Subject: GLOWBUGS digest 336

From: [email-masked]
Date: Wed, 30 Oct 1996 09:38:30 -0600 (CST)

GLOWBUGS Digest 336

Topics covered in this issue include:

  1) Re: regen report and thoughts on tube filament voltages
	by [email-masked]
  2) Re: Pinouts on type 30 tubes?
	by Bob Roehrig <[email-masked]>
  3) Re: regen report and thoughts on tube filament voltages
	by Roy Morgan <[email-masked]>
  4) Re: Online Schematics
	by "Barry L. Ornitz" <[email-masked]>
  5) Death of an idea
	by Gordon Gekko <[email-masked]>
  6) re: Electric Radio Magazine...
	by [email-masked] (Bruce Hopkins - KL7JAF)
  7) Re: Death of an idea
	by Gordon Gekko <[email-masked]>
  8) regen audio amplifier funzies
	by [email-masked]
  9) Re: Death of an idea
	by "Brian Carling" <[email-masked]>
 10) Re: Death of an idea
	by Bruce Robertson <[email-masked]>
 11) Re: Death of an idea
	by "Brian Carling" <[email-masked]>
 12) Re: regen report and ect...
	by "Robert M. Bratcher Jr." <[email-masked]>
 13) Re: Death of an idea
	by "Robert M. Bratcher Jr." <[email-masked]>
 14) Re: regen report and ect...
	by [email-masked] (Jeff Duntemann)
 15) Re: Death of an idea
	by Bob Roehrig <[email-masked]>
 16) Re: Death of an idea
	by "Robert M. Bratcher Jr." <[email-masked]>
 17) Do most people accept your fondness for tubes?
	by "Robert M. Bratcher Jr." <[email-masked]>
 18) Xformer rebuild  questions and hazardous duty
	by Guy Dragoo <[email-masked]>
 19) Re: regen report and thoughts on tube filament voltages
	by [email-masked]
 20) Curling Up With A Good Read
	by [email-masked] (John Heck)

----------------------------------------------------------------------

Date: Tue, 29 Oct 1996 11:53:14 -0500 (EST)
From: [email-masked]
To: [email-masked] (Conard Murray)
Cc: [email-masked] (), [email-masked]
Subject: Re: regen report and thoughts on tube filament voltages
Message-ID: <[email-masked]>

> My original throttle condenser was only 40 uuf. You can see why I was having
> problems! I replaced it with a 200 uuf straight-line frequency condenser. I
> also replaced my antenna coupling condenser. I was using a twisted pair of
> wires, but I put in a 5-40 uuf trimmer and got much better sensitivity with
> 10 uuf or so in the circuit. Also got a lesson in an overloaded detector
> too! Getting your first regen to work is really a feat, but once you get it
> working then you can really tinker. I can see why you like everything
> variable too. 

Now you can see the value of LOOSE coupling into the detector circuit.
It reduces overloading on strong signals.

The gimmick capacitor coupling probably was only about 3-4 pf, and may
have been a bit marginal.  The trimmer works well, in most instances for
direct coupling, and allows you the means of varying the coupling at will.

It is probably the best of all possible worlds to build a series tuned
coil-capacitor network as the primary of the coil system, and use that
sharply tuned to match the antenna (for a normal sized antenna of a 1/4
wave or so).  But very loose coupling will be required there, to keep
from overloading the detector.  The commercial receivers were done that
way.  They used variable inductive coupling between primary and secondary
circuits and that gave the advantage of additional selectivity and tuning
of the antenna circuits to resonance.

Yes, regen sets are great tinker toys!

> With the 40 uuf tuning condenser I am able to cover the whole 80M and 160M
> bands. If I ever build a regen for 40 or higher, it will surely have a much
> smaller tuning condenser! I wonder just how high I can push this old 26? 

