Article: 224734 of rec.radio.amateur.antenna From: Bruce in Alaska Subject: Re: sgc dipole? References: <1148390757.341256.120320@i40g2000cwc.googlegroups.com> <1276n13d85ld919@corp.supernews.com> Message-ID: Date: Thu, 25 May 2006 18:42:15 GMT In article <1276n13d85ld919@corp.supernews.com>, dplatt@radagast.org (Dave Platt) wrote: snipped > As I understand it (and this is all second- and third-hand knowledge): > the SGC tuners (like the SEA tuners from which they're said to have > been copied and like a lot of similar tuners from Motorola and others) > were designed primarily to match short verticals (whips and wires) > working against a much larger ground system. They're designed for > unbalanced applicatios. Their original application was marine and > vehicle use, with the tuner very robustly "bonded" to the metal > chassis of the vehicle. The manuals still make it clear that a large, > well-bonded ground/counterpoise system connected directly to the tuner > chassis is what these tuners really "want to see". The acceptable-SWR > range for a dipole to be matched is rather limited... IIRC the SGC-230 > manual says that it's limited to 5:1 or so. > a note here, the SGC, SEA, and Motorola tuners were all deisgned to feed unbalanced antennas. There were a few hardy souls who took two SEA 1612B's and made one slave to the CPU of the other, so as to make a balanced type tuner, with a bit of success, but the firmware was never designed to do this and it was a hack to be sure. > When used to center-feed a dipole, making the ground-side leg longer > than the hot-side leg increases the capacitance to ground on that side > and may tend to mimic the environment for which the tuners were really > designed. I have a few 1612B's that drive dipole antennas with vairous feed systems scattered around Alaska, and they seem to funcntion at least as good as an unbalanced Marconi type antenna in the same fixed location. The whole point of trying this was to be able to ignore the RF Ground at these fixed sites, which mostly were on Glacal Till, which is just about the same as a sheet of Glass, as far as RF is concerened. When I was first entertaining this idea, I spent a lot of time with Bill Forgey and Mark Johnson @ SEA talking about the possibilites, and we came to the conclusion that I would work, if one took the 50Ohm Feedline, DC Power Lines, and Tuned Anunciator Lines and wound the Trifiler on a big Torriod to isolate the tuner from the the radio. There are a few that tried to use a 1:1 Balun across the output of the tuner to ground, and then feeding a balanced feedline/antenna system, with some sucess, but some of the better MF/HF Antenna Designers that I consulted, were dubious if that approch was a real valid system. > > As to _why_ they want to see it - my guess is that it has to do with > the details of the tuner's internal circuitry (it's an L or PI tuner), > the tuning-setting search algorithm in the microprocessor, and perhaps > the electrical details of the SWR-and-impedance measuring/bridge > circuit. > > The manual comments that if the counterpoise system isn't > significantly bigger than the radiator, the tuner's microcontroller > may "become confused" and try to feed power to the ground system > rather than to the radiator. Yes, I know, this doesn't really makes > sense electrically... I suspect that it really means that the > matching-component search algorithm starts making decisions which > actually drive the system further away from a good match rather than > towards it. It's also possible that such installations are more prone > to high levels of RF current flow on the feedline from the > transmitter, and also to high common-mode RF flow on the power and > control lines, and that this RF might tend to confuse the tuner's > SWR-and-impedance sensors and thus disrupt the match-search process. > > My own experiences with an SGC tuner seem to confirm the limitations > and warnings that SGC publishes about the hookup required to establish > a match. A couple of years ago I picked up a first-generation SGC 230 > (apparently never used, as it was still in the original shipping box > and bag) at a hamfest for all of $30. I've tried it, and I _can_ get > it to work, but in my installation it's finicky in the extreme about > its ability to match a wire. > All of the autotuners of this type have serious limitations, especially as they approch the 1/2Wave point of the physical antenna, where impedances ramp up to infinite. All of them use the Phase, Frequency, and Forward/Reverse Power, type sensers to let the cpu know what is going on as it ripples thru the Fixed L and C in Binary Increments. Some of the firmware actually has some smarts built in, but most use the same basic algorythem the Sillbe wrote for the original Motorola Micom Tuners. Bruce in alaska who was around the BIZ, when all this was going on.... -- add a <2> before @ Article: 224735 of rec.radio.amateur.antenna From: You Subject: Re: Grounding a metal roof References: <1148272981_5573@sp6iad.superfeed.net> Message-ID: Date: Thu, 25 May 2006 18:46:37 GMT In article , "Sal M. Onella" wrote: > One guy in radio transmits a carrier, > while listening on a nearby freq. If he hears anything, he grabs his > handheld and barks, "What was that you just tapped on?" Real Radiomen would use a Spectrum Analyser to look for this type of stuff........Ears are so linear...... Article: 224736 of rec.radio.amateur.antenna From: Me Subject: Re: Yacht Rf ground and radials References: <447311d0_1@news.iprimus.com.au> Message-ID: Date: Thu, 25 May 2006 18:59:04 GMT In article , "Eric Fairbank" wrote: > Icom needs to modernize their thinking and get rid of their "old school" > installation guides. Wire radials are the way to go on your sailboat. Not > copper foil or wide copper strips, just plain old 14 gauge wire radials. I > suggest you read some of the threads about this on the Maritime Mobile Ham > Forum from people with real world experience with marine HF installations. > You'll find the answers to your questions there: > > http://cruisenews.net/cgi-bin/mmham/webbbs_config.pl > > Eric > Radials are the WORST type of RF Ground for ANY MF/HF Marine Antenna System. Anyone who has any sense at all can understand this, just thinbk about it. First, they have to be very long when dealing with frequencies below 4 Mhz, and unless you have a BIG vessel, you don't have room for 1/4 wave radials. Second, Radials need to be resonant to do any good, and that limits them to one or two frequencies, where Marine Radios need to have antennas that can operate on many Bands, which is why non-resonate, low impedance, RF Grounds, are used by most all Commercial Marine Antenna Systems. I suggest that you go out and get 30 Years of Commercial Marine Radio Installation and Operation Experience, and then come back and explain it all to us, again.......in detail.....if you live that long.... Me been there, done that...... Article: 224737 of rec.radio.amateur.antenna From: "Cecil Moore" Subject: Brainteaser Message-ID: Date: Thu, 25 May 2006 20:18:01 GMT Last week I posted a brainteaser over on qrz.com. Nobody figured it out. I wonder how many on r.r.a.a can figure it out. Given: A one second long lossless transmission line with a steady-state forward power of 200 watts and a reflected power of 100 watts. How many joules are contained in that feedline? -- 73, Cecil, W5DXP Article: 224738 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Brainteaser Date: Thu, 25 May 2006 16:35:00 -0500 Message-ID: <20319-44762304-243@storefull-3258.bay.webtv.net> References: Cecil, W5DXP wrote: "How many joules are contained in that feedline?" I`ll speculate that after one second, 200 joules are contained in the forward wave on that line. Then, after two seconds, another 100 joules has been reflected back toward the line feedpoint where it opposes growth of power input to the line. Total joules on the line is 300. Forward power minus the reflected power equals 100 watts being supplied by the generator to the load with 200 watts forward power and 100 watts reflrcted power in the line. Best regards, Richard Harrison, KB5WZI Article: 224739 of rec.radio.amateur.antenna From: richardharrison@webtv.net (Richard Harrison) Subject: Re: Yacht Rf ground and radials Date: Thu, 25 May 2006 16:52:25 -0500 Message-ID: <20319-44762719-246@storefull-3258.bay.webtv.net> References: <447311d0_1@news.iprimus.com.au> Will wrote: "How can this work when the Dynaplate is below seawater?" In the old days, an Apelco radio, a Webster antenna, and a Dynaplate ground put you in the marine radio business just fine. Best regards, Richard Harrison, KB5WZI Article: 224740 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> Message-ID: Date: Thu, 25 May 2006 22:04:12 GMT Richard Harrison wrote: > Cecil, W5DXP wrote: > "How many joules are contained in that feedline?" > > Total joules on the line is 300. That can be shown to be true by noting that during the transient buildup to steady-state, 300 joules sourced by the generator have not yet reached the load. That remains true until the generator is powered down, i.e. all during steady-state. > Forward power minus the reflected power equals 100 watts being supplied > by the generator to the load with 200 watts forward power and 100 watts > reflrcted power in the line. But what about the people who say there's no energy in the reflected wave? Reckon how they sweep all those joules, whose energy must be conserved, under the rug? :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 224741 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: G..g..g..en....genetic??? References: <1148595210.353997.301530@i40g2000cwc.googlegroups.com> Message-ID: Date: Thu, 25 May 2006 22:16:39 GMT n3ox.dan@gmail.com wrote: > It's a thought. I'd be interested in what other people think... the > word "genetic" could even be dropped if it is a sticking point since I > don't really care what particular approach is taken to push the design > toward some goal. The genetic algorithms are recursive. Maybe "recursive" would be a better term for something that is not alive. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224742 of rec.radio.amateur.antenna From: dplatt@radagast.org (Dave Platt) Subject: Re: G..g..g..en....genetic??? Date: Thu, 25 May 2006 22:37:46 -0000 Message-ID: <127ccdq44m0pic7@corp.supernews.com> References: <1148595210.353997.301530@i40g2000cwc.googlegroups.com> In article <1148595210.353997.301530@i40g2000cwc.googlegroups.com>, n3ox.dan@gmail.com wrote: >I'm interested in the possibility of using this kind of search of the >space of possible antennas in those situations that we all end up in, >you've put the antenna too close to the tower, you're shoehorning it >into the attic, or you really really need to mount it on the bumper and >not on the roof. > >Has anyone written any software that could do this? I guess what I'm >imagining is that you input the location and extent of fixed >conductors, the tower, the car (yes i know it's hard), the wiring in >the walls, whatever, and then you let the computer chew on what >particular weird zig-zag of metal will give you the pattern you *want* >rather than living with the pattern of an antenna designed without the >additional conductors in place. There are already some general-purpose genetic-optimization packages freely available in languages such as Perl. It ought to be possible to write a set of wrappers which uses such a package to manage the "genome" of an antenna-design space being searched, convert each individual genome to a NEC configuration, run NEC2 or a similar package, and extract the results. >For attic antennas, you could have a figure of merit based on some >combination of minimizing loss and minimizing the currents induced in >the fixed conductors. Keep that RF off the house wiring, and the noise >off the antenna, while still radiating most of your power? I'm by no means an expert in this field, but based on some reading I did a month or so ago I have a feeling that a single figure-of-merit is not necessarily the right way to go. The search process can end up being extremely (and perhaps excessively) sensitive to small changes in the weighting factors. Rather, most people these days seem to approach such problems from the point of view of Pareto optimality. That is, there are a number of figures of merit, which evaluate or rate different (and usually independent) objectives. A possible solution is Pareto-optimal if any change you make in it results in at least one figure of merit getting worse. Optimization system based on Pareto optimality maintain a population of solutions (many or most of which are Pareto-optimal) and then generate new solutions from that set (possibly by "genetic" means). You end up with a bunch of workable Pareto-optimal solutions, and then pick from among them at the end of the process - possibly by applying a final formula to merge the various figures-of-merit for each solution into a final "how good is it?" figure. Deferring this final merging until the end of the process seems to help keep the search system from prematurely glomming onto what turns out to be a local maximum in the goodness function. It'd also be a good idea to have some way of evaluating how "brittle" a possible solution is. If even a slight change in one of the parameters causes a previously-optimal solution to become very non-optimal, then it's probably not a good choice for use in an amateur installation. You might want to look for clusters of Pareto-optimal solutions, and then pick one from near the center of the cluster as being both "representative", and also "robust"... small changes in the parameters wouldn't take you outside of the general area of the cluster. >I guess there was some prior discussion of use of genetic optimization >processes to design amateur antennas being of dubious legality because >of patents... if this is the case, forget I even posted it. That's certainly an issue. Someone wanting to pursue this might be well advised to do some research into older texts, find out what the state-of-the-art was a couple of decades ago, and base any implementation solely on techniques which were in the public domain back then or which were covered by patents which have since lapsed. