Subject: glowbugs V1 #140
glowbugs Monday, October 20 1997 Volume 01 : Number 140
Date: Sun, 19 Oct 1997 15:36:58 -0400 (EDT)
From: rdkeys@csemail.cropsci.ncsu.edu
Subject: Re: See's ye on da QRG 3579R545 QTR 0000-0500Z FRI-SAT
>
> At 02:03 PM 10/17/97 -0400, rdkeys@csemail.cropsci.ncsu.edu wrote:
> >Well, folks, its been a negative hump day here, today, with bureaucratic
> >bilgewash all day. Me needs a dash o' sanity fer sure..... so's mebbies
> >we sees ya on da QRG 3579R545 QTR 0000-0500Z FRI/SAT fer some fine BA/GB
> >funzies. Should be a fine cool nite on watch, this weekend.
> >
> >73/ZUT DE NA4G/Bob UP
> >
> >p.s. one kudo, par excellance, to anyone who gets their regens an' hartleys
> > up fer da weekend, and MAKES a qso!
>
> I was on 3579 last nite (Friday) for 2 hours from 2330 - 0130, called CQ
> many times with no takers. Where was everybody?
> ...Mike VE3FGU
I was there Friday night and some Saturday night. Worked a few stations.
Heard you, but when I got ready to bang on the brass monkey, you were gone.
The propagation was strange, with lots of DX coming in, so my guess is that
it was intermediate to long. Saturday, I laid a counterpoise and rehung
the antenna, so it should work a little better. I will try some Sunday night
when I get home from the gristmill, around 0300Z-0400Z or so. I had the RAL
regen on and Big Bertha at about 50 watts at idle.
Bob/NA4G
Date: Sun, 19 Oct 1997 15:54:30 -0400 (EDT)
From: rdkeys@csemail.cropsci.ncsu.edu
Subject: Re: Hartleys
> What articles did you refer to when designing your hartleys?
> I just gotta try that.
Look in the late 1928 QST's for the articles by Ross Hull and the technical
staff at ARRL. They are the best general resources. I use the following:
1. Radio News, Gernsback's help column, about June or July for the world's
simplest sending set (a Hartley using an '01A and 22.5 vdc).
2. R.P. Turner's 1925 Hartley oscillator from QST (see the Articles in the
glowbugs archives).
3. Ross Hull's 1928 series of articles on building the ``1929'' style
amateur station, in QST. (these will eventually be in the Articles
in the glowbugs archives when I get time).
4. George Grammer's 1932 article on the Hartley oscillator rig (see the
Articles in the glowbugs archives).
5. J.B. Dow's electron coupled oscillator article in the 1932 QST. (this
will be in the Articles in the glowbugs archives when I get time).
6. Duncan and Drew's 1931 Radio Telephony and Telegraphy, for a good chapter
on Amateur stations and operating (mostly paraphrases 1927/28/29 QST.
7. Mary Loomis's 1925 Radio Operating book, has lots of neat paragraphs on
early amateur stations, and simple sets.
8. George Sterling's 1929 Radio Manual, 2nd ed., which has a lot of good
generic stuff, mostly paraphrasing the 1928 QST articles.
9. Collin's Amateur Radio Handbook, about 1935, has several good chapters
on simple Hartley based rigs.
There are some other good ones, but these are the cream of the crop.
Grandma Hartley (805) is based upon 1/2/3 above. Twinnie Triode (6AS7G) is
based upon 4. Baby Hartley (6J5) is based up on 1/2.
Bob/NA4G
Date: Sun, 19 Oct 1997 20:09:07 -0400 (EDT)
From: EWoodman@aol.com
Subject: Completed Regen!
