the screwed zone) saw the blizzard of useless > "messages" the government(s) issued during and after Katrina. And a blizzard of useful ones as well. -- Drop the alphabet for email Article: 218123 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:30:02 -0400 Message-ID: <1vxmfnl5tqwf4$.uu9c4c3tmrt0.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> > "Ari Silversteinn" wrote in message > news:c9gqhrx7nggh$.1hmwsp16r4gsh.dlg@40tude.net... >> On Mon, 3 Oct 2005 12:01:14 -0400, Fred W4JLE wrote: >> >>> In that case, simply modify the sign to "Tune to 560, it could save your >>> life" and use a discrete frequency low power transmitter. >> >> I assume you mean to take up an unused local channel? Or to bargain for >> time on a used one? >> >> Both ideas make sense. >> -- >> Drop the alphabet for email On Mon, 3 Oct 2005 21:47:29 -0000, Dave wrote: > if this is for real time notification you don't have time to bargain or to > find an unused channel... and who would listen to you anyway if it was > unused? how often do you turn the knob on your car radio?? Often actually and I agree about the unused channel, at first blush > what about the emergency broadcast system? that would seem to be the > 'proper' method of emergency notification, its already set up for all sorts > of local, regional, and national notifications. The EBS is voluntary, this is not. -- Drop the alphabet for email Article: 218124 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:31:14 -0400 Message-ID: <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> On Mon, 3 Oct 2005 17:58:33 -0400, Fred W4JLE wrote: > There are a couple of frequiencies for unlicensed low power am stations. You > can see them in use by real estate folks selling houses. There are no > commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. -- Drop the alphabet for email Article: 218125 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:33:14 -0400 Message-ID: <1nsajgzh7rq53$.n9o16txa4x4a$.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <11k3dmkqbnho149@corp.supernews.com> >> Excellent point, in my research I saw this handoff or spectrum management >> authority of the DoD and it makes sense. This is a serious, additional >> consideration and is all the more reason to get the DHS' blessings. >> >> Thanks. On Mon, 03 Oct 2005 17:55:13 -0500, David G. Nagel wrote: > Actually the DOD does not have any authority over radio spectrum. There > are two federal agencies that do. One is the FCC, which we all know and > love, the other is NTIA, the National Telecomunications Information > Agency. NITA controls all federal radio frequencies. Since the DOD is a > Federal Agency their frequencies are controled by NTIA the same as the > FBI, CIA Secret Service, Dept of Homeland Security and any other federal > alphabet soup agency. > > Dave N > a FCC and a NTIA user Know of the NTIA but I believe that what is the reality is that the mil gets first dibs on frequencies, then hands off the rest and in a state of national emerg, they can pretty much takeover the airwaves. -- Drop the alphabet for email Article: 218126 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:37:22 -0400 Message-ID: References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128390761.510351.170710@g43g2000cwa.googlegroups.com> Hi Ari I always wonder whether broadcast at the most common IF frequencies would be a viable alternative? (eg 455khz for AM) Legality issues aside of course... This would make frequency selection a little easier to engineer. You wouldnt have to divide your power budget into many operating frequencies as well. Problem is that you'd need a lot higher ERP especially since car mounted radios tend to be better shielded than portables. (You'll need to experiment some) On 3 Oct 2005 18:52:41 -0700, hhc314@yahoo.com wrote: > Wonder no longer, because broadcasing at IF frequencies has been for > year the standard in the US. In spite of some rather silly speculative > posts, this mechanism has proved itself for more than 10-years here. > > In a confined space such as a tunnel, a transmitter of 10-watts more > than sufficint to get the job done, and using nothing more > sophisticated than a simple wire radiator running the length of the > tunnel. > > In Boston, we also retransmit commercial radio broadcasts into our > tunnels, but that requires equipment dedicated to each radio channel > that we re-broadcast, and that becomes very costly after 10 stations or > so, hence there is a limit. > > The real challenge is in maintaining emergency communications to the > outside from within our tunnels. All are serviced by the traditional > leaky coax that runs along the top of the tunnel, but considering that > all of these emergency services operate on their own indepdendent > frequency bands, so servicing them simulteously becomes somwhat > problematic. particularly when hand-held, low power devices enter the > big picture. > > Harry C. Problematic? That would be an understatement. -- Drop the alphabet for email Article: 218127 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:38:04 -0400 Message-ID: References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128390761.510351.170710@g43g2000cwa.googlegroups.com> On Tue, 4 Oct 2005 14:57:01 +1300, Ken Taylor wrote: > All agreed, but that is in a tunnel, which has the advantage of not having > to overcome the still-received commercial stations. The OP wants to do this > out in the open, anywhere, any time. He also wanted to do it while driving > at high speed for some reason, but I think he's quietly shelved that part of > the idea. > > Cheers. > > Ken MOF, it has reared its ugly hi speed head again. -- Drop the alphabet for email Article: 218128 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:38:44 -0400 Message-ID: <1qf1chehdlfrr.ermviox2lja1$.dlg@40tude.net> References: <3po2k11ti506b359m27i8np3cun993i26u@4ax.com> <1lb9rnabij6q8.1qdlbba6ct3dh.dlg@40tude.net> On Mon, 03 Oct 2005 14:31:36 -0700, Richard Clark wrote: > On Mon, 3 Oct 2005 16:33:52 -0400, Ari Silversteinn > wrote: >>OK, so we supply the amplification. > > OK, this is just a re-run of previous speculations. You don't know > the depth of your energy budget crisis, do you? Open coffers. -- Drop the alphabet for email Article: 218129 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:51:50 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com> <4341f644$0$22741$afc38c87@news.optusnet.com.au> <434296fe$0$29450$afc38c87@news.optusnet.com.au> On Wed, 5 Oct 2005 00:51:49 +1000, John Doe wrote: > Durrrrrr, > Can anyone spell EAS > http://www.fcc.gov/eb/eas/ The EAS is designed to provide the President with a means to address the American people in the event of a national emergency. -- Drop the alphabet for email Article: 218130 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 11:52:53 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Tue, 04 Oct 2005 14:33:52 GMT, Wayne P. Muckleroy wrote: > Like I said in another thread, "Emergency" implies IMMEDIATE (not planned) > danger to life, limb, or property. It seems that, in your proposal, you are > PLANNING to use these frequencies instead of more appropriate ones. I would > think that you need to create (and supply) a system that is isolated from > broadcast frequencies. > > Wayne- > (KC8UIO) It's not my call, Wayne, it's the client driving the systems. -- Drop the alphabet for email Article: 218131 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 11:54:30 -0400 Message-ID: <1mf7yuoy4k570$.nphmoya17pjw$.dlg@40tude.net> References: On Tue, 04 Oct 2005 14:54:42 GMT, Wayne P. Muckleroy wrote: > Suggestion: Why don't you also broadcast such "emergency" information over > the entire spectrum of wireless network frequencies? That way, you could > post the information into every Usenet group on the globe. Just like you > have done with these postings. Usenet being a place that only a few people access, aside from that, it's not a bad idea, actually. -- Drop the alphabet for email Article: 218132 of rec.radio.amateur.antenna From: "Caveat Lector" References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> <11k56fd3oubmsf6@corp.supernews.com> Subject: Re: Military Radio Question Message-ID: Date: Tue, 4 Oct 2005 09:31:26 -0700 Since it is a Nicad -- why not use a 13.5 volt power supply with a constant current regulator chip ?? Check National's chips with google -- CL -- I doubt, therefore I might be ! "Rod Maupin" wrote in message news:11k56fd3oubmsf6@corp.supernews.com... > The PRC-1099 manual just says what type of battery to use. When I bought > the radio, the battery came with it. > > Actually, I was incorrect. The manual was talking about using different > battery types, lead-calcium being one of them, but on the battery it has > the following information: > > On the side > ------------ > Battery, Rechargeable BB-586/U > Nickel Cadmium, Sealed > 13.2 Volts, 4.0 Ampere Hours > At 0.8 Ampere > Bren-Tronics, Inc. > Commack, New York > > On the top > ----------- > Charging Instructions > Recommended charge rate is 1 AMP for 5 to 6 hours. Charging temperature > should be 40 deg. F. to 90 deg. F. > > > Thanks for the help, > > Rod KI7CQ > > > > Article: 218133 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> Subject: Re: Military Radio Question Date: Tue, 4 Oct 2005 13:20:05 -0400 Message-ID: <355bc$4342b9fb$97d558d8$8735@ALLTEL.NET> You might want to point out that if you do not modify the Aston, such practice will cause a problem with in the Aston. "Cecil Moore" wrote in message news:obw0f.356$dB4.26@newssvr12.news.prodigy.com... > Jerry Martes wrote: > > If the battery terminal voltage is restricted to being no higher than 14.8 > > volts,the battery will not boil off its electrolyte. > > I float my deep-discharge marine backup battery on my Astron > 13.6 vdc power supply. If AC fails, I hardly notice it. > -- > 73, Cecil, http://www.qsl.net/w5dxp Article: 218134 of rec.radio.amateur.antenna From: "Jerry Martes" References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> Subject: Re: Military Radio Question Message-ID: Date: Tue, 04 Oct 2005 17:47:51 GMT Hi Chuck Yeah, the wall warts are marked with output voltages that are only approximate. The real test of the wall wart would require that it be hooked up to charge a capacitor. That will indicate the maximum voltage to which the battery will charge. The average Lead-Acid, Calcium, 12 volt battery will require about 14.8 volts to begin boiling out its electrolyte. Charging batteries might not be "rocket science", but it can get complicated. There is so much good info available on the Internet that it would be wrong of me to pretend that I'm an expert only because I understand a little about the subject. A wall wart, marked as about 9 or 10 volts DC with a 12 volt bulb in series with it, can be used as a decent float charger. I'll assume that anyone reading this group will see the technology behind this low cost, readily available system. Jerry "chuck" wrote in message news:J1u0f.7942$vw6.5655@newsread1.news.atl.earthlink.net... > Jerry, > > The 10 volt DC wall wart is unfiltered and the designated voltage is 10 > vdc rms? So it would be supplying 14.1 volts peak? > > Trying to understand how the 10 volt supply will charge a 12 volt battery. > > Thanks. > > Chuck > > Jerry Martes wrote: >> "Rod Maupin" wrote in message >> news:11k3j0s7dujl92a@corp.supernews.com... >> >>>I posted this on another group, but you all seem really smart here. >>> >>>I have a military radio (PRC-1099) and a battery. I want to buy a power >>>supply that will power the radio but which can also be used to charge the >>>battery. The radio needs a 12V power supply to run. The battery is a >>>lead-calcium type, and is supposed to be charged at 1A for 5 to 6 hours. >>> >>>Buying a 12V power supply is easy, but do supplies normally have a >>>variable current output? I am not an authority on power supplies or >>>charging batteries, so I need some help here. >>> >>>Thanks, >>> >>>Rod KI7CQ >> >> >> Rod >> >> For what reason is it needed to require the battery to be charged >> within 6 hours? If it is practical to charge the battery "overnight", >> the requirements could be much less expensive. >> There is alot-alot of information on the Internet about charging >> lead-acid batteries. The lead-Calcium is the type cell commonly used in >> most automotive autos today. >> If this was my radio, I'd use a wall wart with a 12 volt lamp in series >> between the wall wart and the battery. . A 10 volt DC, 1 amp wall wart >> would probably be close to proper for this radio. The series lamp will >> limit the charge rate. >> >> If the battery terminal voltage is restricted to being no higher than >> 14.8 volts,the battery will not boil off its electrolyte. >> >> Jerry >> Article: 218135 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Military Radio Question References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> <355bc$4342b9fb$97d558d8$8735@ALLTEL.NET> Message-ID: Date: Tue, 04 Oct 2005 18:13:31 GMT Fred W4JLE wrote: > You might want to point out that if you do not modify the Aston, such > practice will cause a problem with in the Aston. Thanks Fred, I didn't modify the Astron but it and my solar panel are ORed into the battery through big Schottky diodes. -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218136 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> <355bc$4342b9fb$97d558d8$8735@ALLTEL.NET> Subject: Re: Military Radio Question Date: Tue, 4 Oct 2005 14:30:48 -0400 Message-ID: The 723 in the Astron will eventually fry when you remove AC power. A simple fix is off of pin 4 that normally goes to the wiper of the voltage adjustment, cut the land and bridge with a 10K 1/2 watt resistor. I have probably modified over 50 of them for our EOC sites and have never lost a PS. "Cecil Moore" wrote in message news:fDz0f.726$we3.149@newssvr13.news.prodigy.com... > Fred W4JLE wrote: > > You might want to point out that if you do not modify the Aston, such > > practice will cause a problem with in the Aston. > > Thanks Fred, I didn't modify the Astron but it and my solar > panel are ORed into the battery through big Schottky diodes. > -- > 73, Cecil, http://www.qsl.net/w5dxp Article: 218137 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Military Radio Question References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> <355bc$4342b9fb$97d558d8$8735@ALLTEL.NET> Message-ID: Date: Tue, 04 Oct 2005 18:54:49 GMT Fred W4JLE wrote: > The 723 in the Astron will eventually fry when you remove AC power. Even if it is feeding the battery through a diode? -- 73, Cecil, http://www.qsl.net/w5dxp Article: 218138 of rec.radio.amateur.antenna From: "Ken Taylor" References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128390761.510351.170710@g43g2000cwa.googlegroups.com> Subject: Re: Emergency Messaging And AM Message-ID: <_mA0f.15977$iM2.1314352@news.xtra.co.nz> Date: Wed, 5 Oct 2005 08:04:25 +1300 "Ari Silversteinn" wrote in message news:gtj6zf6ou3fv.s2rsv1mhe6kr$.dlg@40tude.net... > On Tue, 4 Oct 2005 14:57:01 +1300, Ken Taylor wrote: > >> All agreed, but that is in a tunnel, which has the advantage of not >> having >> to overcome the still-received commercial stations. The OP wants to do >> this >> out in the open, anywhere, any time. He also wanted to do it while >> driving >> at high speed for some reason, but I think he's quietly shelved that part >> of >> the idea. >> >> Cheers. >> >> Ken > > MOF, it has reared its ugly hi speed head again. > -- Sorry, what's 'MOF'? Ken Article: 218139 of rec.radio.amateur.antenna From: "Ken Taylor" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> Subject: Re: Emergency Messaging And AM Message-ID: <1qA0f.15978$iM2.1314092@news.xtra.co.nz> Date: Wed, 5 Oct 2005 08:07:40 +1300 "Ari Silversteinn" wrote in message news:1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net... > On Mon, 3 Oct 2005 17:58:33 -0400, Fred W4JLE wrote: > >> There are a couple of frequiencies for unlicensed low power am stations. >> You >> can see them in use by real estate folks selling houses. There are no >> commercial stations on the frequency. > > Yes, and at Disney World, etc. This is a very doable idea and may well > solve FCC/DoD issues. > -- When was the last time you listened to one of those frequencies? It won't get the message out where it's needed. Ken Article: 218140 of rec.radio.amateur.antenna From: "Ken Taylor" References: <3po2k11ti506b359m27i8np3cun993i26u@4ax.com> <1lb9rnabij6q8.1qdlbba6ct3dh.dlg@40tude.net> <1qf1chehdlfrr.ermviox2lja1$.dlg@40tude.net> Subject: Re: Emergency Messaging And AM Message-ID: Date: Wed, 5 Oct 2005 08:09:19 +1300 "Ari Silversteinn" wrote in message news:1qf1chehdlfrr.ermviox2lja1$.dlg@40tude.net... > On Mon, 03 Oct 2005 14:31:36 -0700, Richard Clark wrote: > >> On Mon, 3 Oct 2005 16:33:52 -0400, Ari Silversteinn >> wrote: >>>OK, so we supply the amplification. >> >> OK, this is just a re-run of previous speculations. You don't know >> the depth of your energy budget crisis, do you? > > Open coffers. > > -- He wasn't referring to your finance budget, but your energy budget. I hesitate to say it can't be done in any practical sense, but that's my thought. The idea of one poster to transmit on the IF's is a good one but I didn't suggest that because you'll also kill your emergency services comm's. Incidentally, do you plan to have every loco in the US fitted out or are you going to fly the loco's to the incident site to do their stuff? Cheers. Ken Article: 218141 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Wed, 5 Oct 2005 08:12:56 +1300 "Ari Silversteinn" wrote in message news:mah7mjs7s37w.18ed2dgq49p30.dlg@40tude.net... > On Tue, 04 Oct 2005 14:33:52 GMT, Wayne P. Muckleroy wrote: > >> Like I said in another thread, "Emergency" implies IMMEDIATE (not >> planned) >> danger to life, limb, or property. It seems that, in your proposal, you >> are >> PLANNING to use these frequencies instead of more appropriate ones. I >> would >> think that you need to create (and supply) a system that is isolated from >> broadcast frequencies. >> >> Wayne- >> (KC8UIO) > > It's not my call, Wayne, it's the client driving the systems. > -- But you've already changed it! Initially you said it was to be used at an emergency site, and now you're saying it's to warn of a high-speed train cometh. What the hell gives? Ken Article: 218142 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Wed, 5 Oct 2005 08:15:24 +1300 wrote in message news:aoi4k1l3cj86fg3vjnadnmepbcvvj8anjg@4ax.com... > On Tue, 4 Oct 2005 12:29:52 +1300, "Ken Taylor" > wrote: > >> wrote in message >>news:mre3k15n9721h4kt0bmr019vvosggdohlp@4ax.com... >>> On Mon, 3 Oct 2005 17:19:42 -0400, Ari Silversteinn >>> wrote: >>> >>>>DHS has proposed a change in scenario. They want an on locomotive >>>>alerting >>>>system that could be commandeered and driven at, near or about a >>>>disaster >>>>site. Everything else stays more or less the same, overbroadcasting on >>>>local AM/FM, power off the locomotive, selective or full frequency >>>>broadcasting, train (s) to be in motion at all times. 20-30 second >>>>messages >>>>that would also combine a message to be aware that a locomotive (at >>>>speed) >>>>will be flying by the at grade crossings. >>>> >>>>Comments? >>> >>> Tracks across Lake Ponchartrain fell in. >>> >>> Granted they were put back in service faster than anything the >>> government had connection to. >> >>Why a loco anyway? It would appear to be the mistaken assumption that >>anything that big must have power to burn on anything plugged in by a >>user. >>Not the case - the power from a loco is, not surprisingly, applied to the >>tracks. > > Actually, it's not. > > What made you bring up tracks anyway -- my reference to the > tracks on the lake falling in? My point was that the locomotive is > going nowhere there aren't usable tracks. > > On a diesel-electric locomotive, the generator's output is > applied, not to the tracks as you seem to think, but rather through > control circuitry to the stator around the axle. It's rather amusing > to see a repair yard worker with a set of wheels-and-axle (they're all > one single piece, in case you didn't know) clamp a stator around the > axle, connect a battery with a pair of short jumper cables and walk > the whole arrangement across a concrete floor as though he were > walking the family dog. > > BTW, at 4,000+ horsepower, you could plug in nearly anything a > user might want, given proper appliances and the right plug. :-) > > > >> The electric generators used for powering gear other than the >>train's vitals are not high power. >> >>Ken >> 4,000hp is a lot but not enough to swamp all the broadcast radios, which is what the OP wants. Incidentally my reference to tracks was just that the loco is made to move, not power a boom-box. Like your anecdote though. :-) Cheers. Ken Article: 218143 of rec.radio.amateur.antenna From: "RST Engineering" Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 12:17:17 -0700 Message-ID: <11k5l9tnld8mp85@corp.supernews.com> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> I can't find the part of the FCC regs that provide these frequencies for unlicensed stations. Can anybody share the chapter and verse? Jim >>> There are a couple of frequiencies for unlicensed low power am stations. >>> You >>> can see them in use by real estate folks selling houses. There are no >>> commercial stations on the frequency. >> >> Yes, and at Disney World, etc. This is a very doable idea and may well >> solve FCC/DoD issues. Article: 218144 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <04i0f.15845$iM2.1296048@news.xtra.co.nz> <45xvuwnf0a7u.1l4b30s6qnu8s$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Wed, 5 Oct 2005 08:19:05 +1300 "Ari Silversteinn" wrote in message news:45xvuwnf0a7u.1l4b30s6qnu8s$.dlg@40tude.net... > > >> "Ari Silversteinn" wrote in message >> news:1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net... >>> DHS has proposed a change in scenario. They want an on locomotive >>> alerting >>> system that could be commandeered and driven at, near or about a >>> disaster >>> site. Everything else stays more or less the same, overbroadcasting on >>> local AM/FM, power off the locomotive, selective or full frequency >>> broadcasting, train (s) to be in motion at all times. 20-30 second >>> messages >>> that would also combine a message to be aware that a locomotive (at >>> speed) >>> will be flying by the at grade crossings. >>> >>> Comments? > > On Tue, 4 Oct 2005 11:15:23 +1300, Ken Taylor wrote: > >> Impractical, for the same reasons cited earlier. What's wrong with >> electronic message boards on trailers fitted with sirens and, if deemed >> necessarily, a very large guy with a gun to maintain interest. > > Nothing but why not broadcast an alert that a locomotive, especially at > unmarked crossings, is approaching and too supplement other warning > systems? > >> You may find that sci.electronic.misc or sci.electronic.design may be >> more >> relevant, since it's commercial/military and not amateur. Mind you, they >> may >> also be less polite..... >> >> Ken > > Thanks, Ken. > > Should I be scared? > -- No, but forewarned is fore armed. :-) Your spec's are a bit nebulous, to say the least. I'm not accusing you of having no clue, but I'm damn glad DHS doesn't use tax-payer funds from this part of the world. This is an exercise in getting rid of funds grabbed during a crisis, when the opportunity arose to expand the empire. Standard bureaucratic function. Cheers. Ken Article: 218145 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Wed, 5 Oct 2005 08:26:12 +1300 "Ari Silversteinn" wrote in message news:1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net... > On Tue, 4 Oct 2005 13:03:57 +1300, Ken Taylor wrote: > >> Well, he's not a troll in that he's making it up as he goes - it appears >> he >> really is hoping to do for his company what he says (source: Google). > > I have a clear history for anyone to Google. > Sure do, I was pointing that out. Hence I don't think you're a troll. >> However it's a job which really equates to: >> >> >> >> > commences> > > Not too much wrong with that synopsis, Ken. > >> A valid way of doing business, but still a crock. >> >> Ken > > Indeed it is both. Considering we gave away a central DB technology to > DHS-NOLA, then they failed to use it, we are hoping to make money this > time > around *and* that they will get their acts together. > -- I'm really not criticizing you, per se, but I don't think the concept is well thought out. You refer elsewhere to this being an auxiliary warning system on a loco - level crossing lights/bells/boom gates not enough? They usually are, so why the worry now? (Okay, we know it's the moolah....). You also refer to 1,000W being available - it's just not enough for what you want to do. Period. Good luck with them getting their act (I would have said something else!) together, but don't bet the bank on it. I'm actually an ex-bureaucrat myself and to call me cynical of governmental abilities would be an understatement. But if you do come up with something useful (I bet it ends up being a spin-off rather than the initial concept seen here), I hope you get something out of it. Cheers. Ken Article: 218146 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <11k3j0s7dujl92a@corp.supernews.com> <5Ao0f.223$yN6.23@trnddc04> <355bc$4342b9fb$97d558d8$8735@ALLTEL.NET> Subject: Re: Military Radio Question Date: Tue, 4 Oct 2005 16:03:43 -0400 Message-ID: <820b5$4342e055$97d558d8$25308@ALLTEL.NET> No, but then again you can save the cost of the diodes and the associated voltage drop when operating from the power supply. My concern was that someone with less knowledge than yourself would simply parallel the battery with the Astron power supply. Your initial message did not have a caveat for those that thought it might be that simple. "Cecil Moore" wrote in message news:ZdA0f.8755$oO2.4492@newssvr27.news.prodigy.net... > Fred W4JLE wrote: > > The 723 in the Astron will eventually fry when you remove AC power. > > Even if it is feeding the battery through a diode? > -- > 73, Cecil, http://www.qsl.net/w5dxp Article: 218147 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 16:09:19 -0400 Message-ID: It can be found under the section that allows a transmitter as long as it is less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. "RST Engineering" wrote in message news:11k5l9tnld8mp85@corp.supernews.com... > I can't find the part of the FCC regs that provide these frequencies for > unlicensed stations. Can anybody share the chapter and verse? > > Jim > > > >>> There are a couple of frequiencies for unlicensed low power am stations. > >>> You > >>> can see them in use by real estate folks selling houses. There are no > >>> commercial stations on the frequency. > >> > >> Yes, and at Disney World, etc. This is a very doable idea and may well > >> solve FCC/DoD issues. > > Article: 218148 of rec.radio.amateur.antenna From: "RST Engineering" Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 13:51:06 -0700 Message-ID: <11k5qprf314vs63@corp.supernews.com> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> That is part 15 and it isn't just a couple of frequencies, it is any frequency in the AM broadcast band (and the FM broadcast band, for that matter). Specifically, 15.219 allows operation on any frequency in the band so long as (a) the input power to the final stage is less than 100 mW and (b) the antenna "system" (radiating element, coax, and ground lead) is less than 3 meters long. 15.221 also allows operation with an unspecified power level into leaky coax with a field strength limitation. Power is not milliwatts per meter. Power is milliwatts. Field strength (also an allowed measurement) is in volts per meter. The OP said that there were a "couple of frequiencies(sic)for unlicensed low power am(sic) stations." That implied that there were a couple of frequencies that were unused in the AM band by commercial stations, and I just wanted to have a reference to WHAT they were and WHERE in the regs they were delineated. Jim "Fred W4JLE" wrote in message news:effaf$4342e1a5$97d558d8$26195@ALLTEL.NET... > It can be found under the section that allows a transmitter as long as it > is > less than some number of milliwatts per meter. > > If you really need the exact section, I will drag out the regs and get it > for you. > > "RST Engineering" wrote in message > news:11k5l9tnld8mp85@corp.supernews.com... >> I can't find the part of the FCC regs that provide these frequencies for >> unlicensed stations. Can anybody share the chapter and verse? >> >> Jim >> >> >> >>> There are a couple of frequiencies for unlicensed low power am > stations. >> >>> You >> >>> can see them in use by real estate folks selling houses. There are no >> >>> commercial