Traditionally, bandspreading was done with a single plate tuning condenser.
Only later in the late 30's and 40's were folks using bandsetting and
bandspreading capacitors together.  Usual 20's practice was to cut plates.
With the usual coils wound for 160/80/40M, a single plate will be all that
is needed to cover the bands well.  On 160, it should cover the lower 50-100
khz.  On 80 it should cover the lower 250khz.  On 40 it should cover the
entire band.  I find that more than one plate makes the tuning too quick.
Since I use the things mostly for CW reception (although they work very
well on ssb and fair to good on am), the narrower bandspread is better for
me.  It is usual to take a small single plate variable or find a 5 or 10
plate variariable if nothing else is around and pull the plates off the rotor
shaft with careful disassembly or as a last resort with a pair of needle
nose pliers.  Be careful not to bend any remaining plates so they short.

My guess is that it should go up to 20 meters or so, reliably, although it
will be difficult to tune stably on anything above about 10 mhz.  Even
40 meters gets a tad touchy sometimes, under crowded band conditions.
Regenerators really come into their own on 80/160 meters.  If you take
care and use more modern tubes and smaller sized components, it is possible
to build a regenerator that will go up to 6 meters well.  But, using older
parts and tubes, I don't get good results at much above 30 meters, unless
some careful design and construction has been done.  The RCA RAL receiver,
which I use as the base standard for regens, does very well up through 20
meters, although the bandspreading is a bit of a problem there.  Above
20 meters it can be rather touchy to operate as a main receiver.  As a
novice, I used it on 15 meters, but it was always with some tongue-in-cheek.
It had plenty of sensitivity, and the stability was pretty good, but the
novice band was about 5 of the 1000 dial divisions.  Sneeze and you went
way out of the band and lost your QSO.

> I played around with my detector voltage this evening and didn't notice much
> difference beyond needing more feedback and less sensitivity at lower
> voltages. I was able to copy signals with 16 volts, but 24 to 36 volts works
> better. No problem copying standard stuff on a 36 inch clip lead antenna.  I
> am still using a pile of 9-volt batteries for the B supply as I got enough
> free batteries to run this rx for a couple of years. (Seems the hospital
> here changes the batteries in their stuff on a weekly basis and I have a
> friend that gets to cart off all the used batteries.) Throttle action is
> pretty smooth and the set is a joy to operate. I do still have some loose RF
> floating around on the headset wires though, but it isn't too bad. My RF
> choke is a 4-pie 2.5 mH job, so I must have a lousy layout.

Plate voltages can vary considerably.  I can get a detector to work well
on 6vdc plate, if I am careful, although the sensitivity is quite low.
On 12vdc, it works pretty well, but for practical use, requires two stages
or maybe 3 for sufficient amplification to headfone volume.  When using
two stages only, I find that 24-48 volts plate works well, with usually
around 36 volts best on triodes.  24 volts is a good comfy minimum.
Not much difference is apparent when going from 36 to 48 volts on my
sets.  On a single tuber, 48 volts is usually best, and provides some
additional gain for headfone volume.  Beyond 48 volts is not usually
needed on triodes.  For pentodes or tetrodes, the detector oscillator
circuit should remain on about 24-36 volts, but the plate circuit can
be boosted to 90 volts or so or beyond.  I get scared of regen detectors
that are NOT coupled via transformer to the tin cans at any voltages above
90 volts.  Even capacitor coupling above 90 volts is a bit dangerous, if
the capacitor should short for any reason.  Also, running more than 90
volts through tin can windings is bad on their longevity, I have found.
Several pairs of mine have gone bad when I was an unknowing novice and
put more than 90 volts through them, thinking i could get a little more
oompf out of them....wrongoo.....

I will have to look into that hospital battery supply route.  It sounds
interesting...... a never ending source of plate batteries.....(:+}}.....

For loose RF, you might try a double choke filter like so:

     ---audio line-----+-----rf choke-----+----------------audio out to next
        high side      |     2.5 mh       |                stage or tin cans
                    .01 uf              .01 uf
                       |                  |
     ---audio line-----+-----rf choke-----+----------------audio return line
        low side             2.5 mh                        or ground return

the bottom line can be grounded if the audio return is grounded and one
rf choke eliminated.  IF the line is floating into the next stage, then
use the lower one also.  All this is outside the throttle condenser and
its own rf choke if a one tube detector stage only is used.  On a two
tuber, put this in the audio output from the second tube.