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! Article: 224743 of rec.radio.amateur.antenna From: Jim Kelley Subject: Re: Brainteaser Date: Thu, 25 May 2006 16:07:58 -0700 Message-ID: References: <20319-44762304-243@storefull-3258.bay.webtv.net> One should also carefully consider the more interesting variation of the problem: an open transmission line. In the steady state we have 100 watts forward, 100 watts reflected, 200 Joules in the line, and 0 watts being sourced by the generator. :-) ac6xg Cecil Moore wrote: > Richard Harrison wrote: > >> Cecil, W5DXP wrote: >> "How many joules are contained in that feedline?" >> >> Total joules on the line is 300. > > > That can be shown to be true by noting that during the > transient buildup to steady-state, 300 joules sourced > by the generator have not yet reached the load. That > remains true until the generator is powered down, i.e. > all during steady-state. > >> Forward power minus the reflected power equals 100 watts being supplied >> by the generator to the load with 200 watts forward power and 100 watts >> reflrcted power in the line. > > > But what about the people who say there's no energy in the > reflected wave? Reckon how they sweep all those joules, > whose energy must be conserved, under the rug? :-) Article: 224744 of rec.radio.amateur.antenna Date: Thu, 25 May 2006 18:51:34 -0500 From: Tom Ring Subject: Re: What happens if you pipe the output of one radio in to 2 amps? References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> Message-ID: <44764307$0$1016$39cecf19@news.twtelecom.net> Yuri Blanarovich wrote: > "Tom Ring" wrote in message > news:4475127b$0$1010$39cecf19@news.twtelecom.net... > >>Yuri Blanarovich wrote: >> >> >>>There is another potential problem if feeding two amps to two antennas >>>that are reasonably close: RF from one antenna is induced into the other >>>antenna, gets fed into the amp and causes some interference (mixing ?) >>>that shows up as a raspy signal. >>>Tried it, and heard it on another station attempting the same setup. >>>It seems that it would be easier to control the phasing at the input of >>>the PAs, but the above effect messes it up, unless antennas are widely >>>separated and they do not "feed" each other setup. >>>So, it appears that it is better to use one bigger amp and use proper >>>phasing to feed the two or more antennas. >>> >> >>Well, the expert, or should I say, the new GURU, has spoken. He seems to >>know all about this complex subject. >> > > > Aaaah, here chimes in another W8JI worshipper, who can not read posting, > understand it and reply intelligently, but resorting to snotty, personal, > pathetic remarks. You may have noticed that I do not take crap and respond > in kind. > > >>I know I will never try this again, as my previous efforts, which seemed >>to work, could not possibly have done so. Obviously Wilkenson hybrids are >>useless, likewise any ring hybrids, and all other methods of >>splitting/combining a transmitter feed. >> > > READ IT AGAIN carefully, I have not say that "Wilkenson" (learn spelling) > > Thank you for showing your feathers and displaying your depth! > Your picture would look pretier if you engaged in technical, civil > discussions, rather than that "W8JI thing". > > > >>tom >>K0TAR >> > > > Yuri Blanarovich, K3BU, VE3BMV etc. > > Yuru As far as replying in kind, I've been reading your posts for quite a while, and I haven't noticed that you withhold any criticisms. If the only errors you made were typos, this crowd wouldn't have a problem with you. And I know when I am out of my depth, and to keep my mouth firmly shut, as apparently you do not. tom K0TAR Article: 224745 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> Message-ID: Date: Fri, 26 May 2006 00:30:29 GMT Jim Kelley wrote: > One should also carefully consider the more interesting variation of the > problem: an open transmission line. In the steady state we have 100 > watts forward, 100 watts reflected, 200 Joules in the line, and 0 watts > being sourced by the generator. :-) Yes, but the 200 joules in the line was previously sourced by the generator during the transient state. It's hard to sweep 200 joules under the reflected power rug. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224746 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Explanation wanted Date: Thu, 25 May 2006 17:33:34 -0700 Message-ID: <127cj74i0av6482@corp.supernews.com> References: Dave wrote: > > ARRL can't just 'rush to get this book reprinted' because they are NOT > the author. The author has copyright [$$$] interests in publication. > > The author is: Kirk A. Kleinschmidt, NT0Z. Try contacting him. Although there can be and are exceptions, a publisher generally acquires the copyright from the author prior to publication, so it can reprint as it chooses. But it's also not unusual for the contract to stipulate that the copyright revert back to the author when the publisher is no longer interested (e.g., after the last printing they intend to do has sold out). Roy Lewallen, W7EL Article: 224747 of rec.radio.amateur.antenna From: gwatts Subject: Re: One of these days. Very Soon now. References: <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net> Message-ID: Date: Fri, 26 May 2006 00:38:34 GMT Radio Buff wrote: > You'll open your QST magazine to the Silent key section and Ham Radio will > be listed. > > sc (yawn) Article: 224748 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> Message-ID: Date: Fri, 26 May 2006 00:50:36 GMT Jim Kelley wrote: > One should also carefully consider the more interesting variation of the > problem: an open transmission line. In the steady state we have 100 > watts forward, 100 watts reflected, 200 Joules in the line, and 0 watts > being sourced by the generator. :-) Expanding on my earlier response - For the first two seconds, the source doesn't know it is looking into an open transmission line so a 100 watt source would faithfully output 200 joules into a one second long open circuit transmission line. That 200 joules cannot be destroyed. Is it mere coincidence that the forward and reflected waves are 100 joules/sec*(one second), exactly equal to the 200 joules supplied by the source? -- 73, Cecil http://www.qsl.net/w5dxp Article: 224749 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> Subject: Re: What happens if you pipe the output of one radio in to 2 amps? Message-ID: Date: Thu, 25 May 2006 21:52:50 -0400 "Tom Ring" wrote in message news:44764307$0$1016$39cecf19@news.twtelecom.net... > Yuri Blanarovich wrote: > >> "Tom Ring" wrote in message >> news:4475127b$0$1010$39cecf19@news.twtelecom.net... >> >>>Yuri Blanarovich wrote: >>> >>> >>>>There is another potential problem if feeding two amps to two antennas >>>>that are reasonably close: RF from one antenna is induced into the other >>>>antenna, gets fed into the amp and causes some interference (mixing ?) >>>>that shows up as a raspy signal. >>>>Tried it, and heard it on another station attempting the same setup. >>>>It seems that it would be easier to control the phasing at the input of >>>>the PAs, but the above effect messes it up, unless antennas are widely >>>>separated and they do not "feed" each other setup. >>>>So, it appears that it is better to use one bigger amp and use proper >>>>phasing to feed the two or more antennas. >>>> >>> >>>Well, the expert, or should I say, the new GURU, has spoken. He seems to >>>know all about this complex subject. >>> >> >> >> Aaaah, here chimes in another W8JI worshipper, who can not read posting, >> understand it and reply intelligently, but resorting to snotty, personal, >> pathetic remarks. You may have noticed that I do not take crap and >> respond in kind. >> >> >>>I know I will never try this again, as my previous efforts, which seemed >>>to work, could not possibly have done so. Obviously Wilkenson hybrids >>>are useless, likewise any ring hybrids, and all other methods of >>>splitting/combining a transmitter feed. >>> >> >> READ IT AGAIN carefully, I have not say that "Wilkenson" (learn spelling) > >> Thank you for showing your feathers and displaying your depth! >> Your picture would look pretier if you engaged in technical, civil >> discussions, rather than that "W8JI thing". >> >> >> >>>tom >>>K0TAR >>> >> >> >> Yuri Blanarovich, K3BU, VE3BMV etc. > > Yuru > > As far as replying in kind, I've been reading your posts for quite a > while, and I haven't noticed that you withhold any criticisms. > > If the only errors you made were typos, this crowd wouldn't have a problem > with you. > > And I know when I am out of my depth, and to keep my mouth firmly shut, as > apparently you do not. > > tom > K0TAR Typical response. Just read what happened in this thread. Look at what I wrote, look at what you responded. I am not criticizing, I respond to crap and personal attacks in kind, not very nice, but I do not need to put up with snotty remarks and personal BS. Looks like hurlers don't like when one responds in kind. If discussion is about technical matters, I provide help where I can or feel like. If jerk doesn't like it and comes riding high horse, then I get on my horse too, which happened with W8JI (we go way back) and now with you. I provided my opinion on 2 PAs to 2 ANTs, you twisted it and snapped GURU crap on it, Richard Clark was right behind you. I hate to see you when you are out of your depth. Now you come on with lecture about "crowd having problem with me"? You discuss technical matters in a civil way, I respond in kind, you pull out snotty crap, and I don't take it. Mark it down and next time if you want do the technical exchange I am open for dialog. What you want me to do to be "nice"? Accept the "truth" that current along the loading coil is ALWAYS the same, that shield IS the antenna, that electrostatic shield can't possibly work, that antenna is not an antenna? Where I come from, we fight for truth and if needed give life for it. If you want me to bow to false teachings, or to take crap, look somewhere else. So you want to try to be nice and discuss the problems with intermods between two PAs feeding two antennas or play W8JI? I can also engage on Wilkinson's hybrids, I use them. Let's stay with the subjects of this NG and keep the crap for the toilets. -- Yuri Blanarovich, K3BU, VE3BMV Article: 224750 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net> <12a6p.9m3.17.1@news.alt.net> Subject: Re: One of these days. Very Soon now. Message-ID: Date: Thu, 25 May 2006 21:59:19 -0400 "Roger" wrote in message news:12a6p.9m3.17.1@news.alt.net... > Yeah, but the senile old farts still believe they are not only > *first responders* but that they are on the cutting edge > of technology. Let them wallow in their delusions of how > important ham radio is. > > Our "radio" club is more of a social circle. Rarely is anything > technical dicussed, just gossip about other hams. We > meet at Golden Corral. When someone brings their kids along, > the senile old farts start yammering about future hams, and when > is he going to get his ham ticket? Meanwhile, the kids sit > there and eat with iPods stuck in their ears, cell phones in their > hands, and chattering about IM and MySpace.com All of > which may just as well be a foreign language to the delusional > old farts. LOL! Serves the OF right! They should not have invented and developed that stuff, shudda stayed with stone tablets. This year we celebrate Tesla's 150th birthday - da first hams and greatest engineering genius that gave us so much, yet those with iPods that can't read their diplomas have no clue. -- Yuri Blanarovich, K3BU, VE3BMV Article: 224751 of rec.radio.amateur.antenna Date: Thu, 25 May 2006 21:35:18 -0500 From: Tom Ring Subject: Re: Brainteaser References: <1148590736.680643.311690@i39g2000cwa.googlegroups.com> Message-ID: <44766966$0$1018$39cecf19@news.twtelecom.net> Dr. Honeydew wrote: > I had Beaker set up an experiment to test this, and after he put out > the fire he started in his hair when the first load he tried melted a > hole in the lab bench, he finally got it set up right. He determined > that the mass of the line increased by about 3.338 femtograms when > powered as compared with it unpowered. We're now looking into what to > do with the line, as it's cluttering up the lab, and we're open to > suggestions. > > Regards, > Bunsen > That is the best response we will get. Even if there are correct ones! tom K0TAR Article: 224752 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: Incoming signal elevation question Date: Thu, 25 May 2006 22:48:05 -0400 Message-ID: <127cr1qk2re2v0a@corp.supernews.com> References: An equation that I leave in my HP calculator interrelates the important parameters. T = take-of-angle (up from horizon) D = distance in Mm (40 Mm is all of the way around the earth) H = virtual height of ionosphere in km Calculator is using angles in degrees. Single hop Cos(T) / Cos(T + 4.5*D) = 1 + H/6366 F2 H for 40 degrees north is between about 250 and 370. 