Well folks, I just completed my regen this afternoon. As with many of my
projects, what I originally intended to build is not what I ended up with. I
set out to build a two stage rig, detector and audio, using a 6SN7 dual
triode. Primary and secondary were both to be tuned and have variable
coupling. After playing around with dual tuning and some crude variable
coupling I decided that while it would be nice to have, it wouldn't really be
necessary for adequate performance and would just complicate the final
building process. So what I did was build a finished version of a receiver I
had breadboarded back a few months ago to test. It's based on a circuit in
an article from the October, 1959 issue of Popular Electronics. It uses a
6SN7 for rf amp and detector stages and a 6V6 for audio. I didn't happen to
have any spare 6V6's so mine uses a 6F6 of which I had several. A 6L6, 5881,
KT88, 6550, etc. will work just as well and all checked out ok. If you wanted
to build a compact version you could use a 6CG7 dual triode and a 6AQ5 for
audio, both miniature tubes. The original circuit used a 100K pot to control
voltage on the plate of the 6SN7 and hence also controlled regeneration. That
worked ok in my test rig but I wanted throttle cap control. I replaced the
100pf fixed cap with a 330pf variable. The 100k pot was still included and I
use it to set plate voltage. This enables you to run the rf and detector
stages at anything up to 40 volts while the audio stage runs at around 100
volts.
I use plug in coils wound on 1 1/2" plastic drain pipe on old octal tube
bases. The antenna is coupled with a 1 turn link of #14 solid wire. Tuning is
with bandset and bandspread condensers both driven with Jackson Brothers 6:1
drives. Tube sockets are breadboard octal relay sockets. The rig is built on
a 7 X 16 hardwood board with a 19" aluminum rack panel on the front.
Attachments are made by means of binding posts on a small masonite rear
panel. That's about it. The only thing left to do is finish building a wooden
cabinet to slip it into.
It works fine, regeneration control is smooth, and it has plenty of audio.
Sorry for the long-winded description but just wanted to let everyone know
that I haven't been just sitting around doing nothing!
73 Eric KA1YRV
Date: Sun, 19 Oct 1997 23:54:48 -0700 (PDT)
From: Ken Gordon <keng@uidaho.edu>
Subject: Re: See's ye on da QRG 3579R545 QTR 0000-0500Z FRI-SAT
> I was there Friday night and some Saturday night. Worked a few stations.
> Heard you, but when I got ready to bang on the brass monkey, you were gone.
> The propagation was strange, with lots of DX coming in, so my guess is that
> it was intermediate to long. Saturday, I laid a counterpoise and rehung
> the antenna, so it should work a little better. I will try some Sunday night
> when I get home from the gristmill, around 0300Z-0400Z or so. I had the RAL
> regen on and Big Bertha at about 50 watts at idle.
Hi,gang:
I was on tonight (Sunday). Started calling CQ BA/GB at 0230. About 0310, I
got an answer from W7QQQ. He was about S-2 and it took 4 tries for me to
get his call. I asked him to come back up about 0330, but when I got
there and called him, I got no answer. Probably the condx went away. I
called CQ BA/GB again about 0400 and 0430. No answer.
Was using the HW-16 at about 50 watts output.
According to my ME-165, I get 50 watts (or more if I push it) out put on
all three bands now.
Still chirpy on 40 and 15 though.
Anyone know an EASY way to cut down the current flow through the crystal
in an ECO Pierce oscillator? MUCH smaller plate-blocking/coupling cap
(the one that connects one end of the crystal to the plate) perhaps?
Someone suggested cathode bias, but that is a hassle in the
HW-16.
Even with every possible voltage to the oscillator secton regulated, it
still chirps on 40 and 15. 80 sounds pretty good though. And the VR-150s
don't even flicker with 80 meter rocks on 80.
When I use 40 meter rocks on 40 and 15, the VR tubes flicker a bit, but
when I use the VFO, making the oscillator stage act as an amp., ONE of the
VR tubes goes completely off.
Ken W7EKB
Date: Mon, 20 Oct 1997 07:18:34 -0700 (MST)
From: Jack Meadows <jackmead@getnet.com>
Subject: Re: See's ye on da QRG 3579R545 QTR 0000-0500Z FRI-SAT
Hi Ken!
Thanks for trying to pull me out of the mud! You were right at the
noise level as well. What antenna were you using? I was running
100 watts with a Allied KnightKit T-150a to an elevated vertical
antenna. The vertical is a little short for 80 meters, so I may try
to lengthen it. See you on 3579!
Best regards,
Jack W7QQQ
p.s. My receiver was the Knight R-100a. It is really good with the Q
multiplier turned on! As good or better than my ICOM rig...ha!