If the  audio return line is grounded (as in capacitor coupled output to
tin cans or transformer coupled output to tin cans), then it may help to
put a thin sheet of aluminum behind the front panel (even tin foil will
do) grounding the sheet to the low side of the tuning capacitor and to
the dial mechanism.  That will cut down stray hand capacity tremendously.

> I think I will try it on the air tomorrow night. I will also see if I can
> lash up a 6AG7 xtal breaker built up on wood strips. This glowbugging sure
> is fun! Thanks for sharing your expertise...

Glowbugging is addictive to the ham psyche.  It presents some unusual
challenges.

I hope to get some more time to get back on the air.  I have been heavy
into chasing some grants and doing some of the occasional teaching that I
get hooked into.  Perhaps I will get time to fire up the regen and the
hartley tonight.  That would make my day!

There was some concern amongst glowbuggites that reduced filament voltages
might do harm to 70 year old tubes.  That set me to digging in the books.
I am planning some experiments using filamentary triodes in regen detector
application to measure the tube parameters in such service.  Although it
is wise to run things like '01A's at 5 volts in usual service, I am still
of the opinion that running them at reduced filament voltages and currents
in detector or low level audio service does them no harm.  The pair I have
been running for some 10 years and maybe 1000 hours at reduced voltages
are working fine, and they were well used when I got them.  In consulting
the major tube books (van der Bijl, Chaffee, Spangenberg, Gewartowski and
Watson, and Rosebury) only one suggested running thoriated tungsten filaments
at reduced temperatures would have an effect on their longevity.  Data
from Jones and Langmuir, as illustrated in Spangenberg (Fig 4.10) would be
suggestive of a reduction in filament current significantly increasing
the life of the filament, logarithmically.  The trick is to find the
reduced filament operating point that will be compatible with the required
emission levels for the plate currents used in the regenerative detector
and low level audio service.  Spangenberg (Fig 4.11) presents data that a
thoriated tungsten filament has good emission down to a temperature of
1500 degrees Kelvin, even though normal operation is at 1900 degrees Kelvin.
That is significantly lower than what 5 volts would generate on the '01A
filament.  Langmuir's data suggests that even at as low a temperature
as 1400 degrees Kelvin, the emission is only reduced to about 1 percent of
the value at 1900 degrees Kelvin.  Interestingly, data from Wien and Harms
(Handbook of Experimental Physics) indicates that the life of the thoria
on the filament surface is increased from 94,000 hours to 720,000 hours by
the simple reduction in filament temperature from 1900 degrees Kelvin to
1800 degrees Kelvin.  If we wish to conserve our 70 year old tubes, then
there is some value and wisdom in running them at reduced voltages, that
are appropriate for the type of service to which we are putting the tubes.
How much reduction in filament voltage is still open to discussion.
The plate current in detector service is approximately 1/10th that of
audio amplifier service at 135 volts.  Thus the required emission for
satisfactory service is 1/10th that for which the tube '01A is rated.
That emission can be obtained at a 1650 degree Kelvin temperature.
What I have yet to find out is at what filament voltage do I get a
1650 degree Kelvin filament temperature.  Anyone know?  All the books
I have found to date don't have a table or chart with that data shown.
Perhaps I need to go look up Jones and Langmuir's work.

> 73 and ZUT!
> de Conard ws4s
> Conard Murray  WS4S  NNN0UTN   Glowbugs Listowner  
> 217 Dyer Avenue                BA/GB net 1802.5/3579.5/7050 KHz
> Cookeville, Tn  38501          [email-masked]
> 615-526-4093                   Wise men still seek Him
>           - LICENSED ONLY TO EXTENT INDICATED ON CARTON -

The above is licensed only to the extent indicated on carton....(what carton?)