73 Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net "Ken Bessler" wrote in message news:VEmag.22577$4H.10017@dukeread03... > Lets assume a single hop 40m signal from 400 miles away. What > elevation angle does it arrive at? Both stations are using inverted V's > at nominal height. There are no large bodies of water in between. > > Daytime and/or nighttime. > > -- > 73's de Ken KG0WX - Article: 224753 of rec.radio.amateur.antenna From: Buck Subject: Re: Brainteaser Message-ID: References: <20319-44762304-243@storefull-3258.bay.webtv.net> Date: Thu, 25 May 2006 22:52:31 -0400 On Thu, 25 May 2006 22:04:12 GMT, Cecil Moore wrote: >But what about the people who say there's no energy in the >reflected wave? Reckon how they sweep all those joules, >whose energy must be conserved, under the rug? :-) with a jouler's brush? -- 73 for now Buck N4PGW Article: 224754 of rec.radio.amateur.antenna From: "U-Know-Who" References: <1148333653.989066.182600@38g2000cwa.googlegroups.com> <1148333799.022539.52100@j33g2000cwa.googlegroups.com> <1148410520.479296.296360@j73g2000cwa.googlegroups.com> <1148513694.742031.233820@38g2000cwa.googlegroups.com> <7m9dg.58262$Qq.45028@tornado.texas.rr.com> <1148531248.944859.28630@38g2000cwa.googlegroups.com> Subject: Re: What radio equipment do you own Markie? Message-ID: Date: Fri, 26 May 2006 03:12:21 GMT "an_old_friend" wrote in message news:1148531248.944859.28630@38g2000cwa.googlegroups.com... > > U-Know-Who wrote: >> "an_old_friend" wrote in message >> news:1148513694.742031.233820@38g2000cwa.googlegroups.com... >> > >> > Howard W3CQH wrote: >> >> Why don't you take this CRAP off line to your friends - it doesn't >> >> belong >> >> in >> >> any of the HAM RADIO newsgroups! >> >> >> > becuase he is too much of a cowardly child to do so >> > >> > I thank you sir for puting the blamewhere it belongs on the posters of >> > such crap >> > >> > for my part Id be glad not to discuss such a subject in any radio NG if >> > the rest of the NG would only do the same >> > >> >> Read the subject, put your money where your mouth is. > fine partail inventory > > 2 sattelite rig (ft 847w which has hf and 6m all mode) and( the Icom > 901h wiith 1.2 gig unit) satetlites are one my my favortie moide > altough > > several general dual (2m 440 Fm) icom and kewood the Kenwood jas been > fitted with thei VC -H1 SSTV unit > > a 6m fm aliinco Mfj 6 m USB > > hTs a CB ht (with sbb too boot and and adjusted to allow 10m op whch > should matter soon enough) the relitively new Yeaszu quad band FM, > alincio 222 FM, the small alinco monoband pagers (2m and 440 )FM I hgot > for my wife also a ham now a icom HT 2m sport is at the end of the > model name working RS HT for 2m and 440 the RS mini 440 fm they made > some years back. > > other gear rs 10 m moble (been using it to drive tranverts to vhf and > uhf bands > > tranververters for all mode acces to 222 band and 900mhz band > > I am amps for 6 m (all mode) 2 meter and 440 amp ( I have several in > aossrted sizes) > > Fast scan tranmiter units (full analog tv) tranmiters for 440 and 900 > mhz ham bands > > i have ana asortment of RC gear including a 6m Rc unit > > cb gear am unit instal in my bed room and my fathers and the ham shack > the shack and my pick have ssb cappple cb and daul band ham FM, my AATV > (ampihp ATV) has 2 m FM VHF marinem and cb am > > pair xceiver wfm (gunn diode type homobreww unit for 5 and 10 gig > I know I am over looking a few thing here and there > > the staion is capple of operting all mode on all ham from 160m to 1.2 > gig except the relitively new 60m alocation as well as cb am usb lsb > the log includes various mode inculding a HSCW MS and EME botht of the > latter using CW (computer generated and decoded since I can't do it > manually) some where I have the gear to put the APRS station back on > the air but a couple of peices have been hiding in the dreaded "safe > place" since our move > Wow, got me beat. All I have is an Icom 746 that has been opened up. Basically transmits from 1-170 Mhz. I do have an Icom 2340H that does the same. I have several other radios, 2M, 440 that don't merit mentioning. Article: 224755 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> Message-ID: Date: Fri, 26 May 2006 03:16:38 GMT Buck wrote: > Cecil Moore wrote: > >>But what about the people who say there's no energy in the >>reflected wave? Reckon how they sweep all those joules, >>whose energy must be conserved, under the rug? :-) > > with a jouler's brush? All kidding aside, whatever number of joules of energy are required to support the forward power and reflected power is provided by the source during the transient condition following power up. If the source power is 100 watts, the forward power is 200 watts, the reflected power is 100 watts, and the load power is 100 watts, all the joules per second needed to support that forward and reflected power was supplied by the source before steady-state was reached. Anything else would violate the conservation of energy principle. This is easily proven using a one second long lossless transmission line as a conceptual training aid for the uninitiated. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224756 of rec.radio.amateur.antenna From: "Nightline It's not" References: <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net> Subject: Re: One of these days. Very Soon now. Date: Fri, 26 May 2006 00:13:31 -0400 Message-ID: <959de$4476807f$d1cc576c$25796@snip.allthenewsgroups.com> "Radio Buff" wrote in message news:5erdg.5219$921.1628@newsread4.news.pas.earthlink.net... > You'll open your QST magazine to the Silent key section and Ham Radio will > be listed. > > sc Don't need to. Went to Dayton last weekend and only ONE-THIRD (1/3) of the total outdoor flea market spaces were taken, meaning occupied. Not only that, I was actually able to park in a lot at a strip mall just down the road from the Arena. I have been going to Dayton since 1980. I've missed going only 4 Years out of 26. This Year was the absolute smallest attendance I have ever seen. This alone should tell you something folks. I doubt that I'll be going again next Year, if ever again. Finally do not believe the "official" attendance figures. They lie thru their teeth worse than 5 pre-owned auto salesmen. Article: 224757 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: FIGHT? Here is another W8JI myth bone! Date: Thu, 25 May 2006 21:38:45 -0700 Message-ID: <127d1irculdn98c@corp.supernews.com> References: <21360-4473893B-1884@storefull-3257.bay.webtv.net> <127739l4kf0e73a@corp.supernews.com> <1279bvtn7e0p886@corp.supernews.com> <7cd972lnqpn8ir6p97q3ajb9f87nf0bv0a@4ax.com> <1148517119.544876.272330@j33g2000cwa.googlegroups.com> <1148553494.112985.49700@j73g2000cwa.googlegroups.com> <87jb72lnlmra471luaon4p3us57g42f1o0@4ax.com> <127bjves1rp06fa@corp.supernews.com> Sorry, this does not contain an example of a (time-varying) electric or magnetic field in the absence of the other. Such a condition is, in fact, impossible. Richard Clark wrote: >>>>> . . . >>>>> Richard's applications and illustrations do not push this boundary. In >>>>> fact, Ramo et. al distinctly offer the case of "electrostatic >>>>> shielding" and clearly support the separation of magnetic and electric >>>>> flux (fields). . . >>>> Can you direct me to where in the text they do so? All I've found is a >>>> short section (5.28) on "Electrostatic Shielding" where they explain >>>> that introducing a grounded conductor near two others will reduce the >>>> capacitive coupling between them. Obviously this will alter the local >>>> E/H ratio, but in no way does it allow an E or H field to exist >>>> independently, even locally, let alone at any distance. >>> Hi Roy, >>> >>> Article 5.12 "Circuit Concepts at High Frequencies or Large >>> Dimensions" >>> >>> Figure 5.28(a) shows a complete shielding. Of course this is entirely >>> electric, and arguably magnetic. However, magnetic flux can penetrate >>> thin shields, electric flux cannot. We've been talking about *time-varying* fields, and must have forgotten to explicitly state that qualification. The figure in question deals with static fields. Time-varying electric flux can indeed penetrate thin shields of finite conductivity, although the E/H ratio within the shield is very small. If a shield could block time-varying electric fields, the time-varying magnetic field which remained would create an electric field. A time-varying magnetic fields creates a time-varying electric field and vice-versa; this is dictated by Maxwell's equations. The answer to question 4.06d in Ramo, et al, "Can a time-varying field of any form exist in space without a corresponding electric field? Can a time-varying electric field exist without the corresponding magnetic field?" is no. A gapless shield made of a perfect conductor of any thickness will completely block both electric and magnetic fields. >>> >>> This is part and parcel to the world of isolated and shielded >>> circuits. The electrostatic shields are as effective as they are >>> complete in their coverage. Their contribution is measured in mutual >>> capacitance between the two points being isolated. With a drain wire >>> to ground, and a low enough Z in that wire, then that mutual >>> capacitance tends towards zero (however, near zero is a matter of >>> degree as I've offered in past discussion). >>> >>> Figure 5.28(a) shielding is quite common in medical circuit design, >>> and mutual capacitance does equal zero; and yet signals and power pass >>> in and out through magnetic coupling. Isolated relays are a very >>> compelling example of magnetic transparency in the face of total >>> electric shielding. The mutual capacitance at DC equals zero. Time-varying electric fields penetrate the shield if it's thin in terms of skin depth. >>> Magnetic shielding operates through reflection or dissipation >>> (absorption loss due to eddy currents). This loss is a function of >>> permeability µ. Unfortunately, permeability declines with increasing >>> frequency, and with declining field strength. Basically, all metals >>> exhibit the same characteristic µ above VLF; hence any appeal to >>> "magnetic materials" used to build antennas is specious. This is not true. Metals do indeed exhibit varying permeabilities at RF and above. This can be illustrated by a number of means, a common one being the efficacy of a powdered iron core. Electric field shielding also operates through reflection and dissipation. Permeability affects both, because of its effect on material wave impedance and skin depth. >>> This is not to say the magnetic shield is ineffective, merely derated >>> seriously from what might be gleaned through poor inference by reading >>> µ values from tables. Permeability does indeed change with frequency for a variety of reasons. Consequently, some intelligence (and often measurement or guesswork) has to be used to determine what it will be at the frequency in question. >>> However, it is quite obvious that transformer inter stage shielding >>> and the faraday shield found in AM transmitters is not seeking to >>> optimize this attenuation, far from it. Thus the degree in isolation >>> is found in the ratio of the mutual capacitance between the two points >>> before and after shielding; and the attenuation in magnetic flux >>> induction introduced between the two circuits after shielding. >>> >>> Returning to Ramo, et. al, the introduction of a partial shield. >>> Figure 5.28(c) is effective insofar as its ability to reduce mutual >>> capacitance. Indeed it is. This is not, however, an example of a (time-varying) magnetic or electric field existing in isolation. I readily agree