On
Sun,
19 Oct 1997, Ken Gordon wrote:
> > I was there Friday night and some Saturday night. Worked a few stations.
> > Heard you, but when I got ready to bang on the brass monkey, you were gone.
> > The propagation was strange, with lots of DX coming in, so my guess is that
> > it was intermediate to long. Saturday, I laid a counterpoise and rehung
> > the antenna, so it should work a little better. I will try some Sunday night
> > when I get home from the gristmill, around 0300Z-0400Z or so. I had the RAL
> > regen on and Big Bertha at about 50 watts at idle.
>
> Hi,gang:
>
> I was on tonight (Sunday). Started calling CQ BA/GB at 0230. About 0310, I
> got an answer from W7QQQ. He was about S-2 and it took 4 tries for me to
> get his call. I asked him to come back up about 0330, but when I got
> there and called him, I got no answer. Probably the condx went away. I
> called CQ BA/GB again about 0400 and 0430. No answer.
>
> Was using the HW-16 at about 50 watts output.
>
> According to my ME-165, I get 50 watts (or more if I push it) out put on
> all three bands now.
>
> Still chirpy on 40 and 15 though.
>
> Anyone know an EASY way to cut down the current flow through the crystal
> in an ECO Pierce oscillator? MUCH smaller plate-blocking/coupling cap
> (the one that connects one end of the crystal to the plate) perhaps?
> Someone suggested cathode bias, but that is a hassle in the
> HW-16.
>
> Even with every possible voltage to the oscillator secton regulated, it
> still chirps on 40 and 15. 80 sounds pretty good though. And the VR-150s
> don't even flicker with 80 meter rocks on 80.
>
> When I use 40 meter rocks on 40 and 15, the VR tubes flicker a bit, but
> when I use the VFO, making the oscillator stage act as an amp., ONE of the
> VR tubes goes completely off.
>
> Ken W7EKB
>
>
Date: Mon, 20 Oct 1997 12:12:14 -0400 (EDT)
From: rdkeys@csemail.cropsci.ncsu.edu
Subject: Re: Hartleys
> I located articles 2 & 3 yesterday in my old QST's. Ross' article is
> great, although it should be obvious to use heavy components, short leads,
> and minimal antenna coupling.
Ross Hulls articles are the epitome of the classic Hartley designs.
That is the gist of the ``1929 style'' rigs, that were mandated by the
tighter regulations in 1928. Stability and signal purity became paramount.
Ross and the crew at ARRL HQ did a yeoman effort in the middle of 1928 to
get the word out to the ham community, and provide some good basic info
for construction and wise operation of the ``1929 style'' period ham gear.
It should be mandatory reading for all Glowebuggeites. Eventually, I will
get the articles in the archives --- got them typed in but the figs still
require scanning for eps encapsulation).
> I scrounged some parts and a 7 by 15 piece of wood and am working on
> layout. Gee, I even found a 0-1A RF ammeter! One thing I noticed before
> when looking thru all the old mags, is that people were really hung up
> on the amount of antenna current - and probably had no idea what their
> actual antenna impedance was!
A 0-1 RF ammeter is ideal for most Glowbugging use, and great for most
Hartleys. I also keep a sensitive FS meter handy for tuning. My OM
used one since the spark era, and swore by it, commercially and as a
ham for 60 years. I am of the same bent ---- if the FS meter does not
indicate --- you aren't getting out very well. Peak the FS meter and
you should do fine.
I shoot for about 1-2 turns max on link couples, unless I am whole tank
coupling, where I use a normal sized tank and couple by inductive proximity.
I get very good results with just a single turn link, most of the time,
and that gives a close enough match to around 50 ohms, that one can
use a simple series coil and capacitor resonant at the QRG, to effect
a proper match, to odd quarter wave (low impedance) antennae.
On Grandma Hartley, the link is a single turn of no. 22 bell wire around
the base of the coil form, spaced about an inch from the main coil.
My coil in Grandma is just such a BC-357 tuning unit coil, but mine is
from one of the 8-10mhz tuning units and has about 12 turns of no. 10 wire.
The size of the link is not really all that critical, but rigidity is.