73/ZUT DE NA4G/Bob UP

------------------------------

Date: Tue, 29 Oct 1996 10:51:51 -0600 (CST)
From: Bob Roehrig <[email-masked]>
To: Art Winterbauer <[email-masked]>
Cc: Multiple recipients of list <[email-masked]>
Subject: Re: Pinouts on type 30 tubes?
Message-ID: <[email-masked]>

On Tue, 29 Oct 1996, Art Winterbauer wrote:

> Does anyone know the pinouts on a type 30 tube?  The bottom of the tube looks
> like this:
>                   4    1 
>                   O    O
> 
>                   o    o
>                   3    2
 
> The big Os show continuity with an ohm-meter, so I figured that's the directly
> heated cathode.  But of the lower pins, which is the grid and which the plate?

The most clockwise large pin is always pin 1. Count clockwise from there
as I've shown on your drawing above.

This is true for any tube base like this that doesn't have a keyway,
up thru the 7 pin jobs. usually the larger 2 pins are filament.

Pins 1 and 4 are filament, 2 is plate, and 3 is grid. Many of the older
jobs have this same pinout ('01A, 2A3, 10, 12 for example.)

        E-mail [email-masked]           73 de Bob, K9EUI
            CIS: Data / Telecom   Aurora University, Aurora, IL

------------------------------

Date: Tue, 29 Oct 1996 12:30:24 -0500
From: Roy Morgan <[email-masked]>
To: [email-masked]
Subject: Re: regen report and thoughts on tube filament voltages
Message-ID: <[email-masked]>

At 10:28 AM 10/29/96 -0600, you wrote: 

     In consulting
>the major tube books  ... running thoriated tungsten filaments
>at reduced temperatures would have an effect on their longevity.

Do we know WHICH tubes we use have thoriated tungsten filaments and which do
not!!!???  Are there some tube numbers which were produced with some batches
with and some without?

Info I have indicates the UV199 has a thoriated filament and the UX199 does
not (and different base connections, too, by the way.)
 
   ...   the life of the thoria
>on the filament surface is increased from 94,000 hours to 720,000 hours by
>the simple reduction in filament temperature from 1900 degrees Kelvin to
>1800 degrees Kelvin. 

The RCA Transmitting Tube Manual tells something about how to handle larger
tubes with thoriated tungsten filaments: in summary, run the tube at rated
filament power and watch it's output, then lower the filament power till
performance begins to degrade, then increse the filament power slightly.
This, of course is in a situation where there's a 24-hour operating engineer
in attendance and where there are enough monitoring instruments to do the job.

>What I have yet to find out is at what filament voltage do I get a
>1650 degree Kelvin filament temperature.  Anyone know?

For this you need an optical pyrometer.  Investigations await time and
opportunity.

Sooo many projects, soooo little time!

-- Roy Morgan/Building 820, Room 562/Gaithersburg  MD 20899
(National Institute of Standards and Technology,  formerly NBS)
301-975-3254 Fax: 301-948-6213  [email-masked] --

------------------------------

Date: Tue, 29 Oct 1996 12:41:49 -0500 (EST)
From: "Barry L. Ornitz" <[email-masked]>
To: Gordon Gekko <[email-masked]>, Conard Murray <[email-masked]>,
Cc: Glowbugs Mailing List <[email-masked]>,
Subject: Re: Online Schematics
Message-ID: <[email-masked]>

Sorry to rain on the parade folks, but Gordon Gekko's call on the Glowbugs
Mailing List for schematics to scan and post on an online service needs to
be rethought with intellectual property rights considered.  Gordon wrote: 

> I am ACTIVELY PROMOTING submission of printed schematics to be scanned
> and made available to everyone in this group. 

followed by:

> Include entire article if desired.  I will only scan the parts list and
> schematic itself, but I will file the rest if some one has questions. 

I am no attorney, but I can say with certainty that this violates U.S. and
International copyright law.  [I have been researching this subject to
write a FAQ on it for Boatanchors, Glowbugs, VSS and the new Usenet
rec.radio.amateur.boatanchors.]

If those original articles were copyrighted, it will be necessary to have
written permission on each before they, or even just their schematics, can
be duplicated.  If authors wish to contribute their own original designs,
this is fine.  But if you scan in a schematic from QST, you will likely
find the League will object.  Just because the article does not carry a 
copyright notice does not mean that it is in the public domain and fair 
game for scanning either.