stations on the frequency. >> >> >> >> Yes, and at Disney World, etc. This is a very doable idea and may well >> >> solve FCC/DoD issues. >> >> > > Article: 218149 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 17:31:37 -0400 Message-ID: <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> In this case the milliwatts per meter refers to frequencies stated in meters. Volts per meter only applies to the E component, the magnetic component is always stated in amps per meter. I will get back to you on the specifics. I am pretty sure that my brain is not suffering from a senior moment as to my recollection of the regs. "RST Engineering" wrote in message news:11k5qprf314vs63@corp.supernews.com... > Power is not milliwatts per meter. Power is milliwatts. Field strength > (also an allowed measurement) is in volts per meter. > Article: 218150 of rec.radio.amateur.antenna From: "Crazy George" References: <43422d26$1@news.wineasy.se> Subject: Re: Connecting several bandpass filters. Date: Tue, 4 Oct 2005 16:46:07 -0500 Message-ID: <4342fba9_3@news1.prserv.net> Ben Jackson has some good points. You need not worry about audio, usually, as the FM capture takes care of the weaker signal. So, filtering the video carrier and near sidebands is all that is necessary. However, in answer to your question, the way you connect bandpass filters in parallel is with power dividers, amplifiers, and power dividers again, backwards as summers. Otherwise, controlling the out of band input and output impedances of several in parallel is a monumental, but solvable task. Spice, anyone? -- Crazy George "SH" wrote in message news:43422d26$1@news.wineasy.se... > Hi > > I have come up with one of those crazy DYI ideas which I would like to try > to implement but one thing still remains. > > I have two UHF (TV) arial pointing in different directions and would like to > connect them together through BP filters to minimize noise. > BP = Bandpass > Antenna 1: UHF channel (Europe) BP 1 ch 22-37, BP 2 ch40 -44, BP 3 ch 49 - > 68/ or high pass > Antenna 2: UHF channel (Europe) BP 1 ch 21 / or low pass, BP 2 ch38 -39, BP > 3 ch 47 > > I have found formulas to design each section of BF but how to you connect > several BP filters in parallel??? I have investigated some old TV filter and > they have a coil (12 WDG) in and out of each BP section but is that the way > to do it and how does it influence the design of each BP. > > The only approach that I can find is to split the signal into three (- 6dB ) > then feed each into a BP filter and the Combine them again (-6dB). This will > result in each BP section seeing 75 Ohms as they shouland they would not > interfere with eachother. Ofcouse i would need a 20 dB amplifier to fix the > loss. > > But is there a better way. > > Best regards > > Svend Holby > > Article: 218151 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: Lightning Question Date: Tue, 4 Oct 2005 16:17:17 -0500 Message-ID: References: "Asimov" wrote in message news:MSGID_1=3a167=2f133.0_433e12e6@fidonet.org... > "Steve Nosko" bravely wrote to "All" (30 Sep 05 16:59:44) > --- on the heady topic of "Re: Lightning Question" > > SN> From: "Steve Nosko" > SN> Xref: core-easynews rec.radio.amateur.antenna:217792 > > SN> "...alternative to the lightning rod. ..." > SN> Their purpose it to bleed off the charge so it can't develop to the > SN> point where the leaders can start and prevent the strike. You need to > SN> get the charge out of there, not let it continue to build until it > SN> finds another path it can breach. Charge concentrates at a point and > SN> low level ionization bleeds off the charge "safely". > > SN> You put large round balls on static generators so that you DO allow > SN> the charge to build up and not bleed off. > > So then why does the lightning prefer to hit the rod? I've seen > St-Elmo's fire on a metal chimney, quite interesting. \ Does it? Is that what actually happens? Perhaps people aren't keeping them properly maintained. That's why I have started the very first Lighting rod maitenance technician shcool. I'll publish the info as soon as we get the web site up. 73, Steve, K9DCi > A*s*i*m*o*v > > ... Birthdays are good for you - the more you have the longer you live. > Article: 218152 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 17:57:10 -0400 Message-ID: <7bf3f$4342faef$97d558d8$24062@ALLTEL.NET> Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. There are certain bands that no emissions are allowed from a low powered device. For example setting up your neighborhood micro Rap Station on 121.5 MHz (aircraft emergency) would probably bring a swift shut down. I am still searching for the reg that allows fixed information stations. IIRC they can be run on 530 and 1750 KHz. I know in the past I had looked at the regs and the particular station I was researching was indeed legal. In the low freqs (140 KHz area) you can run up to 1 watt CW with out a license. "Richard Clark" wrote in message news:2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com... > On Tue, 4 Oct 2005 17:31:37 -0400, "Fred W4JLE" > wrote: > >In this case the milliwatts per meter refers to frequencies stated in > >meters. > > Hi Fred, > > Is this to suggest that for 300MHz it is 1mW total input power as say > compared to 1MHz allowing 300mW? > > This would be uncharacteristically generous of the FCC whose > regulations would ban emissions from dummy loads. > > Seems it would hardly serve Ari's search for pork, but I suppose > grantsmanship would jump at sending a marathon of runners through the > spill area - each carrying sub-Watt handi-talkies to provide the > aggregate power, and spectrum, and lung volume necessary to "get the > warning out." > > 73's > Richard Clark, KB7QHC Article: 218153 of rec.radio.amateur.antenna From: "RST Engineering" Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 15:09:50 -0700 Message-ID: <11k5vdfh3t5jt29@corp.supernews.com> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> <7bf3f$4342faef$97d558d8$24062@ALLTEL.NET> Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message news:7bf3f$4342faef$97d558d8$24062@ALLTEL.NET... > Richard the value changes per band and is stated in part 15. For example > in > the broadcast band the formula is 24000 /F for microvolts at 1000 feet. Article: 218154 of rec.radio.amateur.antenna From: "Steve Nosko" Subject: Re: Lightning Question Date: Tue, 4 Oct 2005 16:19:32 -0500 Message-ID: References: <13320-433E780E-161@storefull-3255.bay.webtv.net> "Richard Harrison" wrote in message news:13320-433E780E-161@storefull-3255.bay.webtv.net... > Asimov wrote: > "So then why does the lightning prefer to hit the rod?" > > The rod is salient. > > It`s the voltage gradient, which is not a uniform function of position > or altirude, but is greater at sharp edges and points. These initiate > ionozarion which precipitates lightning. > > Best regards, Richard Harrison, KB5WZI > So... They're not effective in bleeding off the charge? Maybe I'll have to refund those tuitions. 73, Steve, K9DCI Article: 218155 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 18:28:16 -0400 Message-ID: <11ta0tcw4oytz.1d6ji7kwpmay9$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <04i0f.15845$iM2.1296048@news.xtra.co.nz> <45xvuwnf0a7u.1l4b30s6qnu8s$.dlg@40tude.net> On Wed, 5 Oct 2005 08:19:05 +1300, Ken Taylor wrote: >> >>> You may find that sci.electronic.misc or sci.electronic.design may be >>> more >>> relevant, since it's commercial/military and not amateur. Mind you, they >>> may >>> also be less polite..... >>> >>> Ken >> >> Thanks, Ken. >> >> Should I be scared? >> -- > No, but forewarned is fore armed. :-) Your spec's are a bit nebulous, to say > the least. I'm not accusing you of having no clue, but I'm damn glad DHS > doesn't use tax-payer funds from this part of the world. This is an exercise > in getting rid of funds grabbed during a crisis, when the opportunity arose > to expand the empire. Standard bureaucratic function. The problem is that anything that is speced at this point is bound to be changed by FEMA, DHS, FCC, and God knows who else. The idea is to start somewhere and march forward beginning with the writing of a "white paper" that can be shot full of holes. -- Drop the alphabet for email Article: 218156 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 18:31:46 -0400 Message-ID: <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> >> Indeed it is both. Considering we gave away a central DB technology to >> DHS-NOLA, then they failed to use it, we are hoping to make money this >> time >> around *and* that they will get their acts together. On Wed, 5 Oct 2005 08:26:12 +1300, Ken Taylor wrote: > I'm really not criticizing you, per se, but I don't think the concept is > well thought out. By it's very nature, it cannot be, it is a dynamically moving target and will be for some time I would imagine. > You refer elsewhere to this being an auxiliary warning system on a loco - > level crossing lights/bells/boom gates not enough? They usually are, so why > the worry now? (Okay, we know it's the moolah....). The number of unmarked or unworkable crossings is greater than the ones quadrant marked and useable. > You also refer to 1,000W being available - it's just not enough for what you > want to do. Period. 3 watts per frequency? > Good luck with them getting their act (I would have said something else!) > together, but don't bet the bank on it. I'm actually an ex-bureaucrat myself > and to call me cynical of governmental abilities would be an understatement. Well, if in the process we get paid, then wtf, you know? > But if you do come up with something useful (I bet it ends up being a > spin-off rather than the initial concept seen here), I hope you get > something out of it. > > Cheers. > > Ken Thanks, Ken, it would be nice to do something that would save lives and limbs and also make a few asspennies :) -- Drop the alphabet for email Article: 218157 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 18:33:00 -0400 Message-ID: <1trzn633vp9a8$.1pn63sxhs5cim$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1gpauygr8vwj8$.w2r0e8ab7h9a$.dlg@40tude.net> <3v3b13-e9a.ln1@fimbul.myth> On Tue, 4 Oct 2005 13:06:27 -0700, Jim Richardson wrote: >> Primarily two things, alerting pre-evac and at grade crossing alerts that a >> high speed locomotive is approaching. >> > > they'd be better off with bells and lights at the crossing for the > latter... Many crossings have none. >>> We all (outside the screwed zone) saw the blizzard of useless >>> "messages" the government(s) issued during and after Katrina. >> >> And a blizzard of useful ones as well. >> > > wheat from chaff? Yep, that's the strategy for now. -- Drop the alphabet for email Article: 218158 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Tue, 4 Oct 2005 18:34:14 -0400 Message-ID: <1b8j1rueikcxv$.lo6nhpwwje4n.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Wed, 5 Oct 2005 08:12:56 +1300, Ken Taylor wrote: >> It's not my call, Wayne, it's the client driving the systems. >> -- > But you've already changed it! Initially you said it was to be used at an > emergency site, and now you're saying it's to warn of a high-speed train > cometh. What the hell gives? > > Ken Both, there are three defined needs (today) 1) on locomotive, permanent at grade crossing and mobile, take-to-site-and-leave. -- Drop the alphabet for email Article: 218159 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:34:59 -0400 Message-ID: <1p9sexua1d9zp.1a94h3pqeexmb$.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> On Wed, 5 Oct 2005 08:07:40 +1300, Ken Taylor wrote: >>> There are a couple of frequiencies for unlicensed low power am stations. >>> You >>> can see them in use by real estate folks selling houses. There are no >>> commercial stations on the frequency. >> >> Yes, and at Disney World, etc. This is a very doable idea and may well >> solve FCC/DoD issues. >> -- > When was the last time you listened to one of those frequencies? It won't > get the message out where it's needed. They suck, I was hoping it was my rental car! -- Drop the alphabet for email Article: 218160 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:35:41 -0400 Message-ID: <8j382mvt6h1u.2u4v4vukhrbk$.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> On Tue, 4 Oct 2005 16:09:19 -0400, Fred W4JLE wrote: > It can be found under the section that allows a transmitter as long as it is > less than some number of milliwatts per meter. > > If you really need the exact section, I will drag out the regs and get it > for you. Does this fall under LPFM/LPAM? -- Drop the alphabet for email Article: 218161 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:37:13 -0400 Message-ID: <1368nf7jyod3d.4njangipsc1j.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> On Tue, 4 Oct 2005 13:51:06 -0700, RST Engineering wrote: > The OP said that there were a "couple of frequiencies(sic)for unlicensed low > power am(sic) stations." That implied that there were a couple of > frequencies that were unused in the AM band by commercial stations, and I > just wanted to have a reference to WHAT they were and WHERE in the regs they > were delineated. > > Jim Truth is, I was thinking about reserved but not yet assigned AM/FM frequencies. -- Drop the alphabet for email Article: 218162 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:38:11 -0400 Message-ID: <15fj9t9a794kl.1j288dmpz9on4$.