that a static electric or magnetic field can exist in isolation from the other, as I'm sure all other participants to this discussion do. But not time-varying ones. You can greatly change the E/H ratio, but you can't make it zero or infinite. And whatever you do will have only a local effect -- the ratio will rapidly approach the intrinsic Z of the medium as you move away from the anomaly which modified the ratio. Rapidly, that is, in terms of wavelength -- it can be quite a physical distance at very low frequencies. Roy Lewallen, W7EL Article: 224758 of rec.radio.amateur.antenna From: Roger Subject: Re: ARS License Numbers Message-ID: References: <1148005814.174874.234520@38g2000cwa.googlegroups.com> <446e70b0$0$1010$39cecf19@news.twtelecom.net> <1148088937.210792.29680@38g2000cwa.googlegroups.com> <1148279770.237761.281080@i40g2000cwc.googlegroups.com> <44750879$0$6150$39cecf19@news.twtelecom.net> Date: Fri, 26 May 2006 01:33:49 -0400 On Wed, 24 May 2006 20:29:28 -0500, Tom Ring wrote: >Roger wrote: > > >> There are few people who can type that fast. However on CW you type >> your response while listening to the other station so the transmission >> speed can be well above your typing speed. >> >> I can count on the fingers of one hand the number of people I've met >> in school and industry who could even approach that 100 wpm. >> The old electric portables used to jam the keys at much over 60 while >> the "selectric" could go a fair amount faster. When in college my >> daughter wore out one of those and she could out type it. > >My father was NY state champ at over 100 wpm on a manual typewriter in >about 1940. I always figured Bucky the milkman must have been my real >father, since I was at 15 wpm before typing class, and 12 after a year >of it. I still type with 4 fingers, and have to use my eyes to figure >where they should go. And I have typed for a living for the last 30+ >years. :) If I have to look at the keyboard I'm in trouble. My fingers know where the keys are, but I don't. <:-)) If I'm on the telephone and taking notes it'd be faster to use a pencil. OTOH I can at least read my typing. I was net control for a weather watch net with tornado warnings out all around us (Lower Michigan). When I did the summary after the net I realized I need a head set with VOX built in so I can have both hands free. When I was a kid I bought a typing book, borrowed an old mechanical type writer and taught myself. It really didn't take all that long. I'd guess It took about the same time to get to 60 WPM on a mill as it did 20 on a key. My wife remarked that having worked in clerical and administration for the state she knew a number of people who could type 100 WPM. I asked if that was mistake free as corrections take time. It turned out they were considerably slower when mistakes were taken into account. OTOH when I was a sysadmin for a large corporation one of the system admins could type so fast the keyboard buzzed. You could watch the characters flow across the screen and in both directions. If he made a mistake it might take him two words to recognize it, go back and retype. I think he still was making over 100 WPM. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com > >tom >K0TAR Article: 224759 of rec.radio.amateur.antenna From: gsm@mendelson.com (Geoffrey S. Mendelson) Subject: Re: ARS License Numbers Date: Fri, 26 May 2006 07:21:03 +0000 (UTC) Message-ID: References: <1148005814.174874.234520@38g2000cwa.googlegroups.com> <446e70b0$0$1010$39cecf19@news.twtelecom.net> <1148088937.210792.29680@38g2000cwa.googlegroups.com> <1148279770.237761.281080@i40g2000cwc.googlegroups.com> <44750879$0$6150$39cecf19@news.twtelecom.net> Roger wrote: >>> I can count on the fingers of one hand the number of people I've met >>> in school and industry who could even approach that 100 wpm. >>> The old electric portables used to jam the keys at much over 60 while >>> the "selectric" could go a fair amount faster. When in college my >>> daughter wore out one of those and she could out type it. My wife and son can both type, error free at about that rate. I took a typing course in the summer when I was in high school and passed the 10wpm error free test. I think in my case it was 10wpm and at least one word error free :-) My first wife's sister was able to type faster than an IBM selectric typewriter (165wpm) error free. She won awards and contests for it. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ Article: 224760 of rec.radio.amateur.antenna From: Helmut Wabnig <...._.--_.-_-..._-._.._--.@.-_---_-._*_.-_-> Subject: Re: Smith Chart inventor Date: Fri, 26 May 2006 09:55:05 +0200 Message-ID: <3tcd72heivlt7hvgrb6p1qpuljokc9ag82@4ax.com> References: <445138e4$0$1007$39cecf19@news.twtelecom.net> On Fri, 28 Apr 2006 19:55:19 -0400, Dave wrote: > >That was 48 years ago. I wish I could remember everything I've >forgotten. Heck! I wish I could remember 10% of it!!!! Thanks for that. Now I know, I am not alone. w. -- Too much space is not good for my health, said the astronaut and returned to Earth. Article: 224762 of rec.radio.amateur.antenna Date: Fri, 26 May 2006 07:06:38 -0500 From: Tom Ring Subject: Re: What happens if you pipe the output of one radio in to 2 amps? References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> Message-ID: <4476ef4e$0$1013$39cecf19@news.twtelecom.net> Yuri Blanarovich wrote: >> >>As far as replying in kind, I've been reading your posts for quite a >>while, and I haven't noticed that you withhold any criticisms. >> >>If the only errors you made were typos, this crowd wouldn't have a problem >>with you. >> >>And I know when I am out of my depth, and to keep my mouth firmly shut, as >>apparently you do not. >> >>tom >>K0TAR > > > Typical response. Just read what happened in this thread. > Look at what I wrote, look at what you responded. > I am not criticizing, I respond to crap and personal attacks in kind, not > very nice, but I do not need to put up with snotty remarks and personal BS. > Looks like hurlers don't like when one responds in kind. > If discussion is about technical matters, I provide help where I can or feel > like. If jerk doesn't like it and comes riding high horse, then I get on my > horse too, which happened with W8JI (we go way back) and now with you. > I provided my opinion on 2 PAs to 2 ANTs, you twisted it and snapped GURU > crap on it, Richard Clark was right behind you. I hate to see you when you > are out of your depth. Now you come on with lecture about "crowd having > problem with me"? > You discuss technical matters in a civil way, I respond in kind, you pull > out snotty crap, and I don't take it. Mark it down and next time if you want > do the technical exchange I am open for dialog. > What you want me to do to be "nice"? Accept the "truth" that current along > the loading coil is ALWAYS the same, that shield IS the antenna, that > electrostatic shield can't possibly work, that antenna is not an antenna? > Where I come from, we fight for truth and if needed give life for it. If you > want me to bow to false teachings, or to take crap, look somewhere else. > So you want to try to be nice and discuss the problems with intermods > between two PAs feeding two antennas or play W8JI? I can also engage on > Wilkinson's hybrids, I use them. > Let's stay with the subjects of this NG and keep the crap for the toilets. Thank you for proving my points. tom K0TAR Article: 224763 of rec.radio.amateur.antenna From: Buck Subject: Re: Brainteaser Message-ID: <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> References: <20319-44762304-243@storefull-3258.bay.webtv.net> Date: Fri, 26 May 2006 08:09:02 -0400 On Fri, 26 May 2006 03:16:38 GMT, Cecil Moore wrote: > >If the source power is 100 watts, the forward power is 200 >watts, the reflected power is 100 watts, and the load power >is 100 watts, all the joules per second needed to support >that forward and reflected power was supplied by the source >before steady-state was reached. Anything else would violate >the conservation of energy principle. > >This is easily proven using a one second long lossless >transmission line as a conceptual training aid for the >uninitiated. I gathered that from an earlier post, but I think the confusion comes in the second second, doesn't it? 100 watts of power is generated >from the generator for two seconds. the first second, 100 watts travels to the antenna and only 100 watts is in the transmission line. Then for the second second, 100 forward watts is moving towards the antenna and 50 reflected watts are returning to the transmitter for a total of 150 watts in the transmission line? Of course, since the transmitter isn't matched to the antenna, the reflected power is reflected again for 25 watts being reflected back to the antenna bringing the power from 100 forward watts to 125 watts (the reason power meters go up in wattage when SWR rises) thus the antenna reflects 62.5 watts which adds to the 125 for a total of 187.5 watts in the transmission line. Sooner or later one will have a meltdown that will make Chernoble look like a firecracker compared to a fireworks display. lol -- 73 for now Buck N4PGW Article: 224764 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> <4476ef4e$0$1013$39cecf19@news.twtelecom.net> Subject: Re: What happens if you pipe the output of one radio in to 2 amps? Message-ID: <4pCdg.166$CP6.98@fe08.lga> Date: Fri, 26 May 2006 08:20:38 -0400 "Tom Ring" wrote in message news:4476ef4e$0$1013$39cecf19@news.twtelecom.net... > Yuri Blanarovich wrote: >>> > Thank you for proving my points. > > tom > K0TAR Thank you for displaying your mental capabilities. Enjoy unloading your personal digs! 73 Yuri, K3BU Article: 224765 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> Message-ID: Date: Fri, 26 May 2006 12:41:45 GMT Buck wrote: > I gathered that from an earlier post, but I think the confusion comes > in the second second, doesn't it? 100 watts of power is generated > from the generator for two seconds. the first second, 100 watts > travels to the antenna and only 100 watts is in the transmission line. > Then for the second second, 100 forward watts is moving towards the > antenna and 50 reflected watts are returning to the transmitter for a > total of 150 watts in the transmission line? Of course, since the > transmitter isn't matched to the antenna, the reflected power is > reflected again for 25 watts being reflected back to the antenna > bringing the power from 100 forward watts to 125 watts (the reason > power meters go up in wattage when SWR rises) thus the antenna > reflects 62.5 watts which adds to the 125 for a total of 187.5 watts > in the transmission line. Sooner or later one will have a meltdown > that will make Chernoble look like a firecracker compared to a > fireworks display. lol Actually, the forward power levels off at 200 watts during steady- state. The reflected power levels off at 100 watts. 300 joules of energy exist that have been sourced but not dissipated in the load. 300 joules are exactly what the forward wave and reflected wave need to support their existence. Here's the brainteaser configuration: 100W-SGAT---one second long lossless 50 ohm feedline---291.42 ohm load The 'SGAT' is a signal generator equipped with a super fast auto-tuner that re-reflects all the reflected power back toward the load so there are no losses at the source end. The only losses in the entire system are in the 291.42 ohm load which, to make the math easier, was chosen for a power reflection coefficient of 0.5, i.e. half the incident power is reflected at the load. I will generate an EXCEL spreadsheet today that will give a second by second summary of the powers and total energy. In the meantime, here is a more simplified version of the brainteaser. 100W-SGCL---one second long lossless 50 ohm feedline---291.42 ohm load The 'SGCL' is a signal generator equipped with a circulator and 50 ohm resistor. During steady-state, half the generated power is dissipated in the load and half in the circulator resistor. There are no re- reflections at the source. During the 1st second, the source supplies 100 joules into the feedline. There is no dissipation either in the load or circulator resistor. During the 2nd second, the source supplies another 100 joules into the feedline, 50 joules of which are converted to heat in the load and 50 joules of which are reflected from the load as 50 watts of reflected power. At the end of the 2nd second, the feedline contains 150 joules of energy. During the 3rd second, steady-state is reached. Of the 100 watts sourced, 50 watts are dissipated in the load and 50 watts are dissipated in the circulator resistor. At the end of the 3rd second, the source has generated 300 joules, 100 of which have made it to the load, and 50 of which have made it to the circulator resistor. 300-100-50 = 150 joules stored in the feedline. 