I am sure there are those who would call me a "spoil sport" for bringing 
this issue up, but in reality I would like to keep Glowbugs prospering 
and Phil Porch away from any legal hassles that would cause him to shut 
down this list.  [Note to Conard:  Jack Hill and I have already discussed 
this briefly.  He is waiting on the draft copy of the FAQ I am writing.]

Before we have dozens of "seat of the pants lawyers" comment on this, I
suggest everyone do a web search of the various articles on copyrights and
intellectual property rights first and READ THEM.  As I said before, I am
no attorney - but I do work in R&D and, of necessity, I am very familiar
with patents, copyrights, and trademarks.  The more I studied the
copyright law, the more I realized how strict it really is. 

[The FAQ I am writing is going slowly - it may be several more weeks
before it is finished.]

As a final point to consider, look at the various compilations of
schematics published by Markus over the years.  Imagine - a book composed
of nothing but thousands of schematics and parts lists.  But Markus had to
have written permission on file from the original copyright holder for
EACH and EVERY schematic he re-published. 

		73, Barry L. Ornitz  WA4VZQ  [email-masked]

------------------------------

Date: Tue, 29 Oct 1996 10:10:33 -0800 (PST)
From: Gordon Gekko <[email-masked]>
To: [email-masked]
Subject: Death of an idea
Message-ID: <[email-masked]>

>I am no attorney, but I can say with certainty that this violates U.S. and
>International copyright law.  [I have been researching this subject to
>write a FAQ on it for Boatanchors, Glowbugs, VSS and the new Usenet
>rec.radio.amateur.boatanchors.]
>
>If those original articles were copyrighted, it will be necessary to have
>written permission on each before they, or even just their schematics, can
>be duplicated.  If authors wish to contribute their own original designs,
>this is fine.  But if you scan in a schematic from QST, you will likely
>find the League will object.  Just because the article does not carry a 
>copyright notice does not mean that it is in the public domain and fair 
>game for scanning either.
>
>I am sure there are those who would call me a "spoil sport" for bringing 
>this issue up

Ok, ya got me.  So much for that idea.  

Dave

[email-masked]

------------------------------

Date: Tue, 29 Oct 1996 09:23:51 -0800
From: [email-masked] (Bruce Hopkins - KL7JAF)
To: [email-masked]
Subject: re: Electric Radio Magazine...
Message-ID: <v01540b00ae9beac8ddad@[204.119.24.196]>

Hi Gang...

     Ditto to Jeff - KG7JF's post about the Electric Radio Magazine... Two
things things to note: 1. Your subscription allows you one 20 word add in
the magazine each month without charge...  2. If you send a request they
will send you a sample copy of the magazine...

     This is a very nicely done magazine... If you like tube gear and
vintage gear, this is a must have... From my sample issue my wife Lin -
WL7BHT was able to do a big part of her Christmas shopping... Under our
Christmas tree this year will be a WRL Globe Chief Deluxe and a
Hallicrafters S-38C, my original 1960 Novice (KN8WEF) station... Now that's
worth the price of a subscription!!!

ELECTRIC RADIO MAGAZINE
Barry Wiseman N6CSW
14643 County Road G
Cortez CO 81321-9575
970-564-9185
[email-masked]

     Take care and have fun gang... Keep-em-Glowing...

72/73/oo's  -  Bruce * KL7JAF

EMPS  QSOs=7  STATES(w/c)=1/0  DX=0
AK

Web Page:  http://www2.polarnet.com/~bhopkins

Alaska QRP Club Web Page:  http://www2.polarnet.com/~bhopkins/akqrp.html

------------------------------

Date: Tue, 29 Oct 1996 11:11:13 -0800 (PST)
From: Gordon Gekko <[email-masked]>
To: [email-masked]
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

At 12:50 PM 10/29/96 -0600, you wrote:
>At 12:11 PM 10/29/96 -0600, you wrote:
>
>Hey Dave,
>Don't give up so quick. There is a bunch of information you can archive. We
>just have to be careful what you do archive. 
>73 de Conard, ws4s
> 

I'm sure something can be worked out.  Maybe only original designs or
modifications of published ones, or something.