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> On Tue, 04 Oct 2005 14:46:33 -0700, Richard Clark wrote: > Seems it would hardly serve Ari's search for pork, Hey, I'm Jewish, sort of. -- Drop the alphabet for email Article: 218163 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:39:38 -0400 Message-ID: <10jjkadeqxri6.fg1b0yfm6614.dlg@40tude.net> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> <7bf3f$4342faef$97d558d8$24062@ALLTEL.NET> <11k5vdfh3t5jt29@corp.supernews.com> On Tue, 4 Oct 2005 15:09:50 -0700, RST Engineering wrote: > Not quite. That is the limit in 15.209, with the following caveat > "...except as provided elsewhere in this subpart..." > > Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band > 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction > OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) > meters (which is also lambda/(2 * pi)) from leaky coax. > > BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more > like 100 feet, not 1000 feet (15.209). > > Jim So if I need to go out 3500 feet or so, this won't work. Correct? -- Drop the alphabet for email Article: 218164 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:39:59 -0400 Message-ID: <5nmm9dcylhmw$.1rnrbutgswt22.dlg@40tude.net> References: <3lb613-l4c.ln1@p400bob.personal.cox.net> <1128390761.510351.170710@g43g2000cwa.googlegroups.com> <_mA0f.15977$iM2.1314352@news.xtra.co.nz> On Wed, 5 Oct 2005 08:04:25 +1300, Ken Taylor wrote: >> >> MOF, it has reared its ugly hi speed head again. >> -- > Sorry, what's 'MOF'? Matter of fact..... -- Drop the alphabet for email Article: 218165 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:41:23 -0400 Message-ID: <1vxzpk9xqbmci$.7zy9q225wair.dlg@40tude.net> References: <3po2k11ti506b359m27i8np3cun993i26u@4ax.com> <1lb9rnabij6q8.1qdlbba6ct3dh.dlg@40tude.net> <1qf1chehdlfrr.ermviox2lja1$.dlg@40tude.net> On Wed, 5 Oct 2005 08:09:19 +1300, Ken Taylor wrote: >>> OK, this is just a re-run of previous speculations. You don't know >>> the depth of your energy budget crisis, do you? >> >> Open coffers. >> >> -- > He wasn't referring to your finance budget, but your energy budget. I > hesitate to say it can't be done in any practical sense, but that's my > thought. The idea of one poster to transmit on the IF's is a good one but I > didn't suggest that because you'll also kill your emergency services comm's. lol What;s being tossed around is the ability to allow FEMA et all to kill the ability to transmit and/or we can upon knowing that the emerg comms are in use. > Incidentally, do you plan to have every loco in the US fitted out or are you > going to fly the loco's to the incident site to do their stuff? > > Cheers. > > Ken -- Drop the alphabet for email Article: 218166 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 18:43:45 -0400 Message-ID: <1cbcmu4d514l0.o9jwf977wpd$.dlg@40tude.net> References: <3po2k11ti506b359m27i8np3cun993i26u@4ax.com> <1lb9rnabij6q8.1qdlbba6ct3dh.dlg@40tude.net> <1qf1chehdlfrr.ermviox2lja1$.dlg@40tude.net> On Tue, 04 Oct 2005 12:55:29 -0700, Richard Clark wrote: >>> >>> Open coffers. >>> >>> -- >>He wasn't referring to your finance budget, but your energy budget. I >>hesitate to say it can't be done in any practical sense, but that's my >>thought. > > Hi Ken, > > His terse reply refers to the public coffers - troughs - open for this > fabulous pork barrel feast. You know, crack dealer capitalism. > > Nothing has to actually work, or be useful, or even be used. It just > has to generate paper in one direction, and cash in the other. Ari is > mining us as a dry run for all the terms, shortfalls, and fits to the > jigsaw to rummage up into a proposal. > > 73's > Richard Clark, KB7QHC Considering that we have many technologies in use, mof, all technologies that are not in development are in use, this is a load of horseshit. If we build it to spec, whatever that spec is, it will be proprietary and how and when they use it is not in our hands. -- Drop the alphabet for email Article: 218167 of rec.radio.amateur.antenna From: "RST Engineering" Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 15:46:33 -0700 Message-ID: <11k61iaol82dmb0@corp.supernews.com> References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> <7bf3f$4342faef$97d558d8$24062@ALLTEL.NET> <11k5vdfh3t5jt29@corp.supernews.com> <10jjkadeqxri6.fg1b0yfm6614.dlg@40tude.net> Incorrect. Jim "Ari Silversteinn" wrote in message news:10jjkadeqxri6.fg1b0yfm6614.dlg@40tude.net... >> BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more >> like 100 feet, not 1000 feet (15.209). >> >> Jim > > So if I need to go out 3500 feet or so, this won't work. Correct? > -- > Drop the alphabet for email Article: 218168 of rec.radio.amateur.antenna From: Bob Bob Subject: Re: Balanced from unbalanced via a 100 ohm Q section - followup References: <0au813-9eg.ln1@p400bob.personal.cox.net> Message-ID: <5adb13-isi.ln1@p400bob.personal.cox.net> Date: Tue, 04 Oct 2005 17:45:54 -0500 Hi Jim I actually had a quick look at that for trying to run Ari's 4NEC2 under Linux. Since it calls the DOS shell to run the calc I was hopeful. Cant remember if it worked but was more concerned about how to call it from the GUI under Wine. (ie how to call a Linux pgm from a W32 pgm running under wine!) I tend to use my wife's W98 machine when I need to model things (shame on me!) Many tnxs for your feedback. Cheers Bob Jim Richardson wrote: > > try dosemu instead. Wine won't work well with programs that try to > directly access memory via INTs and such. Article: 218169 of rec.radio.amateur.antenna From: "Fred W4JLE" References: <434071D1.1080009@nettally.com> <1on4ycu9vveeu$.1trf1dy8v6m99.dlg@40tude.net> <94c7c$434155fe$97d558d8$27747@ALLTEL.NET> <1c2ad$4341a9be$97d558d8$20391@ALLTEL.NET> <1bu026rqusoml.l5p3hd8ajkqn.dlg@40tude.net> <1qA0f.15978$iM2.1314092@news.xtra.co.nz> <11k5l9tnld8mp85@corp.supernews.com> <11k5qprf314vs63@corp.supernews.com> <411a6$4342f4f3$97d558d8$4644@ALLTEL.NET> <2et5k1pasuf8p8ue93p3qhfp11bbdmv6ms@4ax.com> <7bf3f$4342faef$97d558d8$24062@ALLTEL.NET> <11k5vdfh3t5jt29@corp.supernews.com> Subject: Re: Emergency Messaging And AM Date: Tue, 4 Oct 2005 19:44:44 -0400 Message-ID: You are correct Jim, mistyped the extra zero. "RST Engineering" wrote in message news:11k5vdfh3t5jt29@corp.supernews.com... > Not quite. That is the limit in 15.209, with the following caveat > "...except as provided elsewhere in this subpart..." > > Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band > 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction > OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) > meters (which is also lambda/(2 * pi)) from leaky coax. > > BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more > like 100 feet, not 1000 feet (15.209). > > > Jim > > > > "Fred W4JLE" wrote in message > news:7bf3f$4342faef$97d558d8$24062@ALLTEL.NET... > > > Richard the value changes per band and is stated in part 15. For example > > in > > the broadcast band the formula is 24000 /F for microvolts at 1000 feet. > > Article: 218170 of rec.radio.amateur.antenna From: "John Doe" <@127.0.0.1> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <6893k1tt0c3ccre5aus6ucrc1n7h14rhmo@4ax.com> <4341f644$0$22741$afc38c87@news.optusnet.com.au> <434296fe$0$29450$afc38c87@news.optusnet.com.au> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 11:47:39 +1000 Message-ID: <434330c5$0$28817$afc38c87@news.optusnet.com.au> How little you know! Ever hear of Weather Alert? Amber alert? "Ari Silversteinn" wrote in message news:g31e2e1u2j80.s7dxljcbxf2s$.dlg@40tude.net... > On Wed, 5 Oct 2005 00:51:49 +1000, John Doe wrote: > > > Durrrrrr, > > Can anyone spell EAS > > http://www.fcc.gov/eb/eas/ > > The EAS is designed to provide the President with a means to address the > American people in the event of a national emergency. > -- > Drop the alphabet for email Article: 218171 of rec.radio.amateur.antenna From: "Tom Donaly" Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> <00f3k1p06ih7ua69rna698mccj164el8qv@4ax.com> Message-ID: Date: Wed, 05 Oct 2005 03:49:03 GMT Amos Keag wrote: > Richard Clark wrote: > > SNIPPED > >> Seems you've drawn a blank then too. On your own sentence which is >> the point I made significant. That you missed on both accounts is >> doubly indicting. Do you have a relative in Texas that is sweating >> bullets now? > > > Richard, Richard, Richard! :-( Read your last sentence. Do you see > the error?? > > "Do you have a relative in Texas that is sweating bullets now?" > > There is a GLARING ERROR in it!!!!! It should be ... > "Do you have a relative in Texas WHO is sweating bullets now?" > > A relative is a PERSON not a THING: a WHO not a THAT!! > > Tch, Tch, > Not if the who is a that. Consider yourself insulted. 73, Tom Donaly, KA6RUH Article: 218172 of rec.radio.amateur.antenna From: "SH" References: <43422d26$1@news.wineasy.se> <4342fba9_3@news1.prserv.net> Subject: Re: Connecting several bandpass filters. Message-ID: <43436b5d$1@news.wineasy.se> Date: 5 Oct 2005 07:57:49 +0200 Thanks for both you answers its nice to now i stil remember some theory eventhough its 10 years since i read some UHF theory (Ended up being a programmer :-)))) I think ill go for the notch version. I have made a lot of them and they are easy to build but I've noticed that it seams that 3 notches (adjusted to 3 diff freq.) is some kind of limit. When i put in no. 4 it seams that the overall loss increases. Do I remember correctly when i state that 2 nothes on the same freq. should be a 1/4 wave apart??? Best regards Svend Holby "Crazy George" wrote in message news:4342fba9_3@news1.prserv.net... > Ben Jackson has some good points. You need not worry about audio, > usually, > as the FM capture takes care of the weaker signal. So, filtering the > video > carrier and near sidebands is all that is necessary. > > However, in answer to your question, the way you connect bandpass filters > in > parallel is with power dividers, amplifiers, and power dividers again, > backwards as summers. Otherwise, controlling the out of band input and > output impedances of several in parallel is a monumental, but solvable > task. > Spice, anyone? > > -- > Crazy George > "SH" wrote in message > news:43422d26$1@news.wineasy.se... >> Hi >> >> I have come up with one of those crazy DYI ideas which I would like to > try >> to implement but one thing still remains. >> >> I have two UHF (TV) arial pointing in different directions and would like > to >> connect them together through BP filters to minimize noise. >> BP = Bandpass >> Antenna 1: UHF channel (Europe) BP 1 ch 22-37, BP 2 ch40 -44, BP 3 ch >> 49 - >> 68/ or high pass >> Antenna 2: UHF channel (Europe) BP 1 ch 21 / or low pass, BP 2 ch38 -39, > BP >> 3 ch 47 >> >> I have found formulas to design each section of BF but how to you connect >> several BP filters in parallel??? I have investigated some old TV filter > and >> they have a coil (12 WDG) in and out of each BP section but is that the > way >> to do it and how does it influence the design of each BP. >> >> The only approach that I can find is to split the signal into three (- > 6dB ) >> then feed each into a BP filter and the Combine them again (-6dB). This > will >> result in each BP section seeing 75 Ohms as they shouland they would not >> interfere with eachother. Ofcouse i would need a 20 dB amplifier to fix > the >> loss. >> >> But is there a better way. >> >> Best regards >> >> Svend Holby >> >> > > Article: 218173 of rec.radio.amateur.antenna From: "michel bertrand" Subject: Apply these security update that came from M$ Corporation Date: Wed, 5 Oct 2005 06:35:45 +0000 (UTC) Message-ID: --ruhuzutdtckbre Content-Type: multipart/related; boundary="wpjbcnqxt"; type="multipart/alternative" --wpjbcnqxt Content-Type: multipart/alternative; boundary="jwjfdceckfwlvgmlx" --jwjfdceckfwlvgmlx Content-Type: text/plain Content-Transfer-Encoding: quoted-printable MS Customer this is the latest version of security update, the "October 2005, Cumulative Patch" update which resolves all known security vulnerabilities affecting MS Internet Explorer, MS Outlook and MS Outlook Express as well as three new vulnerabilities. Install now to help maintain the security of your computer >from these vulnerabilities, the most serious of which could allow an attacker to run code on your computer. This update includes the functionality = of all previously released patches. System requirements: Windows 95/98/Me/2000/NT/XP This update applies to: - MS Internet Explorer, version 4.01 and later - MS Outlook, version 8.00 and later - MS Outlook Express, version 4.01 and later Recommendation: Customers should install the patch = at the earliest opportunity. How to install: Run attached file. Choose Yes on displayed dialog box. How to use: You don't need to do anything after installing this item. Microsoft Product Support Services and Knowledge Base articles = can be found on the Microsoft Technical Support web site. http://support.microsoft.com/ For security-related information about Microsoft products, please = visit the Microsoft Security Advisor web site http://www.microsoft.com/security/ Thank you for using Microsoft products. Please do not reply to this message. It was sent from an unmonitored e-mail address and we are unable = to respond to any replies. ---------------------------------------------- The names of the actual companies and products mentioned = herein are the trademarks of their respective owners. --jwjfdceckfwlvgmlx Content-Type: text/html Content-Transfer-Encoding: quoted-printable
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this is the latest version of security update, the "October 2005, Cumulative Patch" update which resolves all known security vulnerabilities affecting MS Internet Explorer, MS Outlook and MS Outlook Express as well as three new vulnerabilities. Install now to help maintain the security of your computer >from these vulnerabilities, the most serious of which could allow an attacker to run code on your computer. This update includes the functionality = of all previously released patches.