100 joules are stored in the 100W forward wave. 100 joules/sec = 100W 50 joules are stored in the 50W reflected wave. 50 joules/sec = 50W This conservation of energy works for any length feedline. If the feedline were one microsecond long instead of one second long, there would be 150 microjoules stored in the feedline, 100 microjoules in the forward wave and 50 microjoules in the reflected wave. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224766 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: What happens if you pipe the output of one radio in to 2 amps? References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> <4476ef4e$0$1013$39cecf19@news.twtelecom.net> <1148646180.019541.169980@u72g2000cwu.googlegroups.com> Message-ID: Date: Fri, 26 May 2006 12:50:14 GMT w8ji@akorn.net wrote: > I'm really sorry readers are subjected to this sort of thing in a > technical forum. Please don't associate me with the ranting. Pot - Kettle, Kettle - Pot. Here's one of your rantings. W8JI wrote: > I feel sorry for anyone who has to deal with you on a daily basis. > No wonder your wife split. Your technical content is noted. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224767 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> Message-ID: Date: Fri, 26 May 2006 12:59:59 GMT Dave wrote: > is that line 1 second long, or 1/2 second long?? a 1 second long line would > take 2 seconds worth of energy from the generator before the reflection > returned to let it know the line is terminated. this is of course very > important if you are measuring lines with tdr's where you can really see > those returned waves, of course the time it takes them to get back to the > tdr is double the one-way travel time... mess it up and you are looking for > faults twice as far down the line as you calculate. The line is 1 second long. The source is generating 100 watts. So the number of joules generated starting at t=0 is 100N where N is the total number of seconds. At the end of 30 seconds, the generator will have sourced 3000 joules which must be conserved. I will generate an EXCEL spreadsheet at work today and post it to my web page when I get home. It will cover the first 30 seconds in 1 second increments. It will show that of the 3000 joules sourced by the generator during that first 30 seconds, only 2700 joules have reached the load. The other 300 joules are contained in the 200W forward wave and 100W reflected wave. (200 watts)(one second) = 200 joules in the forward wave (100 watts)(one second) = 100 joules in the reflected wave 200 joules + 100 joules = 300 joules not delivered to the load -- 73, Cecil http://www.qsl.net/w5dxp Article: 224768 of rec.radio.amateur.antenna From: Buck Subject: converting from dipole/inverted vee to beam Message-ID: Date: Fri, 26 May 2006 09:21:59 -0400 I have a wire dipole and an inverted Vee each cut to resonance on a desired frequency. I would like to add a reflector and/or a director (one at the time) to make each one a beam. Will adding the reflector and/or director change the resonant frequency, or just the impedance? Thanks Buck n4pgw -- 73 for now Buck N4PGW Article: 224769 of rec.radio.amateur.antenna From: "hasan schiers" Subject: Re: converting from dipole/inverted vee to beam Date: Fri, 26 May 2006 08:40:08 -0500 Message-ID: References: Both, in all likelyhood. "Buck" wrote in message news:g00e72lh8n694shm5fh3bnkva8ovu76koc@4ax.com... >I have a wire dipole and an inverted Vee each cut to resonance on a > desired frequency. I would like to add a reflector and/or a director > (one at the time) to make each one a beam. Will adding the reflector > and/or director change the resonant frequency, or just the impedance? > > Thanks > Buck > n4pgw > > -- > 73 for now > Buck > N4PGW Article: 224770 of rec.radio.amateur.antenna From: Buck Subject: Re: Brainteaser Message-ID: <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> Date: Fri, 26 May 2006 09:44:55 -0400 On Fri, 26 May 2006 12:41:45 GMT, Cecil Moore wrote: >Buck wrote: All this technical detail is interesting, but in the last thirty years of hamming, I have taken note to know the following: My radio is most happy when matched with an SWR of less than 1.8:1 If my antenna exceeds that, either adjust it or use a tuner The higher I raise my antenna, the better. A yagi works better than a dipole given the same height and direction. A dipole works better to the west than a beam pointed north. i would rather have a high gain antenna than a high power amp. Most importantly: If band conditions permit, I can talk across the ocean on an antenna with a 30 db loss, but with certain band conditions, even a 30 db gain antenna won't make the contact! I can't tell you how many joules are in my coax, but, if you ask, I can tell you how many jewels are in my logbook. :) -- 73 for now Buck N4PGW Article: 224771 of rec.radio.amateur.antenna From: Buck Subject: Re: converting from dipole/inverted vee to beam Message-ID: <8k1e72pr1atcssce577vm6bn842kc61pgj@4ax.com> References: Date: Fri, 26 May 2006 09:45:58 -0400 On Fri, 26 May 2006 08:40:08 -0500, "hasan schiers" wrote: >Both, in all likelyhood. > >"Buck" wrote in message >news:g00e72lh8n694shm5fh3bnkva8ovu76koc@4ax.com... >>I have a wire dipole and an inverted Vee each cut to resonance on a >> desired frequency. I would like to add a reflector and/or a director >> (one at the time) to make each one a beam. Will adding the reflector >> and/or director change the resonant frequency, or just the impedance? >> >> Thanks >> Buck >> n4pgw >> >> -- >> 73 for now >> Buck >> N4PGW > I guess I'll have to try it to see what happens. Thanks -- 73 for now Buck N4PGW Article: 224772 of rec.radio.amateur.antenna From: "Cecil Moore" References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> Subject: Re: Brainteaser Message-ID: <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> Date: Fri, 26 May 2006 14:15:33 GMT "Buck" wrote: > I can't tell you how many joules are in my coax, but, if you ask, I > can tell you how many jewels are in my logbook. :) This is not aimed at people who don't care about such things. This is aimed at people who do care about such things especially those who are disseminating false technical information about such things. Some say that since there's 100 watts in and 100 watts out during steady-state, there's nothing left over for the reflected waves. They apparently forgot about the time immediately following power up when there was 100 watts in and less than 100 watts out. -- 73, Cecil, W5DXP Article: 224773 of rec.radio.amateur.antenna From: "Cecil Moore" References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> <4476ef4e$0$1013$39cecf19@news.twtelecom.net> <1148646180.019541.169980@u72g2000cwu.googlegroups.com> <1148654506.771091.181630@g10g2000cwb.googlegroups.com> Subject: Re: What happens if you pipe the output of one radio in to 2 amps? Message-ID: Date: Fri, 26 May 2006 14:52:59 GMT wrote: > > Cecil Moore wrote: > > Pot - Kettle, Kettle - Pot. > > You're absolutely right Cecil. Someone needs to tell W8JI that there's a nice person forging postings from his ISP address. :-) -- 73, Cecil, W5DXP Article: 224774 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: converting from dipole/inverted vee to beam Date: Fri, 26 May 2006 08:32:25 -0700 Message-ID: <127e7sf1v8kjee8@corp.supernews.com> References: Jerry Martes wrote: > "Buck" wrote in message > news:g00e72lh8n694shm5fh3bnkva8ovu76koc@4ax.com... >> I have a wire dipole and an inverted Vee each cut to resonance on a >> desired frequency. I would like to add a reflector and/or a director >> (one at the time) to make each one a beam. Will adding the reflector >> and/or director change the resonant frequency, or just the impedance? >> >> Thanks >> Buck >> n4pgw >> >> -- >> 73 for now >> Buck >> N4PGW > > Hi Buck > > Isnt Resonance defined as the frequency where the Impedance has *no* > reactance? Wouldnt that imply that the resonant frequency of the antenna > will always change if its impedance changes? > Can you *ever* change one without changing the other? You're correct about the definition of resonance. Buck's statement would have made more sense if it the last words were "just the resistance", and that's likely what he meant. Sure, you can change the impedance without changing the resonant frequency -- a transformer will do that, for example. At resonance, the resistance will simply be a different value. But to answer Buck's question, adding another element will almost certainly change both the resistance and reactance at the feedpoint, and therefore the resonant frequency. Roy Lewallen, W7EL Article: 224775 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <15322-44748CC5-24@storefull-3251.bay.webtv.net> <8X2dg.249$LO3.138@fe11.lga> <4475127b$0$1010$39cecf19@news.twtelecom.net> <44764307$0$1016$39cecf19@news.twtelecom.net> <4476ef4e$0$1013$39cecf19@news.twtelecom.net> <1148646180.019541.169980@u72g2000cwu.googlegroups.com> <1148654506.771091.181630@g10g2000cwb.googlegroups.com> Subject: Re: What happens if you pipe the output of one radio in to 2 amps? Message-ID: Date: Fri, 26 May 2006 12:12:22 -0400 So stick to technical questions and answers, keep comments about someone's wife, license class, foaming, etc. to yourself. You start the crap and then scream when "favor" is returned. Just go back and look who initiates that, instead of answers to questions in question. Bada BUm wrote in message news:1148654506.771091.181630@g10g2000cwb.googlegroups.com... > > Cecil Moore wrote: >> Pot - Kettle, Kettle - Pot. Here's one of your rantings. >> >> W8JI wrote: >> > I feel sorry for anyone who has to deal with you on a daily basis. >> > No wonder your wife split. >> >> Your technical content is noted. >> 73, Cecil http://www.qsl.net/w5dxp > > You're absolutely right Cecil. > > There is no reason for anyone, including me, to personally attack > others or to rant and rave like a lunatic. > > It absolutely ruins techincal forums when people get too personal, no > matter who does it. I think that is a major reason why this newsgroup > fell from being very popular to barely used. > > 73 Tom > Article: 224776 of rec.radio.amateur.antenna From: "Jerry Martes" References: <127e7sf1v8kjee8@corp.supernews.com> Subject: Re: converting from dipole/inverted vee to beam Message-ID: Date: Fri, 26 May 2006 16:45:22 GMT "Roy Lewallen" wrote in message news:127e7sf1v8kjee8@corp.supernews.com... > > > Jerry Martes wrote: >> "Buck" wrote in message >> news:g00e72lh8n694shm5fh3bnkva8ovu76koc@4ax.com... >>> I have a wire dipole and an inverted Vee each cut to resonance on a >>> desired frequency. I would like to add a reflector and/or a director >>> (one at the time) to make each one a beam. Will adding the reflector >>> and/or director change the resonant frequency, or just the impedance? >>> >>> Thanks >>> Buck >>> n4pgw >>> >>> -- >>> 73 for now >>> Buck >>> N4PGW >> >> Hi Buck >> >> Isnt Resonance defined as the frequency where the Impedance has *no* >> reactance? Wouldnt that imply that the resonant frequency of the >> antenna will always change if its impedance changes? >> Can you *ever* change one without changing the other? > > You're correct about the definition of resonance. > > Buck's statement would have made more sense if it the last words were > "just the resistance", and that's likely what he meant. > > Sure, you can change the impedance without changing the resonant > frequency -- a transformer will do that, for example. At resonance, the > resistance will simply be a different value. > > But to answer Buck's question, adding another element will almost > certainly change both the resistance and reactance at the feedpoint, and > therefore the resonant frequency. > > Roy Lewallen, W7EL Hi Roy I'm not qualified to enter into a theory discussion with you. But, I'd expect the introduction of a nearly half wave long comductor into the near vicinity of an antenna that has a purely resistive Terminal Impedance (Resonant) will change the Terminal Impedance of the new antenna which is the combination of the two. I would have considered that transformer doesnt actually change the antenna's Terminal Impedance (Resonance) the transformer converts the antenna's impedance *at a new location*. So, I'd expect the antenna's "resonance" to be defined by its "impedance". I've considered that any R+/-jX can be Transformed to an impedance thats purely resistive. But, with antennas, thats a matching situation, while the antenna's terminal impedance remains reactive. Jerry Article: 224777 of rec.radio.amateur.antenna Message-ID: <5nojk3-c0p.ln1@mail.specsol.com> From: jimp@specsol.spam.sux.com Subject: Re: converting from dipole/inverted vee to beam References: Date: Fri, 26 May 2006 17:05:02 GMT Buck wrote: > I have a wire dipole and an inverted Vee each cut to resonance on a > desired frequency. I would like to add a reflector and/or a director > (one at the time) to make each one a beam. Will adding the reflector > and/or director change the resonant frequency, or just the impedance? > Thanks > Buck > n4pgw > -- > 