I just don't want to go afoul of the legal side of things.  You
can bet there are those lurking who would in fact report such
activity, and it just didn't occur to me that is is not legal to
scan and distribute copyrighted material.

I would still love to archive info - lets maybe start a forum on just
what is available, and what could be posted.

Dave
[email-masked]

------------------------------

Date: Tue, 29 Oct 1996 14:52:02 -0500 (EST)
From: [email-masked]
To: [email-masked]
Cc: [email-masked] ()
Subject: regen audio amplifier funzies
Message-ID: <[email-masked]>

Last night I had to give my usual song and dance on amplifiers to a local
ham radio class that our club teaches.  I use a simple breadboard (actually
luciteplasticboard) 1 tube amplifier as a teaching aid.  While checking it
out for the song and dance, I played around with the circuit a tad and
measured some voltages.  I found out some interesting things relating to
very low plate voltage audio service of a common 6J5 tube.  It generates
some questions that might be useful for us glowbuggites to ponder or test
out for optimizing the regenerator on low voltages......

Particulars:
-----------

Input - a 600 ohm line transformer speaker (LS-144 army speaker) driven by
        a small phone tone generator oscillator at about 440 hz via a 1 inch
        speaker.  This gave a headphone volume audio tone to feed into the
        loudspeaker used as a microphone to the amplifier.  The speaker is
        8 ohm with a built-in 600 ohm line transformer.

Output - a 1 inch cube size 5 h choke (small surplus thing stripped from a
         TRC system of Vietnam era vhf use.  Basically a 5 h output load
         rated at 0 milliamps current, used for microphone/line coupling.

Tube - common 6J5 with no biasing --- input goes to grid and ground, output
       comes from plate to ground across the 5 henry load impedance, cathode
       to ground --- about as simple as it gets - lets test the simple first.

                                6J5
                                 +----------------+------------0 audio high
                                 |                |              out
                            -----+-----           ()
    audio high in                                 () 5h choke
    0---------------------  - - - - - -           ()
                                                  |
                            ----------+           +------------0 B+
                            |         |
                                      |
                                      |
    0---------------------------------+------------------------0 GND + B-

Filament voltage - 6.3 volts ac.

Plate voltage - 12vdc from a small 7ah battery.

Input voltage across the grid to ground  - 0.1 vac max (basically a slight
                                           meter wiggle from an AC vom.

Output voltage across the 5 h load impedance - 4.0 vac.

Voltage gain - 40 (did not measure plate current, probably 1 ma or so).

Notes:  a) adding more voltage to the plate up to 24, 36, 48 did not
           increase output ac voltage appreciably.  Did not measure current.
           Need to do that.  The voltage gain came up from 0 to 12 volts
           to peak, and did not go up from there as the plate voltage
           increased.

        b) sufficient output was obtained to drive a second LS-144 as an
           output speaker to strong headphone volume, and weak but hearable
           speaker volume.  I need to check this with capacitor coupling to
           the speaker and to Hi-Z fones for comparison.  Need to test this
           for various values of coupling capacitance to maximize audio tone
           passing at about 800hz or so for tuned peaked audio output.

        c) Need to measure load currents with various output impedances and
           transformers to see which works best for headfone output typical
           for regen receiver use.

Comments:  Small plate voltages on triodes work better than expected if the
           load is properly coupled to the output device.  Impedance coupling
           of the regen audio stage looks like a pretty good option.

           Also, tube can replace transistors at low signal levels using low
           plate voltages...(:+}}.

This sounds like someting from a 40's era electronics lab, right?  Maybe fun
to do, and helpful in optimizing regenerator parameters for our fine glowbugs.

73/ZUT DE NA4G/Bob UP

------------------------------

Date: Tue, 29 Oct 1996 13:01:17 +0000
From: "Brian Carling" <[email-masked]>
To: Gordon Gekko <[email-masked]>, [email-masked], [email-masked]
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

Well guys I don't think he can go wrong with scans of hand-drawn 
schematics, ESPECIALLY since he doesn't plan to sell them or to 
distribute them outside of a small circle of non-commercial hobbyists 
who are not doing anything for profit.