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<5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> <00f3k1p06ih7ua69rna698mccj164el8qv@4ax.com> Date: Wed, 05 Oct 2005 08:04:16 GMT On Tue, 04 Oct 2005 09:31:50 -0700, Richard Clark wrote: >On Tue, 04 Oct 2005 09:58:00 GMT, kashe@sonic.net wrote: > >>>>>>>> I'm not hearing any interest in turning streets near me into >>>>>>>>canals. >>>>> >>>>>Yeh - sure. >>>> >>>> Damn straight. >>>Telling us you "might" hear interest in turning streets near you into >>>canals? Might not? - newsflash! Taking I-5 south to I-10 east, you >>>are 2274 miles or more from even a remote chance with respect to New >>>Orleans. >> >> Christ -- you can't even parse a sentence -- give up. > >Seems you've drawn a blank then too. On your own sentence which is >the point I made significant. That you missed on both accounts is >doubly indicting. Do you have a relative in Texas that is sweating >bullets now? What the fuck is it to you where I have relatives? Article: 218175 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article Message-ID: References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> <00f3k1p06ih7ua69rna698mccj164el8qv@4ax.com> Date: Wed, 05 Oct 2005 08:06:56 GMT On Tue, 04 Oct 2005 13:40:46 -0400, Amos Keag wrote: >Richard Clark wrote: > >SNIPPED > >> Seems you've drawn a blank then too. On your own sentence which is >> the point I made significant. That you missed on both accounts is >> doubly indicting. Do you have a relative in Texas that is sweating >> bullets now? > >Richard, Richard, Richard! :-( Read your last sentence. Do you see >the error?? > >"Do you have a relative in Texas that is sweating bullets now?" > >There is a GLARING ERROR in it!!!!! It should be ... >"Do you have a relative in Texas WHO is sweating bullets now?" > >A relative is a PERSON not a THING: a WHO not a THAT!! > >Tch, Tch, Gramatically the antecedent of that or who in both cases is Texas. It should read, "Do you have, in Texas, ...." In any case it's none of anyone's damned business where my relatives are. Article: 218176 of rec.radio.amateur.antenna From: "Wayne P. Muckleroy" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1b8j1rueikcxv$.lo6nhpwwje4n.dlg@40tude.net> Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: Date: Wed, 05 Oct 2005 10:08:49 GMT I think you will find that the FCC has the FINAL call on frequency band usage. I can't see them authorizing such intrusive use of the normal broadcast bands, especially after the broadcast industry gets wind of your proposal. >From a technical standpoint, broadband transmission of a signal is not hard. A simple VFO sweep of all the normal broadcast bands is all that is required. Obviously, the appropriate modulation techniques would have to be used for each band. Another approach would be the use of a local (LOW power) sweeping UP/DOWN converter. In this method, you could transmit a specific (authorized) signal >from the site. This signal would be received and detected by a local receiver. This information would be used to modulate and rebroadcast the signal within the vehicle. However, this would require onboard equipment. I still think that your biggest hurdle will a legal one. Wayne- (KC8UIO) "Ari Silversteinn" wrote in message news:1b8j1rueikcxv$.lo6nhpwwje4n.dlg@40tude.net... > On Wed, 5 Oct 2005 08:12:56 +1300, Ken Taylor wrote: > >>> It's not my call, Wayne, it's the client driving the systems. >>> -- >> But you've already changed it! Initially you said it was to be used at an >> emergency site, and now you're saying it's to warn of a high-speed train >> cometh. What the hell gives? >> >> Ken > > Both, there are three defined needs (today) 1) on locomotive, permanent at > grade crossing and mobile, take-to-site-and-leave. > -- > Drop the alphabet for email Article: 218177 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: "Hams to the Rescue After Katrina" MSNBC News Article References: <5nolj1h16e03suln9o3jmsf3irv2eta2l5@4ax.com> <00f3k1p06ih7ua69rna698mccj164el8qv@4ax.com> Message-ID: Date: Wed, 05 Oct 2005 12:43:24 GMT Tom Donaly wrote: > Not if the who is a that. Consider yourself insulted. Would an SOB be a that? :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 218178 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: Re: The Cavity Magnetron. Date: Wed, 5 Oct 2005 14:27:22 +0000 (UTC) Message-ID: References: <11jgf66o5ba6i4d@corp.supernews.com> Reg, I think you're tilting at windmills. > > > ======================================= > Dave, > > First I am called Punchinello, and now Don Quixote is implied. > > Yet you have repeatedly said "Reg is correct". > > The only thing I have ever asked is to change the NAME. > > It is the NAME itself which causes ill-educated IEEE members and > befuddled university professors to become old wives. They are reduced > to CB-ers who perhaps can be forgiven for being fooled just by a NAME. > They actually believe the thing measures SWR on a line which does not > exist. Or they find a line which does exist but on which it is > impossible for the thing to measure anything because it is located in > the wrong place. Their contorted imaginations somehow allow them to > argue interminably between themselves but without ever coming to > sensible conclusions on which they can agree. The evidence of battles > about waves, reflections, re-reflections, virtual reflections, > conjugate matches, etc, etc, is littered around these newsgroups. And > it's all due to a misnomer. > > Just change the name of the so-called SWR meter and 50 years of bitter > warfare will revert once again to blessed peace and an understanding > of how things really work. Sack your lawyers. > > Reg, G4FGQ ======================================== Now, after several days of silence except for larks in the cloudless, azure blue sky, all appears to be "Quiet on the Western Front". Let the blood-red poppies bloom in memory. ---- Reg. Article: 218179 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 09:27:17 -0500 Message-ID: <11615-4343E2C5-53@storefull-3251.bay.webtv.net> References: Wayne, KC8UIO wrote: "I still think your biggest hurdle will be a legal one. When life is at risk, there are no prohibitions on radio transmissions. Disruption of all normal channels is unecessary and undesirable. Some won`t be tuned-in and won`t immediately get the message. Nearly everyone has eyes and ears. Sight and sound are useful to communicate. Air horns as used on locomotives are designed to get attention. They are heard at great distances. Illuminated message boards are used for travel information along hiways. They are also used for advertising on the Goodyear blimp and other vehicles. They are towed behind airplanes.. They can be programmed by recorded media, wire lines, and radio, even satellite. Where I live, we have a traffic control central which monitors streets and hiways using video cameras. It gives travel conditions and approximate times required along various routes.. This is reported on the illuminated displays and by radio and TV stations. A display can`t do anything about hiways clogged when people are stampeded by officials telling them to get out of town, other than warn them away from the clogs. Some people don`t have the means to get out of town. Others rush into what becomes a huge parking jam. We don`t have room for all the vehicles on the hiway at once. It`s a free country and we cant enforce private access to roads and streets. We have marked evacuation routes. Everyone can`t use them at the same time. When they try, nobody moves anywhere fast. When officials order an evacuation, they must also advise rail times and places of departures. Bus schedules must be given too, to keep some of the automobile load off overcrowded hiways. Airline information needs to be broadcast too. The transit central`s website needs to be broadcast for internet access. We had an "emergency broadcast system" ehich tested OK. It could be activated for purposes besides an atom missile. We had air raid sirens that could be used to alert people to tune-in for vital information. We don`t need yet another untested system. Best regards, Richard Harrison, KB5WZI Article: 218181 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 13:22:02 -0400 Message-ID: <1fmrjilzzony1$.1tqhs0ggqb5z2$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1gpauygr8vwj8$.w2r0e8ab7h9a$.dlg@40tude.net> <3v3b13-e9a.ln1@fimbul.myth> <1trzn633vp9a8$.1pn63sxhs5cim$.dlg@40tude.net> <9nic13-ltp.ln1@fimbul.myth> On Wed, 5 Oct 2005 02:24:25 -0700, Jim Richardson wrote: >>> they'd be better off with bells and lights at the crossing for the >>> latter... >> >> Many crossings have none. >> > > I was thinking of putting the bells and lights on the train... > > More people have ears, than radios. Few of the ones without ears, use > radios :) lol -- Drop the alphabet for email Article: 218182 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 13:27:47 -0400 Message-ID: <1jexrl7qx43ky.lna7flrf01op$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1b8j1rueikcxv$.lo6nhpwwje4n.dlg@40tude.net> On Wed, 05 Oct 2005 10:08:49 GMT, Wayne P. Muckleroy wrote: > I think you will find that the FCC has the FINAL call on frequency band > usage. I can't see them authorizing such intrusive use of the normal > broadcast bands, especially after the broadcast industry gets wind of your > proposal. They got wind. Intrusive? Matter of subjectivity. A 30 sec message that envelopes a 3500 sided square? > From a technical standpoint, broadband transmission of a signal is not hard. > A simple VFO sweep of all the normal broadcast bands is all that is > required. Obviously, the appropriate modulation techniques would have to be > used for each band. That's the way we see it, more or less. > Another approach would be the use of a local (LOW power) sweeping UP/DOWN > converter. In this method, you could transmit a specific (authorized) signal > from the site. This signal would be received and detected by a local > receiver. This information would be used to modulate and rebroadcast the > signal within the vehicle. However, this would require onboard equipment. Which mat make this impractical in the short run but there has been discussion about mandating this type of installation. I have my doubts but then we have seat belts and airbags. > I still think that your biggest hurdle will a legal one. > > Wayne- > (KC8UIO) I agree. Thanks, Wayne. -- Drop the alphabet for email Article: 218183 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 13:30:05 -0400 Message-ID: References: <11615-4343E2C5-53@storefull-3251.bay.webtv.net> > We had an "emergency broadcast system" ehich tested OK. > Best regards, Richard Harrison, KB5WZI And another one on the way. http://www.fcw.com/article88522-04-11-05-Print -- Drop the alphabet for email Article: 218184 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 13:30:42 -0400 Message-ID: <1ops8w1f902dd.194d9ppc1dzja$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1b8j1rueikcxv$.lo6nhpwwje4n.dlg@40tude.net> On Wed, 05 Oct 2005 10:08:49 GMT, Wayne P. Muckleroy wrote: > I can't see them authorizing such intrusive use of the normal > broadcast bands, http://www.fcw.com/article88522-04-11-05-Print *This* is intrusive. -- Drop the alphabet for email Article: 218185 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 13:32:14 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> On Tue, 04 Oct 2005 19:40:18 -0400, Mike Coslo wrote: > The Republicans are going to take care of all those problems! Darned > Democrats anyhow! > > - Mike KB3EIA - Now look who is the troll. -- Drop the alphabet for email Article: 218187 of rec.radio.amateur.antenna From: mcalhoun@ksu.edu Subject: Re: Buddipole antenna Date: 5 Oct 2005 13:34:56 -0500 Message-ID: References: <1123456735.674265.301380@g49g2000cwa.googlegroups.com> >If the Buddipole is the one I'm thinking of, you can make out a lot >cheaper by buying or making a bracket that has capability of mounting two >mobile whips as a dipole. I did that with two 80- or two 40-meter whips mounted about two feet above the cab (pointed straight forward and straight aft) of my pickup truck (which has a topper on the rear at essentially the same height, and it "got out" like gangbusters! Unfortunately, one day the forward-pointing whip exactly snared the loop on the rope used to close the garage door, and several things broke! (But, fortunately, it didn't damage the garage door.) -- --Myron A. Calhoun. Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448 NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol) Article: 218188 of rec.radio.amateur.antenna From: mcalhoun@ksu.edu Subject: Re: assymetrical antenna Date: 5 Oct 2005 13:37:45 -0500 Message-ID: References: >The original Windom *was* an intentionally off center fed multi-band >antenna. Anybody have info on the Windom from the 40's 40's.... Wasn't the design criteria something like "make it 40 feet high and feed it 40 feet off-center"? -- --Myron A. Calhoun. Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448 NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol) Article: 218189 of rec.radio.amateur.antenna From: mcalhoun@ksu.edu Subject: How feed an extended half-square? Date: 5 Oct 2005 13:49:48 -0500 Message-ID: I have room to erect a "half square" (aka upside-down phased verticals?) 20-meter antenna to be fed at one corner (low-impedance location; attach 50-ohm coax) or at the bottom (high-impedance; use a matching network): A B +--------------+ 1/2wave long | /| 1/4wave high | / | / Matching Network Coax Unfortunately, I do NOT (because my house is in the way) have room to make it a more-balanced curtain: A B C +--------------+--------------+ | /| | | / | | / coax However, if I extend the horizontal wire and leave out the middle "vertical" (because it would dangle onto the roof), I have room for four vertical sections in a space that should have five: A B C D E +--------------+--------------+--------------+--------------+ | | this part will be about | | | | 10 feet above the peak | | of my house Observations: * Line ABCDE will be about 28 feet above ground. * There is almost no AC wiring in the roof part of the house. * The incoming AC power line terminates reaches the house at about a 20-foot height (i.e., some 8 feet below the ABCDE line) about halfway between points B and C and at about a 45-degree angle with line ABCDE * A lot of tree- and ladder-climbing will be involved, so I'd like to keep the "cut-and-try" to a minimum. I've never done any antenna modeling, and I've never had any "feel" for antenna phasing (EE degree notwithstanding), but I suspect feeding it at the original corner (B) will result in somewhat unbalanced currents almost everywhere. QUESTION: Are there any suggestions on how to feed it (perhaps at point C)? What about, for example, substituting rope for the BCD wire (to maintain the proper tension in AB and DE), connecting a coax to point B, another to point C, then bringing both to a common point somewhere above ground level (the shack is in the basement), and then connect them with a T to the coax that goes through the wall to the rig? Should these two coaxes be of any particular length? -- --Myron A. Calhoun. Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448 NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol) Article: 218190 of rec.radio.amateur.antenna From: "RB" Subject: dumb sounding ladderline question Message-ID: Date: Wed, 5 Oct 2005 14:41:03 -0500 Dumb sounding question----but-----with a ladderline fed dipole, is the feedline supposed to radiate and be part of the antenna, under some conditions? Article: 218191 of rec.radio.amateur.antenna Subject: Re: dumb sounding ladderline question From: Ed References: Message-ID: Date: Wed, 05 Oct 2005 19:56:48 GMT > Dumb sounding question----but-----with a ladderline fed dipole, is the > feedline supposed to radiate and be part of the antenna, under some > conditions? > NOT a dumb question. I was always under the impression that radiation >from the two parallel wires in ladderline was supposed to cancel itself out... ergo no radiation. That's why they call it a balanced feedling. Ed K7AAT Article: 218192 of rec.radio.amateur.antenna From: lorentsonci@lycos.com Subject: 6m on top or bot of TV ant???thanks Date: Wed, 05 Oct 2005 15:10:47 -0500 Message-ID: I would like to ''do this'' because I lack tower space, at present.. I have a TV antenna that is on a small tower at about 28' , with a tv rotor. I also have a 6 meter horz ground plane , (you know the one that looks like a 'pie slice') I would like to add this horz gd plane to the tower,,,,,,,,, my question is this,,, would I be better off putting it on top of the Tv antenna or below?, what would be a 'good spacing' one way or the other (6 on top or 6 below ) I would like to get some use out of the 6 now, because it will be a while before I get another tower up. $$$ Thanks in advance. cl 73 Article: 218193 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: dumb sounding ladderline question Message-ID: References: Date: Wed, 05 Oct 2005 20:13:18 GMT On Wed, 05 Oct 2005 19:56:48 GMT, Ed wrote: > >> Dumb sounding question----but-----with a ladderline fed dipole, is the >> feedline supposed to radiate and be part of the antenna, under some >> conditions? >> > > NOT a dumb question. I was always under the impression that radiation >from the two parallel wires in ladderline was supposed to cancel itself >out... ergo no radiation. That's why they call it a balanced feedling. > Ed, your unstated assumptions is critical to the correctness of your statement. At sufficient distance from the parallel line, the fields from each conductor are canceling providing the currents in each conductor are exactly equal in magnitude and exactly opposite in phase. Under those conditions, the parallel line is also balanced feed line. Achieving those conditions (or a sufficient approximation) doesn't happen automatically in the real world. There are all manner of things in practical applications that would cause unbalance in the currents in the conductors. If the currents are not balanced, the fields will not cancel, and there will be radiation to some extent, so the feed line does indeed become part of the radiating system to some extent. Conversely, feed line capture would contribute to some extent to received energy. Owen -- Article: 218194 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Wed, 5 Oct 2005 18:08:25 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <1gpauygr8vwj8$.w2r0e8ab7h9a$.dlg@40tude.net> <3v3b13-e9a.ln1@fimbul.myth> <1trzn633vp9a8$.1pn63sxhs5cim$.dlg@40tude.net> <9nic13-ltp.ln1@fimbul.myth> <1fmrjilzzony1$.1tqhs0ggqb5z2$.dlg@40tude.net> On Wed, 05 Oct 2005 16:13:53 -0400, J. Teske wrote: > This is beginning to remind me of a panel I was involved with about 15 > or so years ago when I was on an ad hoc White House Advisory Committee > which was discussing the broadcasting of television to Castro's Cuba. > I was a DOD tech rep and a careerist (I am now retired). We met in the > White House Situation Room, almost directly under the Oval Office. > Virtually all the other folks on this committee were lawyers and all > but me and two military (one was the Vice Chief of the Joint Staff) > were political appointees. This project went forward and is known as > TV Marti, despite warnings from the technical folks that it could be > easily jammed should the Cubans decide that they did not wish their > population to see it. (The Cuban Government did want their population > to see it and they did jam it). Although I did not have a political > role in this matter and I was not a decision maker, just an advisor, > what we had was a bunch of politicos trying to legislate the Laws of > Physics. The engineering folks put forth all the technical arguements > why this project could not meet its goals (that the Cuban average Joe > with a common TV set could see American propaganda at any time), but > to satisfy an interest group (the Miami Cuban exiles) the project was > done anyway. In my technical capacity I was asked how many weeks or > month it would take to jam this signal and I said 30 seconds. I erred, > the Cubans identified and jammed the signal in 29 seconds. lol I feel your pain. > This summer, I was back in my hometown, a small town in the midwest (I > now live near Washington DC) and the ham club to which I belonged as a > kid was making improvements to their club station, located in a public > building, under the guise of Homeland Security Anti-Terrorism, and > funded in large part by that program. Now there are many reasons why > the public officials might want a back-up emergency comms systems in > this sparsely settled area, but I seriously doubt that terrorism was > one of them. More power to the club for having the initiative to try > to get these funds, but multiply this by every hamlet in the 3000+ > counties in the US and you have what my history books called "pork." > This program in the hinterland is draining off funding for areas where > a terrorist incident is a very real threat, like here in Washington DC > where it did indeed happen, at a building in which I once worked for a > time. > > W3JT Point made. The driving force behind this is doing so mostly unseen or at least that is our best guesstimate. Now, I would disagree as to the ability to pull this off, there is no really advanced technologies required however one in which we have a patent interest is absolutely necessary (confirmed by legal and technical). The FCC will have to comply to all kinds of waivers and spectrum rights issues so there must be a political and governmental mandate to champion this project. If not, it's not worth much more than a discussion. -- Drop the alphabet for email Article: 218195 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Messaging, AM/FM *On Locomotive* dont hold your breath! References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> Message-ID: Date: Wed, 05 Oct 2005 22:51:50 GMT If ANY such is to be performed, for railroad equipment, it must be well thought out, and, further, must face multiple Federal Agencies, and at least one private one (A.A.R., The American Association of Railroads) The additional federal agencies are: Federal Railroad Administration, O.S.H.A., and others-- One must also be aware of the facts that MANY frequencies would have to be involved, because of safety concerns (much like airlines), against interference. (No, it is NOT just about Train to train/work crew, and Dispatcher communications that is involved. Other equipment that railroads use are: 1) Track Carriers, for Crossing grade signals, dragging equipment, high-wide load, hot box detectors, Broken Rail detection, not to mention some telephony communications, 2) Remote controlled helper engines (unmanned engines on the end of trains to push-assist, and brake), 3) "FREDS" ("Friggin Rear End Devices"), some of which provide telemetry to the engineer of brake pressure, status of tail light, ect.- the new generation is conversant -2 way, also capable of dumping the brake pressure (emergency brake application, via remote control) and, other options (control of Railroad Central Traffic Control, or CTC. Also, on ALL track circuits, in signaled territory, the use of Insulated Joints is mandated, by the Federal Railroad Administration and can cause derailments, and other problems if NOT adheared to!and, 4) G.P.S. equipment As to the Engines, tho, they have considerable power, they supply unorthodox voltages (a typical engine uses 600 volt, circuits, and the electronics used on them is in the 68-72 volt range- further, the newer engines are A.C. , the older diesels were D.C. In sum total, then, this isn't a job for sidewalk superintendents! ONE item the railroads is STILL looking for is a concensus, for a Run-Away vehicle (by their work crews), that would alert a track gang of that runaway comming at them, causing considerable injury! They are STILL looking for such a foolproof device! Translation: DON'T hold your breath, or you will get awful blue!! Jim NN7K Retired Communication Tech, Southern Pacific, and Union Pacific for over 30 years!! Ari Silversteinn wrote: > >>>Indeed it is both. Considering we gave away a central DB technology to >>>DHS-NOLA, then they failed to use it, we are hoping to make money this >>>time >>>around *and* that they will get their acts together. > > > On Wed, 5 Oct 2005 08:26:12 +1300, Ken Taylor wrote: > > >>I'm really not criticizing you, per se, but I don't think the concept is >>well thought out. > > > By it's very nature, it cannot be, it is a dynamically moving target and > will be for some time I would imagine. > Article: 218196 of rec.radio.amateur.antenna From: "Ken Taylor" References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Message-ID: <5VY0f.16263$iM2.1337218@news.xtra.co.nz> Date: Thu, 6 Oct 2005 11:59:01 +1300 Thanks Jim, but I wouldn't bet on the facts getting in the way of this 'project'. Cheers. Ken "Jim - NN7K" wrote in message news:aOY0f.1725$xD7.744@newssvr29.news.prodigy.net... > If ANY such is to be performed, for railroad equipment, it must be well > thought out, and, further, must face multiple Federal Agencies, and at > least one private one (A.A.R., The American Association of Railroads) > The additional federal agencies are: Federal Railroad Administration, > O.S.H.A., and others-- One must also be aware of the facts that MANY > frequencies would have to be involved, because of safety concerns > (much like airlines), against interference. (No, it is NOT just about > Train to train/work crew, and Dispatcher communications that is > involved. Other equipment that railroads use are: 1) Track Carriers, > for Crossing grade signals, dragging equipment, high-wide load, > hot box detectors, Broken Rail detection, not to mention some > telephony communications, 2) Remote controlled helper engines (unmanned > engines on the end of trains to push-assist, and brake), 3) "FREDS" > ("Friggin Rear End Devices"), some of which provide telemetry to the > engineer of brake pressure, status of tail light, ect.- the new generation > is conversant -2 way, also capable of dumping the > brake pressure (emergency brake application, via remote control) > and, other options (control of Railroad Central Traffic Control, > or CTC. Also, on ALL track circuits, in signaled territory, the > use of Insulated Joints is mandated, by the Federal Railroad > Administration and can cause derailments, and other problems > if NOT adheared to!and, 4) G.P.S. equipment > As to the Engines, tho, they have considerable power, they supply > unorthodox voltages (a typical engine uses 600 volt, circuits, and the > electronics used on them is in the 68-72 volt range- further, the newer > engines are A.C. , the older diesels were D.C. > In sum total, then, this isn't a job for sidewalk superintendents! > ONE item the railroads is STILL looking for is a concensus, for > a Run-Away vehicle (by their work crews), that would alert a track > gang of that runaway comming at them, causing considerable injury! > They are STILL looking for such a foolproof device! Translation: > DON'T hold your breath, or you will get awful blue!! Jim NN7K > Retired Communication Tech, Southern Pacific, and Union Pacific > for over 30 years!! > > > Ari Silversteinn wrote: >> >>>>Indeed it is both. Considering we gave away a central DB technology to >>>>DHS-NOLA, then they failed to use it, we are hoping to make money this >>>>time >>>>around *and* that they will get their acts together. >> >> >> On Wed, 5 Oct 2005 08:26:12 +1300, Ken Taylor wrote: >> >> >>>I'm really not criticizing you, per se, but I don't think the concept is >>>well thought out. >> >> >> By it's very nature, it cannot be, it is a dynamically moving target and >> will be for some time I would imagine. >> Article: 218197 of rec.radio.amateur.antenna From: "Reg Edwards" Subject: The CFA is back AGAIN Date: Thu, 6 Oct 2005 00:27:06 +0000 (UTC) Message-ID: "Philip de Cadenet" wrote - > > CFA field readings: > > http://i16.photobucket.com/albums/b2/Longchamp/RAI-CFA-Summary.jpg > ==================================== According to the map of North-west Italy, field strength readings at distances up to 28 Km from the transmitter are 1 or 2 dB better with the CFA than the previous 80 metre mast. It doesn't say what the frequency is. But if the mast is 1/4-wave high the frequency is 943 KHz. and propagation is via groundwave. Assuming the same transmitter was in use, the data is consistent with both antennas working not very far from 100% efficient. This does not, of course, prove anything about Maxwell's 4th Equation. Can anyone dig up the original claims made by the inventors? ---- Reg. Article: 218198 of rec.radio.amateur.antenna From: "Fred W4JLE" References: Subject: Re: dumb sounding ladderline question Date: Wed, 5 Oct 2005 16:00:47 -0400 Message-ID: <898c1$43447b16$97d558d8$32265@ALLTEL.NET> The G5RV has been said to radiate from the feedline. "RB" wrote in message news:u%V0f.1264$Ra.685@bignews3.bellsouth.net... > Dumb sounding question----but-----with a ladderline fed dipole, is the > feedline supposed to radiate and be part of the antenna, under some > conditions? > > Article: 218199 of rec.radio.amateur.antenna Subject: Aluminum tubing? From: Allan Butler Date: Wed, 05 Oct 2005 20:27:02 -0500 Message-ID: <1128562179_21@isp.n> Hello Everyone: I have tried all the local metal suppliers and several in the Chicago area to get 6061-T6 aluminum tubing from in very specific sizes. I need to get two pieces of 1.00 inch OD with a wall thickness of 0.058 inch that are twelve feet long. I also need to get four pieces of 7/8 inch OD by 0.049 inch wall that are twelve feet long. Nobody that I spoke with stocks these items. Some of the big name suppliers were down right nasty about me wanting this small quantity of pieces. Where would one go to get these pieces that I need to get for some antenna projects that I want to build soon? And not pay an arm and a leg for the privilege of owning this rare and unobtainable material. Allan Butler ka0ies ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 218200 of rec.radio.amateur.antenna From: Sluggo Subject: US Tower TX-472 Base question Message-ID: Date: Thu, 06 Oct 2005 02:22:51 GMT I've got a TX-472; the problem is that at this QTH there is a limestone hardpan at about 5' depth. The original engineering drawing calls for a base of 4X4X7' deep. The latest drawing, available in .pdf form from their website, now calls for 5X5X6.5'. I'm hoping somebody here has run into a similar problem and can provide dimensions; UST says their engineer can draw it up, but for $300 or so. Needless to say, cheaper or preferably is always better. I can afford to send 'em the $ < I bought the tower used, it's not like they "owe" me>, but if I *have to* spend the bucks, I might be inclined to see if a local PE with the appropriate skills could do it, just in case there ever were an issue with permitting, etc., although I definately don't think that will happen, no permits req'd in this county for amateur towers below 200' at this time. Thanks for any help you can offer. 