73 for now > Buck > N4PGW Both most likely. Download the demo eznec and model it; www.eznec.com. After you've used it a few times, you'll want to buy the full version. Nope, no connection with eznec. It has saved me a lot of time, effort, and cut up wire though. -- Jim Pennino Remove .spam.sux to reply. Article: 224779 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> Message-ID: Date: Fri, 26 May 2006 17:46:56 GMT Reg Edwards wrote: > Let Zo = 100 ohms. For what range of frequencies is the above true? -- 73, Cecil http://www.qsl.net/w5dxp Article: 224780 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: FIGHT? Here is another W8JI myth bone! Date: Fri, 26 May 2006 11:10:28 -0700 Message-ID: <127eh4knvgcfo33@corp.supernews.com> References: <1279bvtn7e0p886@corp.supernews.com> <7cd972lnqpn8ir6p97q3ajb9f87nf0bv0a@4ax.com> <1148517119.544876.272330@j33g2000cwa.googlegroups.com> <1148553494.112985.49700@j73g2000cwa.googlegroups.com> <87jb72lnlmra471luaon4p3us57g42f1o0@4ax.com> <127bjves1rp06fa@corp.supernews.com> <127d1irculdn98c@corp.supernews.com> Richard Clark wrote: > On Thu, 25 May 2006 21:38:45 -0700, Roy Lewallen > wrote: > >> Time-varying electric flux can indeed penetrate thin >> shields of finite conductivity, although the E/H ratio within the shield >> is very small. > >> A gapless shield made of a perfect conductor of any thickness will >> completely block both electric and magnetic fields. > > Hi Roy, > > Given the vast gulf that separates these two observations above, and > the oblique reply in general that does not flow from your previous > question that I responded to.... It seems you are answering a topic I > have not entered into, or restating what I've already offered. Sorry, once again I miss your point. I maintain that time-varying electric and magnetic fields cannot exist independently, while you claim that they can. Tom and I asked for an example of a case where they do, and your response did not contain such an example. Roy Lewallen, W7EL Article: 224781 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Brainteaser Date: Fri, 26 May 2006 11:16:32 -0700 Message-ID: <127ehg13fkl8gcf@corp.supernews.com> References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> Reg Edwards wrote: > I've lost the original question. > > But there is a lossless transmission line 1 second long. > With a velocity factor of 1.0 it is 30,000 kilometres long. > > Let Zo = 100 ohms. > Let applied volts = 100 VDC. > Let terminating resistance be 100 ohms. > > Line Inductance = 10,000 Henrys. > Line Capacitance = 1 Farad. > > Under steady state conditions - > Line current = 1 amp. > Energy stored in inductance = Sqr(I)*L/2 = 5000 Joules. > > Volts across capacitance = 100 volts. > Energy stored in capacitance = SqrV)*C/2 = 5000 Joules. > > Total energy stored = 10, 000 Joules = 10,000 watt.seconds. > > Which has nothing whatsoever to do with all this nonsense about > reflections. Note that energy in inductance equals energy in > capacitance. Yep, you don't have to mess with those pesky reflections when the line is terminated in a load equal to its characteristic impedance. Then the problem reduces to the trivial one you've posed. Simple problem, simple solution. Roy Lewallen, W7EL Article: 224782 of rec.radio.amateur.antenna From: Bruce in Alaska Subject: Re: Yacht Rf ground and radials References: <447311d0_1@news.iprimus.com.au> <9pjc72l61nevr23547h77bq2vdf86thdiu@4ax.com> Message-ID: Date: Fri, 26 May 2006 19:08:20 GMT In article , chuck wrote: \> > Hello Gary, > > Although I'm not advocating "radials" or any other marine HF grounding > approach, I am trying to understand the reasoning used by those who do > advocate. I've tried to set up instrumentation that would allow > comparative measurements of alternative "ground" properties for yachts, > but the problems involved have been overwhelming. I think I understand > why the world is not awash in empirical data in this area, especially > compared to what is available for land-based verticals. > > > First, radials on a boat are not usually better than a good ground to > > seawater. > > I think the word "radials" in this thread ought to be in quotes, since > we're really not talking about conventional symmetrical radials from > which radiation is substantially canceled. As you point out, the > "radials" being discussed in this thread are simply a horizontal part of > the radiating antenna and not really radials at all. What you need to understand is just what kind of antenna are you trying to describe, here as a MF/HF Marine Antenna? Are you thinking a Marconi, Vertical Dipole, Offcenter Feed Marconi, or just what? The standard MF/HF Marine Antenna, usually is considered a Marconi, and that is what MOST both commercial and non-commercial MF/HF Marine antennas end up being. So lets discuss Marine Marconi Antennas, and what makes good ones and bad ones. Marconi Antennas are charactorized by 1/4 Lambda Vertical Radiating Element, sitting in close proximity to a LOW Impedance RF Ground System Perpendicular to the 1/4wave Vertical. In the MF/HF Marine enviorment we add a Tuner, Auto or Manual so as to be able to tune the Vertical to a 1/4 Wave Electrical Length and Resonance on each frequency that the vessel maybe required to use in the MF/HF Marine Frequency Bands, which cover 1.6Mhz to 25 Mhz in frequency. Ok now lets look at what the vertical is. A Backstay, a Whip, a Loaded Whip, a Loaded Whip with wire under it. It really doesn't matter, as they all will be tuned to resonance, in either 1/4Wave, or 3/4Wave by the tuner, against the impedance of whatever RF Ground is connected to the tuner. Hence the "Old RadioMans Addage", "If you have a Good RF Ground, anything will radiate a good signal, even a wet noodle, but even the best antenna will radiate poorly if it is working against a poor RF Ground." It is the RF Ground, that determines how WELL Marconi Antennas work. Always has, and always will. > > Having said that, I would welcome learning your basis for the > conclusion, and any info you can offer on how much better and in what > way. Do you have a measurement of the HF "ground resistance" provided by > seawater using a Dynaplate? Would your conclusion change for a vessel on > the Chesapeake where salinity is quite low? Ok, lets look at what RF Ground really means in MF/HF Marine Antenna Systems. Put on your "Bruce's Special RF Glasses" and look at you vessel, and lets see what the Marine enviorment really looks like to RF. Lets take a look at the wood or plastic hulled vessel over there, what DO WE SEE? Well, we see the vertical radiator, we see the salt water, we see the metal on the boat that is grounded electrically together, (bonded) we see the engine if it has one, we see the piping and wiring that is all connected electrically, or bonded to the engine, and nothing else. Now remember that for a Marconi Antenna, IT IS THE RF GROUND that determines the efficency of the system. What makes a good low impedance RF Gound? Large Flat area, perpendicular to the Radiator, very electrically conductive. Sounds just like Salt Water, doesn't it. Hmmmm, wonder why most really good systems use the WATER as the RF Ground? Dahhhh. Again, remember that we are looking for a LOW Impendance RF Ground that doesn't have much of a reactive component to it, so that it will be good just about anywhere in the 1.6- 25Mhz range. > > If you do use radials they need to be resonant which means they need > > to be Ľ wavelength long at each frequency of operation or they need to > > be tuned with a loading coil to make them resonant. The reason is that > > if they are not resonant you will get little current into them. Your > > antenna system will be unbalanced and being that the radials will > > usually be closer to other wires etc. on the boat they will couple > > into them before they couple to the sea. That will make the tuner coax > > and control cables radiators as well, because of the higher impedance > > of the radials. > > We don't seem to require that the backstay (or whatever vertical > radiator we are using) be a physical 1/4 wavelength when we use a tuner. > Why would we impose that requirement on the horizontal part of the > radiating system? Isn't the famous 100 square feet of copper approach > analytically equivalent to a nonresonant "radial"? > Ok, now lets look at what we have to use to build a good LOW Impedance RF Ground with what we see using "Bruce's Special RF Glasses". One thing to think about, Do we really want to make a direct connection to the WATER, for our RF Ground, and if so do we want to make that Direst Connection a DC CONNECTION? This question is where "Elctrolysis" comes into play, and is beyound the scope of this lecture, so for convience lets assume we want NO DC Path to the WATER. So how do we then couple the RF to the water effectivly? Well, we use a Capacator, and a capacitor is made up of "Two Plates seperated by an insulator. Our capacitor has one plate as the Salt Water, and the insulator is the Wood or Plastic Hull, and the other plate we need to build out of what we have aboard that we can see with our "Special Glasses". Now what are the factors that increase the capacative coupling in a capacator? Plate surface area, and plate speration, so we want as much surface area as we can get, as close to the Salt Water, as we can get. The higher the coupling, the lower the impedance of the RF Gound System, and the BETTER the antenna system wiull function. > It is true that proximity of the horizontal radiator to other wiring can > cause problems, and this may be an unequivocal disadvantage to the > approach. Of course, an entire sailboat is in the reactive near-field > region of the vertical radiating element regardless of the "ground" used > and so the coupling issue is a matter of degree. > Not a real big issue here. Near field is basically unimportant in Marconi Antenna Systems, except for Near Field Grounded Verticals within a few feet of the Vertical Antenna. > > Chuck > NT3G End of Lecture Part 1 MF/HF Marine Radio Antenna System Design / Simplified It's the Ground, dummy, the RF Ground........ Bruce in alaska an Old MF/HF Marine RadioMan from way back..... -- add a <2> before @ Article: 224783 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <98adnTStr6XO2erZRVnyjA@bt.com> Message-ID: <83Jdg.41395$Lm5.284@newssvr12.news.prodigy.com> Date: Fri, 26 May 2006 19:55:48 GMT Reg Edwards wrote: > If you ask silly questions you can expect silly answers. > > Are you looking for a reason to introduce your irrelevant reflections > again. No, just trying to correlate your example to mine. In your example, how long does it take from power up for the load to accept 100 joules/second? -- 73, Cecil http://www.qsl.net/w5dxp Article: 224784 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <127ehg13fkl8gcf@corp.supernews.com> Message-ID: Date: Fri, 26 May 2006 19:57:19 GMT Roy Lewallen wrote: > Yep, you don't have to mess with those pesky reflections when the line > is terminated in a load equal to its characteristic impedance. Which begs the question of what is to be done when "those pesky reflections" exist in a mismatched system. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224785 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <127ehg13fkl8gcf@corp.supernews.com> Message-ID: Date: Fri, 26 May 2006 20:10:32 GMT Reg Edwards wrote: > It's the Devil which makes Cecil pose such loaded questions. It's only loaded with the conservation of energy principle, Reg. Here's a simple example. The SG-CR is a 50 ohm signal generator equipped with a circulator resistor to dissipate all reflected power incident upon the source. 200W SG-CR---one second long lossless 50 ohm line---291.42 ohm SWR is 5.83:1 rho^2 = 0.5 Steady-state forward power is 200 watts. Steady-state reflected power is 100 watts. The question is: After steady-state has been reached, how many joules of energy have been generated but have not been dissipated in the load resistor or circulator resistor? -- 73, Cecil http://www.qsl.net/w5dxp Article: 224786 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <1148673991.300212.15870@i39g2000cwa.googlegroups.com> Message-ID: Date: Fri, 26 May 2006 20:16:31 GMT K7ITM wrote: > Sigh. Yes, I believe you HAVE made a mistake in your calculations, > right at the beginning. C = tau/Z0 = 1/100 farad; L = tau*Z0 = 100 > henries. But of course, the concept is perfect. 100V, 1A, 100W, > E^2*C/2 = 50 joules stored in the capacitance. I^2*L/2 = 50 joules > stored in the inductance. The two are equal only for a termination > equal to the line Z0 of course. > > Too bad Cec doesn't understand that lossless line has unvarying Z0 as a > function of frequency from DC up, as long as TEM mode is supported. I do understand that. That's why Reg's 10,000 joules don't make any sense to me. Now if the Z0 was one ohm at DC, it would make sense for 100 volts to be able to supply 10,000 joules in one second. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224787 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <1148676148.656605.300060@g10g2000cwb.googlegroups.com> Message-ID: <%cKdg.267$VE1.248@newssvr14.news.prodigy.com> Date: Fri, 26 May 2006 21:14:35 GMT K7ITM wrote: > Actually, it was "200 watts forward, 100 watts reflected" -- but it > works the same way: 100 ohm line, 1 second long: source is DC > 200*sqrt(2) volts in series with 100 ohms. Load is such that it > absorbs 100 watts from that source: 100*(3 +/- sqrt(8)) ohms. About > 17.16 ohms works OK. Then the line voltage is 41.42V and the energy > stored in the 1/100F line capacitance is 8.579 joules, and the line > current is 2.414A and the energy stored in the 100H line inductance is > 291.421 joules. Total energy stored is 300 joules. As can be seen from http://www.qsl.net/w5dxp/1secsgcr.gif Do you think it's just a coincidence that 200 watts of forward power in a one second long line would require 200 joules and 100 watts of reflected power in a one second long line would require 100 joules for a total of 300 joules? > Now, I have no idea who it is that might be saying that there's no > energy stored in the fields in a line, so I really don't know what the > to-do is all about. Please read what W7EL says about forward and reflected power in his "food for thought" writings. In particular: "Some inventive people have supposed they can separate forward and reverse power with a circulator. That really sounds attractive, particularly with an open or short circuited load. In that condition, the forward and reverse powers are each 100 watts, yet the transmitter (or the transmitter voltage source) doesn't have to produce any power at all." What W7EL doesn't seem to realize is that the source produced the power in the forward and reverse power waves while the feedline was charging up during the transient period before the reverse power waves reached the source so there is bona fide energy in those waves. He also says there is no model for handling such yet one exists in detail in the magazine article on my web page. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224788 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <1148673991.300212.15870@i39g2000cwa.googlegroups.com> <1PSdnZTS3Iee8-rZnZ2dnUVZ8qWdnZ2d@bt.com> Message-ID: Date: Fri, 26 May 2006 21:17:29 GMT Reg Edwards wrote: > Damned decimal points. I just KNEW I had made a mistake somewhere > along the line. Now do you see why my question wasn't simple or loaded? I just wondered how you shoved 10,000 joules down a Z0=100 ohm feedline in one second using a fixed 100 volt source. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224789 of rec.radio.amateur.antenna From: Ken C Subject: Loose antenna base? Message-ID: Date: Fri, 26 May 2006 16:41:29 -0500 I am using screw-on antennas on my Ramsey DF rig. The threaded (female) barrels keep coming loose in the antenna tube -- where they appear to be locked by a groove and four tiny punches in the tube. I have tried solder, but it does not adhere. Any other suggestions? Ken KC2JDY Article: 224790 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <127e7sf1v8kjee8@corp.supernews.com> Subject: Re: converting from dipole/inverted vee to beam Message-ID: <3FKdg.56$Zb5.26@fe08.lga> Date: Fri, 26 May 2006 17:43:47 -0400 "Jerry Martes" wrote > So, I'd expect the antenna's "resonance" to be defined by its > "impedance". > Antenna resonance is defined by its element's electrical properties, "caused" by its physical properties/dimensions. In case of 3 el "conversion" from Inv Vee, you have to picture elements as a tuned circuits. If they are spaced within a fractions of a wavelength, they have mutual impedance, affecting each other. As you start adding elements, they add capacitance to the system and lower the overall resonant frequency and impedance. Single Dipole is around 75 ohms, 3 el. Yagi around 30 ohms. The more elements you add, the more sensitive the design is and requires more prunning for optimum performance. So just slapping elements to Inv Vee dipole will not produce optimized antenna. EZNEC, 4NEC2, MMANA are an excellent tools to demonstrate that and to optimize the design, give you dimensions and impedance and understanding behavior of antennas, give current distribution in elements, plots of impedance, gain and other parameters. -- Yuri Blanarovich, K3BU, VE3BMV Article: 224791 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <1148676148.656605.300060@g10g2000cwb.googlegroups.com> Message-ID: Date: Fri, 26 May 2006 22:18:33 GMT Ian White GM3SEK wrote: > What I said was that there are commonly multiple methods to analyse the > same problem, but that all correct methods MUST agree, because they are > only different views of the same physical reality. That attitude is certainly an improvement from the earlier labeling of an alternate valid analysis as "Gobbledygook". -- 73, Cecil http://www.qsl.net/w5dxp Article: 224792 of rec.radio.amateur.antenna From: "Steve N." Subject: Re: Grounding a metal roof Date: Fri, 26 May 2006 17:26:55 -0500 Message-ID: References: <1148272981_5573@sp6iad.superfeed.net> "Sal M. Onella" wrote in message news:J9adg.27540$QP4.14620@fed1read12... > > "Steve N." wrote in message > news:e52gqp$tuu$1@avnika.corp.mot.com... > > > < snip > > > > Another concern (though I have no experience with roofs, just autos) is > the > > intermitent contact (as opposed to a rectifying junction, as Richard > points > > out) that is possible. If there are joints that can make and break, say > in > > the wind, you may have noise generated. Chain-link fences would be > > susceptable to this as well. Wether or not it produces noise in your > > receiver, I would think, is rather unlikely, unless you were somewhere > near > > a broadcast station or another ham for reasons described next. > > It's mostly a problem if you are running two or more rigs at the same > time. Your 2M packet rig could interfere with your 2M ragchew. Yes, the "offending" transmitter needs to be in close proximity so that 1- the offending junction(s) are sufficiently illuminated by it to produce strong enough sidebands to be a problem in the offended receiver. 2- The offended receiver has to be close enough to be offended by the levels involved. > > The Navy, for whom I work, bonds (or isolates) everything ... > Every spark, no matter how small, is an RF generator. It isn't necessarily a spark, in fact probably infrequently sparks unless you're dealing with higher power. It goes like this. Both sides of the offending junction are picking up RF. They are conductors, so there are RF currents flowing. When there are RF currents flowing you have radiation. As the junction opens and closes, the RF currents change. When the junction is making contact, current can flow - when disconnected, current can not flow (pretty much; let's not get into the capacitance thing). The changes in current with a noisy contact will mimic the "noise" of that contact. The radiation will therefore mimic that noise also. That noisy radiation will sum with the original, desired radiation. This, in effect, modulates the radiated signal after it leaves the transmitter. If it is sufficiently high level and the receiver able to pick it up, you have a problem.. Chains > are awful. We hate chains. Perhaps you know, but during the Apollo space shots, there were NASA ship at sea which had really high power HF transmitters. They would interfere with the radars. It turned out that the deck chains were the offenders. Whether or not there were sparks, it shows just how wide band the noise can be. Gee... What's the resonant frequency for a deck chain link? 73, Steve, K9DCI (USN, but never on a real ship untill after I got out) Article: 224793 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: FIGHT? Here is another W8JI myth bone! Date: Fri, 26 May 2006 16:40:46 -0700 Message-ID: <127f4g0kugoq117@corp.supernews.com> References: <7cd972lnqpn8ir6p97q3ajb9f87nf0bv0a@4ax.com> <1148517119.544876.272330@j33g2000cwa.googlegroups.com> <1148553494.112985.49700@j73g2000cwa.googlegroups.com> <87jb72lnlmra471luaon4p3us57g42f1o0@4ax.com> <127bjves1rp06fa@corp.supernews.com> <127d1irculdn98c@corp.supernews.com> <127eh4knvgcfo33@corp.supernews.com> Richard Clark wrote: > On Fri, 26 May 2006 11:10:28 -0700, Roy Lewallen > wrote: > >> while you claim > > Hi Roy, > > The courteous thing would be to quote me directly rather than > paraphrase me obliquely. Respond to the posting you find > objectionable. I did. I responded to the lengthy posting you reposted. Your response to that was, unfortunately, incomprehensible to me, and not apparently related to the topic in question. But here's what you've said, and with which I disagree -- that is, if I understand what you've said; I often don't. Alas, I was too often in the back room soldering things together when I should have been doing my English homework. (And see what it's done: not only poor comprehensive skills but split infinitives to boot.) ------------ On 24 May 2006 17:31:59 -0700, w8ji@akorn.net wrote: [Tom wrote:] >> >> This is part and parcel to the world of isolated and shielded >> >> circuits. The electrostatic shields are as effective as they are >> >> complete in their coverage. Their contribution is measured in mutual >> >> capacitance between the two points being isolated. > > > >I don't have that reference and so cannot see that shield, but the only > >thing the shield can do is reduce field impedance by changing the ratio > >of electric to magnetic fields. In order to take either one to zero the > >other must also be at zero. [You responded:] Hi Tom, There are too many contra-examples too sustain your point. What you are talking about is radiation, this does not account for common induction that occurs on the very short scales I've offered. 73's Richard Clark, KB7QHC ----------- And: ----------- On Wed, 24 May 2006 12:11:52 -0700, Roy Lewallen wrote: > >Richard Clark wrote: >> > > . . . >> >> Richard's applications and illustrations do not push this boundary. In >> >> fact, Ramo et. al distinctly offer the case of "electrostatic >> >> shielding" and clearly support the separation of magnetic and electric >> >> flux (fields). . . > > [I responded:] > >Can you direct me to where in the text they do so? All I've found is a > >short section (5.28) on "Electrostatic Shielding" where they explain > >that introducing a grounded conductor near two others will reduce the > >capacitive coupling between them. Obviously this will alter the local > >E/H ratio, but in no way does it allow an E or H field to exist > >independently, even locally, let alone at any distance. [To which you replied with the lengthy post which you were kind enough to post a second time. Hopefully a third time won't be necessary.] ------------ Am I mistaken, then? Were you agreeing all along that a time-varying electric or magnetic field can't exist independently and therefore there can't be completely inductive (H field) or capacitive (E field) coupling? Roy Lewallen, W7EL Article: 224794 of rec.radio.amateur.antenna Date: Fri, 26 May 2006 20:12:54 -0500 From: Tom Ring Subject: Re: One of these days. Very Soon now. References: <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net> Message-ID: <4477a796$0$1008$39cecf19@news.twtelecom.net> Radio Buff wrote: > You'll open your QST magazine to the Silent key section and Ham Radio will > be listed. > > sc GOAT Article: 224795 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Yacht Rf ground and radials Date: Fri, 26 May 2006 18:46:23 -0700 Message-ID: <127fbrgkk8uma1f@corp.supernews.com> References: <447311d0_1@news.iprimus.com.au> I put this aside until I could do a little modeling. A lot of postings have been made in the interim, but I don't see too much in the way of answers. I'll try to answer some of your questions. Will wrote: > I want to set up a hf antenna for my sailboat. > > I have read various guides from Icom etc. > > They suggest running copper foil to a Dynaplate and use sea water as > the ground. How can this work when the Dynaplate is below sea water? I don't know anything about Dynaplates, but if it's on the hull, it's very near the surface of the water. Any current it conducts will flow along the top of the water displaced by the hull. If, on the other hand, it's really under any depth of water at all, it'll be invisible to RF and might as well not be there. > Is sea water equal to copper wire radials as a RF ground system? Yes. > Does sea water make a good enough ground without radials? Yes. A foot-long wire "ground rod" below the antenna provides a nearly lossless ground connection at HF. > How can a piece of copper metal about 1 ft square equal several > radials laying on the boats deck? Radial wires are used for land based systems because of the poor conductivity of soil. Radial wires reduce the resistance of the path current takes going to and from the antenna base. Salt water is a good conductor and doesn't need -- and won't benefit