The size of the TANK of the Hartley or other self controlled oscillator
IS CRITICAL to good stability. For the average 10 watt or so Hartley,
no. 12 wire is THE MINIMUM. For the average 100 watt or so Hartley,
3/8 inch copper tubing or strip is THE MINIMUM. If you don't load it
up so highly, small can work, but it will be tending to heat and drift
from the circulating RF currents. The highly polished copper tubing is
not really required, but it sure looks mighty nice......
> To start with, it looks like most of my parts will be some that were
> scrounged from a couple of old BC-191 tuning units. (Wish I had had the
> 191 and the tuning units at the same time - probably will never be that
> lucky). Anyway, my circuit won't be quite as Hi-C as Ross recommends.
> The coil resonates to 3600 with about 150 - 200 pf cap. Ya think this is
> bad? The coil has pretty large wire, like maybe #12.
If the coil has more than about 20 turns, you might want to use one of
the taps on the coil to cut it down some, or short between turns with
a drop of solder (a trick I use quite often to reduce the inductance
and at the same time reduce the stray capacity --- 4 blobs around a turn
will make it effectively an RF shunt rather than a turn of a coil).
I shoot for around 12 turns on 80 meters and 20 turns on 160 meters,
and pad the oscillator tank, accordingly.
> Have you ever used any of those large brown transmitting micas from those
> tuning units? I had thought to use whatever of those I need to get to the
> upper band edge, then use a small variable for the actual freq setting.
> I am wondering if they might cause drift or wether I would be better
> off paralleling whatever variables I need to get the right capacity.
Those tub micas are the only things I use in Hartleys. Anything smaller
is probably asking for drift troubles. I use about 3 of them to pad the
tank to around 300pf, and then a 35 pf or so neutralizing capacitor as
the main tuning capacitor. All those parts can be found in the odd, unused
BC-375 tuning units that won't cover the ham bands or are otherwise not
for restoration quality use. Glass plate or fixed air capacitors can be
used, if you make/find them. Ceramic broadcasting doorknobs of the 3 inch
or larger size work well, if you can find them. Smaller doorknobs may or
may not work so well (I have had some that do and some that don't). The
tub micas usually always work well, unless they have signs of melting wax
and leakage.
Make sure the variables are firm and solidly mounted, and the bearings are
good. Bad bearings will guarantee a wobbly signal. If the bearings are
loose, and adjustable, tighten them up some and CLEAN the bearing contact
surfaces until no oxidation is present. Check variables for poor/cracked
insulating rods --- they give me fits quite often. Use steatite only if
you can, and stay away from bakelite or phenolic insulation on Hartley
tuning caps.
> I don't have any real BA looking tubes except for some 3C24's. They are
> rather neat looking with 4 pin base, grid pin out the side, and plate
> pin on top. Looks like normal operation can run as high as 2KV plate
> supply but I won't run anywhere near that.
3C24's make GREAT Hartley oscillator tubes. I use about 350-600 volts
and don't load them up too heavily. They have a nice shape, a classic
4 pin base, and glow very brightly on a breadboard. They load up fine
to about 10-15 watts input, but I would not press them much more than
that. Use biggie Fahnnestock clips or, if you can find them, the real
heat finned terminal caps.
> Could not find info on getting stuff from Glowbugs archives. Would be
> so kind as to clue me in there?
The Glowbugs archives are set up thusly:
site --- piobaire.mines.uidaho.edu (anonymous ftp, although most of the
webscrapers or browsers should work)
directory --- pub/Glowbugs (main directory with readmes etc)
pub/Glowbugs/Articles (the articles directory)
pub/Glowbugs/BAarchives (mirror of much of the BA archives)
pub/Glowbugs/BAdigests (mirror of many of the BA digests)
pub/Glowbugs/DOSutilites (where gzip is kept)
pub/Glowbugs/Dials (various printable dials)
pub/Glowbugs/GBdigests (many of the Glowbugs digests)
pub/Glowbugs/Historical (ancient radio/telegraph texts)
pub/Glowbugs/INCOMING (where new stuff can be uploaded)
pub/Glowbugs/Logs (printable generic ham logs)
pub/Glowbugs/Military (military related manuals and things)
pub/Glowbugs/Misc (misc junk [rca logo for manuals])
pub/Glowbugs/Programs (dos executables for bc221, morse)
I will add more stuff as time goes on, and folks can add things they want
to publicly archive (Glowbugs related, unencumbered or authorized materials)
by dropping it into the INCOMING directory by ftp.