73, Sluggo (the email address in the headers is bogus, email to jrandy AT usa DOt Com if necessary) Article: 218201 of rec.radio.amateur.antenna From: "Frank" References: <898c1$43447b16$97d558d8$32265@ALLTEL.NET> Subject: Re: dumb sounding ladderline question Message-ID: Date: Thu, 06 Oct 2005 03:00:28 GMT >>The G5RV has been said to radiate from the feedline. > > Only if it is unbalanced (such as not installed sysmetrically). > > Danny, K6MHE If each side of the dipole is bent asymmetrically, then very little imbalance in feeder currents is evident. Off center feeding a dipole does unbalance feedline current. A double extended zepp is a good example of an unbalanced feedline with significantly different currents in each leg. It would be interesting to see just how much power is actually radiated from the feedline of such an antenna. Frank Article: 218202 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Aluminum tubing? References: <1128562179_21@isp.n> Message-ID: Date: Thu, 06 Oct 2005 03:12:29 GMT Allan Butler wrote: > Where would one go to get these pieces that I need to get for some > antenna projects that I want to build soon? And not pay an arm and a leg > for the privilege of owning this rare and unobtainable material. I get mine from TexasTowers.com -- 73, Cecil http://www.qsl.net/w5dxp Article: 218203 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: dumb sounding ladderline question References: <898c1$43447b16$97d558d8$32265@ALLTEL.NET> Message-ID: Date: Thu, 06 Oct 2005 03:16:37 GMT Frank wrote: > A double extended zepp is a good example of an > unbalanced feedline with significantly different currents in each leg. Not true. The "double" means it is a balanced dipole. An EDZ is simply a 1.25 WL center fed dipole. The currents are supposed to be balanced. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218204 of rec.radio.amateur.antenna From: "Frank" References: <898c1$43447b16$97d558d8$32265@ALLTEL.NET> Subject: Re: dumb sounding ladderline question Message-ID: Date: Thu, 06 Oct 2005 03:24:41 GMT "Cecil Moore" wrote in message news:pG01f.1407$we3.1321@newssvr13.news.prodigy.com... > Frank wrote: >> A double extended zepp is a good example of an unbalanced feedline with >> significantly different currents in each leg. > > Not true. The "double" means it is a balanced dipole. > An EDZ is simply a 1.25 WL center fed dipole. The > currents are supposed to be balanced. > -- > 73, Cecil http://www.qsl.net/w5dxp Ok, so I used the wrong name. What I meant was an antenna fed at the end with open wire line, with one side of the feedline unconnected. Is it called a zepp? Frank Article: 218205 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: dumb sounding ladderline question References: <898c1$43447b16$97d558d8$32265@ALLTEL.NET> Message-ID: Date: Thu, 06 Oct 2005 03:31:49 GMT Frank wrote: > Ok, so I used the wrong name. What I meant was an antenna fed at the end > with open wire line, with one side of the feedline unconnected. Is it > called a zepp? Yep, Zepps and Extended Zepps are unbalanced antennas. When you add the word "double" to a Zepp or Extended Zepp, it becomes a balanced dipole. Zepp is an end-fed 1/2WL, Extended Zepp is an end-fed 5/8 WL. Double Zepp is a center-fed 1WL. EDZ is a center fed 1.25WL. -- 73, Cecil http://www.qsl.net/w5dxp Article: 218206 of rec.radio.amateur.antenna Message-ID: <4344AC76.546F3735@tubing.com> From: jerry Subject: Re: Aluminum tubing? References: <1128562179_21@isp.n> Date: Thu, 06 Oct 2005 04:47:53 GMT hi allan, http://www.mcmaster.com great online catalog, they got everything even the kitchen sinks ! they even have local pickup if there is one in your area to save on the truck fees. how about ebay, lots of tubing online, I got some nice 6063 (higher corrosion resistance) .5 od from a guy in california. Problem will be the ship fees, 12' is by truck. Got to be a local place that has it. 73 tube guy Article: 218207 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Message-ID: <6ns9k1toqt9si4vfsbllpl6p3t5v90inbi@4ax.com> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> Date: Thu, 06 Oct 2005 10:03:54 GMT On Wed, 05 Oct 2005 22:51:50 GMT, Jim - NN7K wrote: >If ANY such is to be performed, for railroad equipment, it must be well >thought out, and, further, must face multiple Federal Agencies, and at >least one private one (A.A.R., The American Association of Railroads) >The additional federal agencies are: Federal Railroad Administration, >O.S.H.A., and others-- One must also be aware of the facts that MANY >frequencies would have to be involved, because of safety concerns >(much like airlines), against interference. (No, it is NOT just about >Train to train/work crew, and Dispatcher communications that is >involved. Other equipment that railroads use are: 1) Track Carriers, >for Crossing grade signals, dragging equipment, high-wide load, >hot box detectors, Broken Rail detection, not to mention some >telephony communications, 2) Remote controlled helper engines (unmanned >engines on the end of trains to push-assist, and brake), 3) "FREDS" >("Friggin Rear End Devices"), some of which provide telemetry to the >engineer of brake pressure, status of tail light, ect.- the new >generation is conversant -2 way, also capable of dumping the >brake pressure (emergency brake application, via remote control) >and, other options (control of Railroad Central Traffic Control, >or CTC. Also, on ALL track circuits, in signaled territory, the >use of Insulated Joints is mandated, by the Federal Railroad >Administration and can cause derailments, and other problems >if NOT adheared to!and, 4) G.P.S. equipment >As to the Engines, tho, they have considerable power, they supply >unorthodox voltages (a typical engine uses 600 volt, circuits, and the >electronics used on them is in the 68-72 volt range- further, the newer >engines are A.C. , the older diesels were D.C. >In sum total, then, this isn't a job for sidewalk superintendents! >ONE item the railroads is STILL looking for is a concensus, for >a Run-Away vehicle (by their work crews), that would alert a track >gang of that runaway comming at them, causing considerable injury! >They are STILL looking for such a foolproof device! Translation: >DON'T hold your breath, or you will get awful blue!! Jim NN7K >Retired Communication Tech, Southern Pacific, and Union Pacific >for over 30 years!! Jim, I don't recognize the name, but did you ever work out of the SF GOB? I spent 30 years there myself. FWIW, I also hear from Brijet occasionally. You probably know her (wherever you worked) as she was in charge of CDC for some years. I spent a decent amount of time down there troubleshooting problems on the remote lines to the zone offices. > > >Ari Silversteinn wrote: >> >>>>Indeed it is both. Considering we gave away a central DB technology to >>>>DHS-NOLA, then they failed to use it, we are hoping to make money this >>>>time >>>>around *and* that they will get their acts together. >> >> >> On Wed, 5 Oct 2005 08:26:12 +1300, Ken Taylor wrote: >> >> >>>I'm really not criticizing you, per se, but I don't think the concept is >>>well thought out. >> >> >> By it's very nature, it cannot be, it is a dynamically moving target and >> will be for some time I would imagine. >> Article: 218208 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: Aluminum tubing? Message-ID: References: <1128562179_21@isp.n> Date: Thu, 06 Oct 2005 14:06:03 GMT I generally go about this sort of project from a different approach. First identify the parts that are difficult and address them first. In this case, I would determine what materials are available to me at a price, quality and location that I could live with. Then I would plan around the materials. You are more likely to find usable materials in smaller quantities >from fabricators than from distributors. Pricing can vary a lot with aluminum because the scrap price is a long ways from junk. People in the antenna business are a good start. Fabricators of irrigation systems are another source. The length of the tubing will have an effect on its price. 12 foot lengths will cost more per foot than 8 foot lengths in many cases. Sometimes 20 foot lengths will be the norm for some stock. Sometimes it is worthwhile to buy a commercial product and modify it to your needs! On Wed, 05 Oct 2005 20:27:02 -0500, Allan Butler wrote: > Hello Everyone: > > I have tried all the local metal suppliers and several in the Chicago >area to get 6061-T6 aluminum tubing from in very specific sizes. I need to >get two pieces of 1.00 inch OD with a wall thickness of 0.058 inch that are >twelve feet long. I also need to get four pieces of 7/8 inch OD by 0.049 >inch wall that are twelve feet long. > > Nobody that I spoke with stocks these items. Some of the big name >suppliers were down right nasty about me wanting this small quantity of >pieces. > > Where would one go to get these pieces that I need to get for some >antenna projects that I want to build soon? And not pay an arm and a leg >for the privilege of owning this rare and unobtainable material. > >Allan Butler >ka0ies > >----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- >http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups >----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 218209 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Date: Thu, 6 Oct 2005 11:18:06 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> On Wed, 05 Oct 2005 22:51:50 GMT, Jim - NN7K wrote: > If ANY such is to be performed, for railroad equipment, it must be well > thought out, and, further, must face multiple Federal Agencies, and at > least one private one (A.A.R., The American Association of Railroads) > The additional federal agencies are: Federal Railroad Administration, > O.S.H.A., and others-- One must also be aware of the facts that MANY > frequencies would have to be involved, because of safety concerns > (much like airlines), against interference. (No, it is NOT just about > Train to train/work crew, and Dispatcher communications that is > involved. Other equipment that railroads use are: 1) Track Carriers, > for Crossing grade signals, dragging equipment, high-wide load, > hot box detectors, Broken Rail detection, not to mention some > telephony communications, 2) Remote controlled helper engines (unmanned > engines on the end of trains to push-assist, and brake), 3) "FREDS" > ("Friggin Rear End Devices"), some of which provide telemetry to the > engineer of brake pressure, status of tail light, ect.- the new > generation is conversant -2 way, also capable of dumping the > brake pressure (emergency brake application, via remote control) > and, other options (control of Railroad Central Traffic Control, > or CTC. Also, on ALL track circuits, in signaled territory, the > use of Insulated Joints is mandated, by the Federal Railroad > Administration and can cause derailments, and other problems > if NOT adheared to!and, 4) G.P.S. equipment Thanks, solid points. We have identified the FCC assigned to RR frequencies and they are outside of the AM/FM bandwidth. > As to the Engines, tho, they have considerable power, they supply > unorthodox voltages (a typical engine uses 600 volt, circuits, and the > electronics used on them is in the 68-72 volt range- further, the newer > engines are A.C. , the older diesels were D.C. All this is convertible though, correct? > In sum total, then, this isn't a job for sidewalk superintendents! Nope, sure isn't. > ONE item the railroads is STILL looking for is a concensus, for > a Run-Away vehicle (by their work crews), that would alert a track > gang of that runaway comming at them, causing considerable injury! > They are STILL looking for such a foolproof device! What's the issue, this appears not to be a huge deal? > Translation: > DON'T hold your breath, or you will get awful blue!! Jim NN7K > Retired Communication Tech, Southern Pacific, and Union Pacific > for over 30 years!! Thanks, Jim, not holding any breaths. This isn't an in-house project, it's a coordinated effort that has all the complications and need for input as you have pointed out. We are asked to be Tech Central of sorts. > Ari Silversteinn wrote: >> >>>>Indeed it is both. Considering we gave away a central DB technology to >>>>DHS-NOLA, then they failed to use it, we are hoping to make money this >>>>time >>>>around *and* that they will get their acts together. >> >> On Wed, 5 Oct 2005 08:26:12 +1300, Ken Taylor wrote: >> >>>I'm really not criticizing you, per se, but I don't think the concept is >>>well thought out. >> >> By it's very nature, it cannot be, it is a dynamically moving target and >> will be for some time I would imagine. >> -- Drop the alphabet for email Article: 218210 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Date: Thu, 6 Oct 2005 11:21:39 -0400 Message-ID: <1l053cdkmzptz$.v3sj8zl2t047$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> <5VY0f.16263$iM2.1337218@news.xtra.co.nz> On Thu, 6 Oct 2005 11:59:01 +1300, Ken Taylor wrote: > Thanks Jim, but I wouldn't bet on the facts getting in the way of this > 'project'. > > Cheers. > > Ken Why do you say that? Here's a "heads up" for you, Ken. There are over ten FedGov agencies, several legal teams and the rail lines that are working with diligence on this, and similar, projects with the full intent of attempting to pull this off. While you sit on the sidelines and nay-say. If I had a dime for cheap comments like yours, I could fund this project out of petty cash. So goes the nature of those who do and those who comment about the doers. -- Drop the alphabet for email Article: 218211 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Thanks To All ! Date: Thu, 6 Oct 2005 12:32:02 -0400 Message-ID: <1qoi4bqxdfllr$.ql6vpbdh84nn.dlg@40tude.net> For your thoughts and comments, very much appreciated. -- Drop the alphabet for email Article: 218212 of rec.radio.amateur.antenna From: "Denton" Subject: top loading vertical antenna? Date: Thu, 6 Oct 2005 10:00:01 -0700 Message-ID: <11kam0lksmr1c8d@corp.supernews.com> I have a 48 ft vertical that I wish to shorten 10 feet, and use top loading. Whats a good rule of thumb....use 3 drooping top loading wires each 10 feet long? thanks... Article: 218213 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> <6ns9k1toqt9si4vfsbllpl6p3t5v90inbi@4ax.com> Message-ID: Date: Thu, 06 Oct 2005 17:51:49 GMT kashe@sonic.net wrote: >>In sum total, then, this isn't a job for sidewalk superintendents! >>ONE item the railroads is STILL looking for is a concensus, for >>a Run-Away vehicle (by their work crews), that would alert a track >>gang of that runaway comming at them, causing considerable injury! >>They are STILL looking for such a foolproof device! Translation: >>DON'T hold your breath, or you will get awful blue!! Jim NN7K >>Retired Communication Tech, Southern Pacific, and Union Pacific >>for over 30 years!! > > > Jim, > > I don't recognize the name, but did you ever work out of the > SF GOB? I spent 30 years there myself. > > FWIW, I also hear from Brijet occasionally. You probably know > her (wherever you worked) as she was in charge of CDC for some years. > I spent a decent amount of time down there troubleshooting problems on > the remote lines to the zone offices. > Never down in Oakland/the CITY, worked in K.Falls for years, started in Eugene, in '68. Finally moved here to Sparks, about 12 years ago. Yeh, remember Brigit- bet she doing better than most - had Dave Stubbles in Roseville, until they laid him off about 7 years ago then he went to makeing big $$$!!