from -- radial wires. > Why do i have to use copper foil when most other people suggest using > ordinary copper wire? You don't. And won't copper corrode rapidly in salt water? > Over seawater what would be the best number of radials to use > considering that maximum length i can run is 40 ft. I am planning to use > a backstay antenna with a SGC 230 Tuner. None. A simple wire down into the water is adequate. Or use a small plate very near the surface if you prefer. Roy Lewallen, W7EL Article: 224796 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: Yacht Rf ground and radials Date: Fri, 26 May 2006 18:56:49 -0700 Message-ID: <127fcf3tiuhah83@corp.supernews.com> References: <447311d0_1@news.iprimus.com.au> <23c672tptm5qalf9vhnm3tn1mtotf509hs@4ax.com> chuck wrote: > > A few additional questions along these lines for the group (with some > paraphrasing): > > 1. What is the skin depth in salt water at 14 MHz? About 2.4 inches. How would this affect > a ground plate at four feet below the surface? A ground plate at that depth would be invisible to RF. It might as well not be there. This is, of course, assuming it actually has 4 feet of water above it and not a boat's hull and air. > 2. What would the ohmic losses be over a one square foot by 33 foot path > through salt water? Let's see, salt water conductivity is about 5 S/m, which is 1.524 S/ft. So the *DC* resistance of that piece of sea water would be 1.524 * 33 / (1 * 1) ~ 50 ohms. But the RF resistivity would be much greater because only the outer few inches would carry any current. > 3. How well would the ground plate work on fresh water bodies, such as > much of the Chesapeake, the Great Lakes, and various rivers and > tributaries often used by cruisers? How would it compare with radials > over fresh water? Fresh water is quite a different story. The skin depth in *pure* fresh water at 14 MHz is 156 feet. But "fresh water" is far from pure. Unfortunately I don't have any ready data on "typical" "fresh water". So the skin depth is somewhere between 2.4 inches and 156 feet. Not much help. If the water is pretty pure, radials near the surface would be an improvement over a ground plate. > 4. Can anyone cite a published and reproducible study in which the RF > losses through salt water were measured and compared with losses through > one or more copper wire "radials" on or below deck of a typical cruising > vessel? Or is there a published theoretical analysis of this comparison? > Looking for more than the casual, anecdotal stuff. No. An NEC-4 model shows a one-foot wire to provide a nearly perfect ground in salt water. But that falls far short of your requirement. > 5. Will a four foot length of wire dropped into saltwater provide a > "good" RF "ground" and on what is the answer based? Yes, but one foot does just as well -- any current on the wire will drop to essentially zero within the first foot, so the remainder might as well not be there. This is from an NEC-4 model. > > I need enlightenment! So do we all. Roy Lewallen, W7EL Article: 224797 of rec.radio.amateur.antenna From: "Jerry Martes" References: <127e7sf1v8kjee8@corp.supernews.com> <3FKdg.56$Zb5.26@fe08.lga> Subject: Re: converting from dipole/inverted vee to beam Message-ID: Date: Sat, 27 May 2006 02:30:30 GMT "Yuri Blanarovich" wrote in message news:3FKdg.56$Zb5.26@fe08.lga... > > "Jerry Martes" wrote >> So, I'd expect the antenna's "resonance" to be defined by its >> "impedance". >> > > > Antenna resonance is defined by its element's electrical properties, > "caused" by its physical properties/dimensions. > In case of 3 el "conversion" from Inv Vee, you have to picture elements as > a tuned circuits. If they are spaced within a fractions of a wavelength, > they have mutual impedance, affecting each other. As you start adding > elements, they add capacitance to the system and lower the overall > resonant frequency and impedance. Single Dipole is around 75 ohms, 3 el. > Yagi around 30 ohms. > The more elements you add, the more sensitive the design is and requires > more prunning for optimum performance. So just slapping elements to Inv > Vee dipole will not produce optimized antenna. EZNEC, 4NEC2, MMANA are an > excellent tools to demonstrate that and to optimize the design, give you > dimensions and impedance and understanding behavior of antennas, give > current distribution in elements, plots of impedance, gain and other > parameters. > > -- > Yuri Blanarovich, K3BU, VE3BMV Hi Yuri I thought my statement that an antenna's Resonance is defined by that antenna having an impedance thats purely resistive, was an accurate statement. Is than *not* accurate?? What other "electrical properties" define an antenna's resonance?? Jerry Article: 224798 of rec.radio.amateur.antenna Message-ID: <4477BE76.6030108@fuse.net> Date: Fri, 26 May 2006 22:50:30 -0400 From: jawod Subject: Re: One of these days. Very Soon now. References: <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net> <13KdnWhtQ4VpNurZUSdV9g@ptd.net> Bob Schreibmaier wrote: > In article <5erdg.5219$921.1628@newsread4.news.pas.earthlink.net>, > email@no.spam says... > >> >>You'll open your QST magazine to the Silent key section and Ham Radio will >>be listed. > > > The Armenian judges gave this a 9.8 on the Olympic Troll-O-Meter, > but they were overruled by the umpires in instant replay, who > awarded it a 2.6. > > The Armenian judges lodged a formal protest! > > It was sufficiently trollish, of course, but way too obvious. > It was poorly written, poorly executed, and was so incredibly > lame as to lack the true drawing power of a really masterful > troll. Maybe as high as a 3.1 for the intense stupidity of the > premise, but a 9.8? Never! The Armenian judges tear their > hair out, throw their balalaikas down in dismay, and perform > the traditional Armenian Dismay Chant! They demand a recount! > > 0 2 4 6 8 10 > \ > \ > \ > \ > \ > TROLL-O-METER > Mount Ararat sucks! (A troll for the Armenian judges) Article: 224799 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: converting from dipole/inverted vee to beam Date: Fri, 26 May 2006 20:12:33 -0700 Message-ID: <127fgt1qp73oo67@corp.supernews.com> References: <127e7sf1v8kjee8@corp.supernews.com> <3FKdg.56$Zb5.26@fe08.lga> Jerry Martes wrote: > > I thought my statement that an antenna's Resonance is defined by that > antenna having an impedance thats purely resistive, was an accurate > statement. > . . . It's accurate and complete. Roy Lewallen, W7EL Article: 224800 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <127e7sf1v8kjee8@corp.supernews.com> <3FKdg.56$Zb5.26@fe08.lga> <127fgt1qp73oo67@corp.supernews.com> Subject: Re: converting from dipole/inverted vee to beam Message-ID: <5yPdg.315$Zb5.90@fe08.lga> Date: Fri, 26 May 2006 23:18:19 -0400 I will second that! Yuri "Roy Lewallen" wrote in message news:127fgt1qp73oo67@corp.supernews.com... > Jerry Martes wrote: >> >> I thought my statement that an antenna's Resonance is defined by that >> antenna having an impedance thats purely resistive, was an accurate >> statement. > > . . . > > It's accurate and complete. > > Roy Lewallen, W7EL Article: 224801 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Brainteaser References: <20319-44762304-243@storefull-3258.bay.webtv.net> <7ird729om8cgj10cl75fnmta20sq4sb0o8@4ax.com> <5g0e72h1h97vrl5k5t08t3ucsarjo5agrj@4ax.com> <94Edg.78926$F_3.75248@newssvr29.news.prodigy.net> <1148676148.656605.300060@g10g2000cwb.googlegroups.com> Message-ID: Date: Sat, 27 May 2006 03:35:37 GMT Ian White GM3SEK wrote: > It is one of the main reasons why I remain sceptical about your > theories. Where they ought to be agreeing with other analyses of the > same problem, they don't. No chance the "other analyses" could be wrong? Could you please give me an example of what you are talking about? > Also, "gobbledygook" is not a word I use... it's one of yours, I believe. I didn't say you used it, Ian, but you didn't object when it was used. -- 73, Cecil http://www.qsl.net/w5dxp Article: 224802 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1148272981_5573@sp6iad.superfeed.net> Subject: Re: Grounding a metal roof Message-ID: Date: Fri, 26 May 2006 21:12:01 -0700 "Steve N." wrote in message news:e57vbg$ehk$1@avnika.corp.mot.com... Snip > The radiation will therefore mimic that noise > also. That noisy radiation will sum with the original, desired radiation. > This, in effect, modulates the radiated signal after it leaves the > transmitter. If it is sufficiently high level and the receiver able to pick > it up, you have a problem.. Correct > Chains > > are awful. We hate chains. > Gee... What's the resonant frequency for a deck chain link? UHF or SHF, but it doesn't much matter. The training aids for the EMI Awareness course I used to teach at San Diego Naval Station (command = FTSCPAC, if you know that outfit) included a funky little plywood ship, within which were two milliwatt-level HF "transmitters" and a receiver. I/we demonstrated with two links of chain, connected back-to back to make a continuous current path, that we could generate noise by making and breaking the connection where the links touched. It was invariably a convincing demo for the students. The effect only extended out a few inches from the deck of our plywood model, but scale it up, and you are smack-dab in the real world. 73, John, KD6VKW NARTE-certified EMC Engineer (retired) USN: 1962 -1982, CTMC, EWCS (Ret.) Article: 224803 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: FIGHT? Here is another W8JI myth bone! Date: Fri, 26 May 2006 21:18:13 -0700 Message-ID: <127fko61ml12745@corp.supernews.com> References: <1148553494.112985.49700@j73g2000cwa.googlegroups.com> <87jb72lnlmra471luaon4p3us57g42f1o0@4ax.com> <127bjves1rp06fa@corp.supernews.com> <127d1irculdn98c@corp.supernews.com> <127eh4knvgcfo33@corp.supernews.com> <127f4g0kugoq117@corp.supernews.com> Wow, you got me there. I'm so used to communicating with engineers that I was actually expecting a direct and coherent response. Silly me. There was one clear and unambiguous statement in your response, though: > Fields in free space are intimately joined and inseparable. So we don't disagree after all. I see now that in your previous postings "contra-examples" really means "supporting examples", and "Ramo et. al . . . clearly support the separation of magnetic and electric flux (fields)" really means they reject it. You can really do amazing things with the English language. I'm in awe. Roy Lewallen, W7EL Richard Clark wrote: > On Fri, 26 May 2006 16:40:46 -0700, Roy Lewallen > wrote: > > Hi Roy, > >> But here's what you've said, and with which I disagree > > What appears to be the only content you disagree with: > >> There are too many contra-examples too sustain your point. What you >> are talking about is radiation, this does not account for common >> induction that occurs on the very short scales I've offered. > >> And: > >>>>>> Richard's applications and illustrations do not push this boundary. In >>>>>> fact, Ramo et. al distinctly offer the case of "electrostatic >>>>>> shielding" and clearly support the separation of magnetic and electric >>>>>> flux (fields). . . > > We never actually get to what it is that is disagreeable do we? This > is merely the window dressing for backing into an oblique translation: > >> Am I mistaken, then? > > Who can tell but you? It is, after all, your statement that you > disagree. We can only guess. > >> Were you agreeing all along that a time-varying >> electric or magnetic field can't exist independently and therefore there >> can't be completely inductive (H field) or capacitive (E field) coupling? > A 30 word speech dressed as a question is not clear writting. :-) > > Agreeing all along? > No, I am never in the habit of agreeing all along. > > A time-varying electric or magnetic field can't exist > independently? > Fields in free space are intimately joined and inseparable. > > There can't be completely inductive (H field) or capacitive (E > field) coupling? > If I am not mistaken, this is the same question again. Do you in fact > see any difference between the two that merits the boolean AND? > > Should I anticipate other philosophical questions such as > Are you agreeing all along about conductivity and Ohm's law? > Let me shock you and say NO so as to not deflate others' anticipation. > I bet they will know how to pin me down. ;-) > > 73's > Richard Clark, KB7QHC Article: 224804 of rec.radio.amateur.antenna Subject: need a date look here From: "jhdshydsguisfdbjk@zoominternet.net" Date: Sat, 27 May 2006 00:22:57 -0400 Message-ID: <1148703546_78125@sp14lax.superfeed.net> This is a multi-part message in MIME format --=_NextPart_2rfkindysadvnqw3nerasdf Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Get all the hots girls @ www.pearlymae.com --=_NextPart_2rfkindysadvnqw3nerasdf Content-Type: text/html Content-Transfer-Encoding: quoted-printable pearlymae.info
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