I am trying to get our Illustrious Ken Gordon (the owner of the site) to
put Ghostscript up there for dos and windoz (get your own for your pet
Unix if you run that), so folks without postscript printers can print out
the postscript stuff.
Granted, most of the stuff in the Glowbugs archives is junk I have put
together, the list membership is most welcome to add to it, for the
benefit of all. Contact me, Conard, or Ken if you want to add to the
Glowbugs archives.
Remember to download things in binary format if they are gzipped. If they
are plain ascii, then you can use ascii format for downloading. All
zips and exe files require binary format downloading.
Someday....hint, hint..... other Glowbug folks with archive stuff need to
coordinate with me to make sure the cannonical site has everything.
Good Luck.....
73/ZUT DE NA4G/Bob UP
Date: Mon, 20 Oct 1997 11:07:20 -0700 (PDT)
From: Ken Gordon <keng@uidaho.edu>
Subject: Re: See's ye on da QRG 3579R545 QTR 0000-0500Z FRI-SAT
> Hi Ken!
>
Hi, Jack!
> Thanks for trying to pull me out of the mud!
And thanks to you for the same reason! :-)
> You were right at the
> noise level as well.
QSB kept you coming up to Q-5 S-2 and then dropping you back down into the
mud. Also interference from TV-set carriers, but your frequency was enough
different that it wasn't important.
> What antenna were you using?
It is an end-fed long wire with an odd shape. It runs from my basement
shack about 25 feet vertically to a small tripod tower on the roof, then
about 80 feet horizontally (west-to-east, max radiation north and south)
to a big pine tree in our back yard, then straight up the pine tree
(vertically) for about another 40-50 feet. I haven't yet figured out the
radiation pattern, but it seems to favor the south a bit.
> I was running
> 100 watts with a Allied KnightKit T-150a to an elevated vertical
> antenna.
I was running the HW-16 at about 75 watts input. At that setting,
according to my ME-165 watt meter it puts out about 50 watts.
> The vertical is a little short for 80 meters, so I may try
> to lengthen it. See you on 3579!
I'll keep trying. I have still got to find the local QRN though.
Ken W7EKB
Date: Mon, 20 Oct 1997 11:18:24 -0700 (PDT)
From: Ken Gordon <keng@uidaho.edu>
Subject: Re: Ghostscript...
I will up load this ASAP. It works beautifully in WIN DOZE 95/WORD 97.
I'll put it in INCOMING, Bob, and drop you an e-mail when I have it done
so you can put it where it should go.
Ken W7EKB
Date: Mon, 20 Oct 1997 11:23:08 -0700
From: neil <neil@aade.com>
Subject: HAMPEDIA-SNEEK PREVIEW
ANNOUNCING ALMOST ALL DIGITAL ELECTRONICS
ENCYCLOPEDIA OF AMATEUR RADIO EQUIPMENT
The encyclopedia currently contains 400
entries (100% pictures) spanning over
20 manufacturers, and 70 years.
A comprehensive index allows you to find
equipment by manufacturer and model or
you can take the 'grand tour' which takes
you page by page through the whole thing.
You can use the encyclopedia to generate a
hyperlink to a specific piece of equipment
which you can paste into usenet FOR SALE or
WTB postings. Interested parties can click
on the link to view a picture and technical
description.
The encyclopedia is currently an infant with
some poor or missing technical descriptions
but will improve with age. I have sufficient
data to add about 100 new items per month for
the next 5 or 6 months, as time permits.
The index consists of hundreds of page to page
links that I have not fully checked out on line
so if you find any bad ones, I'd appreciate an
e-mail of which don't seem to work.