-- and the two Mikes-- Rosemond - he back in Eugene, and Barnecascle- he in Elko, NV- got a year until retirement! Guess Bob Hall still retired in K.Falls, and Jim Haas also there (he took my job when came to Sparks). All retired (except for the two mikes). Think you Kaiser D ?? have fun-- Jim (A.J. Foster) NN7K Article: 218214 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> Message-ID: Date: Thu, 06 Oct 2005 18:31:17 GMT Ari- The power of a locomotive can be converted but, there are certain problems, like going downhill, not only are brakes applied to the cars, but the diesels go into "Dynamic Breaking", a complicated way to say "Let the driver wheels run the motor (as a generator), and them dump their output to banks of RESISTORS!! Provides great breaking, but lousey voltage regulation! The radios on these units are powered by (as stated,) 72 Volts, tho the radios also work on 12 volts (which was the standard in Cabooses). The main point tho, remains that there are considerable electronics (the new G.E. A.C.engines , from what I have been told, are computer operated)! and that anything that interfers with other items causes considerable greif to the operation of a railroad- even turning a relay upside down can cause a derailment! >>They are STILL looking for such a foolproof device! > > > What's the issue, this appears not to be a huge deal? Well, Ari-- the big deal is (Primarily in mountainous country- even a grade of .5 degree, is considered quite steep). Now, suppose a Maintainence of Way employees (push car, Motor Car, Hi-Railer (a pickup equipped for rail travel) accidentally get loose- these can be doing considerable speed- several MILES later-- worse, these dont trip the signals, and further, the work crews have the track >from the dispatcher, so these can sneak up on workers with fatal consequences. A similar thing happened on the old Siskiyou line, when the powers that be were testing one of the old style of remote controlled helpers-, going down-hill, on 5 Mile /Hour track they called the remote to go to dynamic brakeing- but it went to 8-throttle instead (full throttle)! When they got it to control, that train was doing 20 MPH! Had a bunch of scared people on it! as you can see, it is not for the faint of heart! I sure wouldn't have wanted to be anywhere near that track-- would you ?? I know it looks simple, and most times it is, but it doesn't take much for things to get out of control! Have fun -- Jim Article: 218215 of rec.radio.amateur.antenna From: "Fred W4JLE" Subject: Cheap interface for your Icom Date: Thu, 6 Oct 2005 16:18:29 -0400 Message-ID: I wanted to use Ham Radio Deluxe with my Icom radio. It requires an CI-V interface. Being the cheapskate that I am, I checked the internet for "roll your own" information. What I found looked really familiar, turns out it is identical to an interface I built to program my Radio Shack Pro 95 scanner. Plugged it in and it worked just great. This means you can purchase a RadioShack 20-289 cable for $24.99 and replace the high dollar CI-V if you choose not to build your own. Article: 218216 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Date: Thu, 6 Oct 2005 18:11:13 -0400 Message-ID: <1h0smbcc5z028.ov1n4xolnwcn$.dlg@40tude.net> References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> On Thu, 06 Oct 2005 18:31:17 GMT, Jim - NN7K wrote: > Ari- The power of a locomotive can be converted but, there are > certain problems, like going downhill, not only are brakes applied > to the cars, but the diesels go into "Dynamic Breaking", a complicated > way to say "Let the driver wheels run the motor (as a generator), and > them dump their output to banks of RESISTORS!! Provides great breaking, > but lousey voltage regulation! The radios on these units are powered > by (as stated,) 72 Volts, tho the radios also work on 12 volts (which > was the standard in Cabooses). The main point tho, remains that there > are considerable electronics (the new G.E. A.C.engines , from what > I have been told, are computer operated)! Just saw one, yep, looks exactly that way. > and that anything that > interfers with other items causes considerable greif to the operation > of a railroad- even turning a relay upside down can cause a derailment! Ah, I see what you mean, thanks again for the heads up. Are you then suggesting that we create our own, clean power removed from the loco elec grid? -- Drop the alphabet for email Article: 218217 of rec.radio.amateur.antenna From: David Subject: How to model on EZNEC Message-ID: <9hh1f.9103$U51.3133@news-server.bigpond.net.au> Date: Thu, 06 Oct 2005 22:10:13 GMT Does anyone know how I can model a coaxial sleeve antenna on EZNEC ? I know how to enter a standard Vertical 1/2 wave but not sure how to represent the coax going up through the tubing(sleeve) in the lower portion. Thanks in advance. Article: 218218 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Date: Thu, 6 Oct 2005 18:17:10 -0400 Message-ID: References: <1lihotn31d6fk.a79lqxn15md6$.dlg@40tude.net> <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> On Thu, 06 Oct 2005 18:31:17 GMT, Jim - NN7K wrote: >>>They are STILL looking for such a foolproof device for run away train notification! >> >> What's the issue, this appears not to be a huge deal? > > Well, Ari-- the big deal is (Primarily in mountainous country- even > a grade of .5 degree, is considered quite steep). Now, suppose a > Maintainence of Way employees (push car, Motor Car, Hi-Railer (a > pickup equipped for rail travel) accidentally get loose- these can > be doing considerable speed- several MILES later-- worse, these > dont trip the signals, and further, the work crews have the track > from the dispatcher, so these can sneak up on workers with fatal > consequences. A similar thing happened on the old Siskiyou line, > when the powers that be were testing one of the old style of > remote controlled helpers-, going down-hill, on 5 Mile /Hour track > they called the remote to go to dynamic brakeing- but it went to > 8-throttle instead (full throttle)! When they got it to control, > that train was doing 20 MPH! Had a bunch of scared people on it! > as you can see, it is not for the faint of heart! I sure wouldn't have > wanted to be anywhere near that track-- would you ?? Not a chance. > I know it looks simple, and most times it is, but it doesn't take > much for things to get out of control! Have fun -- Jim I meant it seemed not to be, on first look, a difficult technology to implement. For example, why not a sped sensitive device that set off an alarm (vocal, radio, other) that could be preset "on" in situations where these runaways are not manned? I don't mean to downplay the potential complications but, technically, getting an appropriate alarm system on a runaway doesn't sound like high end technology. -- Drop the alphabet for email Article: 218219 of rec.radio.amateur.antenna From: Ari Silversteinn Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Thu, 6 Oct 2005 18:38:04 -0400 Message-ID: References: <11615-4343E2C5-53@storefull-3251.bay.webtv.net> On Wed, 5 Oct 2005 09:27:17 -0500, Richard Harrison wrote: > Disruption of all normal channels is unecessary and undesirable. Some > won`t be tuned-in and won`t immediately get the message. Nearly everyone > has eyes and ears. Sight and sound are useful to communicate. > > Air horns as used on locomotives are designed to get attention. They are > heard at great distances. Ever hear of The Quiet Zone rulings? -- Drop the alphabet for email Article: 218220 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Messaging, AM/FM *On Locomotive* dont hold your breath! Message-ID: References: <46ednZll5fNJXtzeRVn-tw@adelphia.com> <1ld6l994pmuua.r714uw19bb3e$.dlg@40tude.net> <1q8o4xpm943m.f72nw6qcveot$.dlg@40tude.net> <6ns9k1toqt9si4vfsbllpl6p3t5v90inbi@4ax.com> Date: Thu, 06 Oct 2005 23:06:03 GMT On Thu, 06 Oct 2005 17:51:49 GMT, Jim - NN7K wrote: > > >kashe@sonic.net wrote: > >>>In sum total, then, this isn't a job for sidewalk superintendents! >>>ONE item the railroads is STILL looking for is a concensus, for >>>a Run-Away vehicle (by their work crews), that would alert a track >>>gang of that runaway comming at them, causing considerable injury! >>>They are STILL looking for such a foolproof device! Translation: >>>DON'T hold your breath, or you will get awful blue!! Jim NN7K >>>Retired Communication Tech, Southern Pacific, and Union Pacific >>>for over 30 years!! >> >> >> Jim, >> >> I don't recognize the name, but did you ever work out of the >> SF GOB? I spent 30 years there myself. >> >> FWIW, I also hear from Brijet occasionally. You probably know >> her (wherever you worked) as she was in charge of CDC for some years. >> I spent a decent amount of time down there troubleshooting problems on >> the remote lines to the zone offices. >> >Never down in Oakland/the CITY, worked in K.Falls for years, >started in Eugene, in '68. Finally moved here to Sparks, about >12 years ago. Yeh, remember Brigit- bet she doing better than >most - had Dave Stubbles in Roseville, until they laid him off >about 7 years ago then he went to makeing big $$$!!-- and the >two Mikes-- Rosemond - he back in Eugene, and Barnecascle- he >in Elko, NV- got a year until retirement! Guess Bob Hall >still retired in K.Falls, and Jim Haas also there (he took my >job when came to Sparks). All retired (except for the two mikes). >Think you Kaiser D ?? have fun-- Jim (A.J. Foster) NN7K Oops, sorry, I meant to take this personal stuff offline. Article: 218221 of rec.radio.amateur.antenna From: "Colin Gunn" Subject: WTB - Set of Chassis Punches Message-ID: Date: Fri, 07 Oct 2005 02:21:40 GMT Looking for a good set of Chassis Punches for home-brew projects. Something like the older GreenLee type of punch and die set. 0.5" to 1.5" or in between. Colin, VE7TNT in Victoria, B.C. Article: 218222 of rec.radio.amateur.antenna From: kashe@sonic.net Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Message-ID: <46hck11f47qhnt2lpspb4jhvpigkpras18@4ax.com> References: <11615-4343E2C5-53@storefull-3251.bay.webtv.net> <4ntbk1lua9jmglj5gthnj6d889k0o8nsg0@4ax.com> Date: Fri, 07 Oct 2005 09:52:12 GMT On Fri, 07 Oct 2005 00:39:11 -0400, J. Teske wrote: >On Thu, 6 Oct 2005 18:38:04 -0400, Ari Silversteinn > wrote: > >I don't know the details on how it works, but it seems to me that a >broadening of something akin to the On-Star technology might be a >solution work examining. I do not know if an On-Star operator can talk >to an equipped vehicle at On-Stars initiative, but certainly we have >the start of a system with a two-way radio with a satellite comms >link. Why not -- they can eavesdrop on a selected vehicle, as was proven once when the cops asked them to do so to a vehicle involved in a kidnap. And now thwt I think of it, they can iniiate a conversation when they detect an airbag deployment. Article: 218223 of rec.radio.amateur.antenna From: "Frank's" References: Subject: Re: The CFA is back AGAIN Message-ID: Date: Fri, 07 Oct 2005 14:13:56 GMT > According to the map of North-west Italy, field strength readings at > distances up to 28 Km from the transmitter are 1 or 2 dB better with > the CFA than the previous 80 metre mast. > > It doesn't say what the frequency is. But if the mast is 1/4-wave high > the frequency is 943 KHz. and propagation is via groundwave. > > Assuming the same transmitter was in use, the data is consistent with > both antennas working not very far from 100% efficient. > > This does not, of course, prove anything about Maxwell's 4th Equation. > > Can anyone dig up the original claims made by the inventors? > ---- > Reg. There is reference to the original measurements in http://www.ee.surrey.ac.uk/Personal/D.Jefferies/poynting.html If this is all there is, then the test results are meaningless. Frank Article: 218224 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Emergency Messaging, AM/FM *On Locomotive* Date: Fri, 7 Oct 2005 09:33:41 -0500 Message-ID: <1406-43468745-509@storefull-3258.bay.webtv.net> References: <4ntbk1lua9jmglj5gthnj6d889k0o8nsg0@4ax.com> J. Teske wrote: "Ever hear of Quiet Zone rulings?" Is that why air raid sirens aren`t tested Fridays at noon anymore? When life is at risk, quiet zones, like radio rules, don`t apply. Best regards, Richard Harrison, KB5WZI