CHECK IT OUT AT:
http://www.aade.com/hampedia/hampedia.htm
- --
Neil
http://www.aade.com
mailto:neil@aade.com
Almost All Digital Electronics
1412 Elm St. SE
Auburn, WA 98092
253-351-9316
Date: Mon, 20 Oct 97 13:09:17 MDT
From: "Mark Dittmar" <Mark_Dittmar@maxtor.com>
Subject: REGEN COMPLETED
My regen project for the month of October is finally complete.
Here are the particulars, for those interested parties:
The circuit is the classic two step pair of 30 triodes, and
except for component and coil details, is identical to that of kj7f's
circuit on "http://netnow.micron.net/~kj7f/glowbug/glowbug.htm." The coil
was wound on an old 26 triode tube base ( the filament was open, so I
didn't feel too bad about destroying the tube ) with 10 turns for the
secondary and 3 turns for the tickler, the coils being spaced approx. 1/8
inch apart. I used the "slot technique" described in C. Rockey's book "
Secrets of homebuit regenerative receivers ". Antenna coupling was
through a 1 turn link of #14 house wire concentric with the tuned coil,
about 3/4 inch away. Tuning was accomplished with a 100 pf bandset
capacitor, in parallel with a 15 pf bandspread capacitor, with 15 pf in
series to drop the maximum bandspread cap range to about 7.5 pf. I used a
national 5:1 velvet vernier for the bandspread dial. Grid leak was 4.7M,
and grid cap was 30 pf SM cap. Throttle condensor was a 140 pf, padded
with 100pf SM cap. RF blocking choke was a 4.7 mh. The detector was
coupled to the AF amp with a 6.4H and 1 uf LC combo. The headphones (
high impedance variety sold by AES ) were coupled to the plate of the AF
amp tube by a 2.2H and 1uf cap. I used those values of chokes only
because they were the only ones I had, seemed to work just fine. The
plate voltage was about 43 volts, and consisted of a string of 9V
"transistor" batteries wired in series.
I used a 25 ohm filament rheostat to drop the voltage from my 3V
dry cells to the 2 VDC requirement of the 30's.
The circuit was built on some spare particle board I had laying
around ( not as aesthetically pleasing as stained pine board ), and used
a piece of 1/16 inch steel plate for the front panel. All outside
connections to the circuit were made through Pfanestock clips.
Frankly, I was blown away by the performance of this simple
receiver, once I got the component values ( esp. tickler winding to tuned
coil ratio ) tweaked. There is plenty of volume, regeneration is quite
smooth and easy to control, sounds good on CW, SSB, and the SWBC
stations. I just wish that I had another of those fine national vernier
dials, to use on the bandset cap ( I believe that these are the MOST
DIFFICULT components to find in the glowbug hobby, bar none ); It would
make setting the 40 m band edges a lot easier.
If you haven't built one of these things, you should make an
effort- they are easy to build and fun to operate, and the performance
will suprise you. However, plan to do a little bit of
experimenting/tweaking of components to get the best results, and don't
inadvertently reverse the windings on your tickler coil ( guess who did
this ? ). I plan to build another one, this time with a pair of '27
triodes and maybe an AF transformer instead of the cap-choke coupling.
Now to start collecting the parts for the November HARTLEY. . .
73,
Mark Dittmar
AB0CW
Date: Mon, 20 Oct 1997 15:43:38 -0400 (EDT)
From: rdkeys@csemail.cropsci.ncsu.edu
Subject: Re: '45 Triode Hartley
> I was fortunate enough to find 3 good ( at least the filaments
> were OK and no shorts ) '45 triodes in a box of tubes that I bought at a
> recent hamfest. Naturally, I would like to use them in the Grammer
> Hartley Oscillator circuit. However, I do have a couple of questions
> about the circuit, which I was hoping that you could answer.
Great find! Now you can make the ORIGINAL Grammer Hartley set.
Neato......
> The first has to do with the value of the "grid-leak" resistor R1.
> This is a 50,000 ohm in the original circuit, which is specified to run
> at 300-400 VDC on the plate. Realistically, I will probably have only
> 250 VDC available. SInce I don't know what the intended plate current was
> for this circuit, I can't figure out how much grid bias was intended.
> How do you determine the correct value for this resistor, and insure
> oscillator startup?
Use the original value of 50K ohms to start, and then decrease until the
rated plate current is obtained under load, then run it back up until you
decrease the rated plated current by about 25% (nothing critical). The
idea is to use the rated current less some safety fudge factor. I forget
right off what the rated current is, but be conservative, and let your
45's live longer. On precious tubes, I rarely go over 50% of rated plate
current. On scarce tubes, I rarely go over 75% of rated plate current.
A better antenna makes up any difference, in practice, and receivers have
improved greatly since then, even regenerators.
> How much current do you think the original circuit was meant to draw ?
Probably around 30-50ma. Whatever you do, just remember to take it easy,
and let your tubes live a little longer. If you want biggie power, run
a 10 in the circuit. Perhaps do like Lt. Rives of the Signal School did
in his 1924 MOPA set --- parallel several! (For a classic MOPA set, see
that 1924 QST article maybe May, if memory serves me correctly, today.)
> The flashlight bulb. Any recommendations as to voltage/current
> rating ?
I use the smallest screw-in lamps that I can find. On mine, the 6SN7 set
or the 6AS7 tubes run commonly about 2.5 watts max output, so scale the
bulb to the low end. It should just glow a little. A xmastree bulb will
give some indication, but not much. A dial lamp is better. Practically
speaking, the FS meter is the best way to go, but put the lamp in for
effects, and remember that it was originally jumpered across to cut it
out of the circuit and not eat up precious ether waves!
> In lieu of the tub transmitting type caps, which I have not been
> able to find, would you recommend any other type/voltage rating ?
If I could not get any tub micas, I would first try padding using good
variables and second, make a fixed glass plate cap with probably two plates
and a 1/8 inch glass sheet (2-4 plates should work sized about 3x4-4x6 inches
or so squareish with the glass about 4x6 or 5x7 inches in size). Mount
the plates on insulating pillars for air dielectric or if glass dielectric
try a wooden or plastic tray or box or sandwich of some sort. Be creative!
On Twinnie Triode, I used tub micas, but the original Grammer design used
the large moulded micas. If you have the large moulded micas handy (i.e.,
the ones larger than the standard postage stamp sized ones), you might
try those first. If they work, use them. If the set squeels too much
from the RF strain (like drifts too much for example), find bigger caps.
Raid the broadcast folks for any surplus doorknobs, perhaps?
> I'd appreciate any advice that you could give me regarding this
> circuit. I'm preparing for November HARTLEY month, and think this
> circuit would be a great complement to my OCTOBER twin '30 regen.
Sounds like you are off to a fine start there.....
My Twinnie Triode renditions came up fine, first time, after I came to
the realization that the antenna coil was too small to work properly into
an end fed 1/4 wave antenna. I dittled a bit with the grid leaks to suit,
but other than that, that has been one of the easiest sets to get working
I have ever played with. I have sort of thought that would be a good one
to scale up for a 211 or even an 833, for fun......(:+}}....(did I say that?).
(Hint.... use larger wire in the coil and bigger parts and it works mostly
just fine with a 211.....(:+}}.....)
I feel an OT fright night or turkey-thrashing night coming on.....(:+}}.....
About the end of November or the beginning of December sounds comfy.....
Sort of depends upon how folks do in getting their sets up and functioning.
Remember, a good Hartley should be as stable as a generic junkwater sillycon
box, when properly loaded and run. Those who have heard Ol' Grandma Hartley
purring can attest to that. Twinnie Triode puts out a stable signal with
just a slight trace of a dainty lady sacheting by on the QRG. Baby Hartley
is quite stable if ye keeps her 6J5 in tempre --- bounce her around too
heartily and she will burp all over ye, she will. Jus' like any kids,
ye needs ta keep them in check with a firm but guiding hand, and they
sing the ol' CW note with the best of 'em. 'enuf said.....
73/ZUT DE NA4G/Bob UP
p.s. Even 600M has been active, lately, so the bands should get quite good
this season, even for Hartleys, Growler's, an' detectors an' one-steps.
For those with bilgewater regenerators, try 0355Z or thereabouts on
600M for WNU's evening WX run. FB CPI on a regenerator, fer sure.
End of glowbugs V1 #140
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