I know also that the world is just not exactly sweating it over the 
commercialization of technical ideas that went by the wayside 30-50 
years ago! There is no exchange of money involved, just thoughts.
Is sharing thoughts on the design of a QRP tube exciter somehow 
taking away someone's livelihood who is in the business of mass 
marketing such radios?

If so, I WANT TO BUY ONE OF THEM! <grin!>

72.5 to all - de "G3XLQ"
73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA
[email-masked]
*** See the great ham radio resources at: 
http://www.mnsinc.com/bry/

------------------------------

Date: Tue, 29 Oct 1996 15:23:26 -0500 (EST)
From: Bruce Robertson <[email-masked]>
To: Gordon Gekko <[email-masked]>
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

On Tue, 29 Oct 1996, Gordon Gekko wrote:

> At 12:50 PM 10/29/96 -0600, you wrote:
> >At 12:11 PM 10/29/96 -0600, you wrote:
> 
> I would still love to archive info - lets maybe start a forum on just
> what is available, and what could be posted.

This seems like Yet Another Oportunity to mention the Glowbug
Bibliography:

<http://www.epas.utoronto.ca:8080/~brucerob/glowbugs/glowbugs_bib.html>

Yours,

Bruce G. Robertson  Dept. of Classics, U. of T.     

------------------------------

Date: Tue, 29 Oct 1996 14:37:47 +0000
From: "Brian Carling" <[email-masked]>
To: [email-masked], [email-masked]
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

HEY! It's a reply from AF4K!

GREAT! - First I had heard of it!
Thanks for posting - Bry, G3XLQ/W4

On 29 Oct 96, Bruce Robertson wrote:

> On Tue, 29 Oct 1996, Gordon Gekko wrote:
> 
> > At 12:50 PM 10/29/96 -0600, you wrote:
> > >At 12:11 PM 10/29/96 -0600, you wrote:
> > 
> > I would still love to archive info - lets maybe start a forum on
> > just what is available, and what could be posted.
> 
> This seems like Yet Another Oportunity to mention the Glowbug
> Bibliography:
> 
> <http://www.epas.utoronto.ca:8080/~brucerob/glowbugs/glowbugs_bib.ht
> ml>
> 
> Yours,
> 
> Bruce G. Robertson  Dept. of Classics, U. of T.     
> 
> 
73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA
[email-masked]
*** See the great ham radio resources at: 
http://www.mnsinc.com/bry/

------------------------------

Date: Tue, 29 Oct 1996 16:46:16 -0600
From: "Robert M. Bratcher Jr." <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Subject: Re: regen report and ect...
Message-ID: <[email-masked]>

All regen reading gets me to thinking I need to build another sometime soon.
Last regen I played with was in the early 70's as a teen before I got my
first ham license. There was this box of parts I was given called an
Erectronic Set. Mid 30's to 40's era version of the Rat Shack 150 in one
kits. Had several recievers and one transmitter circuit you could build. As
I remember right this thing used a battery tube or maybe 2 tubes. Set used a
wood board with many holes drilled in it. Parts were mounted on yellow
plastic bases with a pin sticking up on each end. The wires had these U
shaped connectors on them. Came with a book for building each type of set. I
put either one or two (don't remember) D cell batteries in one of the
holders and and wired together a pair of 22.5 volt batteries for the B
supply. I had fun playing around with the grid leak detector but the regen
was best! Thankfully that set had a coil for shortwave as well as the
regular AM band. Thats how I discovered shortwave listening was that old
Erectronic Set. If only I had kept it. Anybody have a fully intact one they
could pass along? Or perhaps tell me when and who made it? Right now I'm
looking through my old Radiocraft magazines and the late 30's through 50's
era ARRL handbooks I have for a really good one or two tube regen set to build!

Robert M. Bratcher Jr.
E-mail to:
[email-masked]
Record collector, 8mm, super 8, 16 and 35mm Film collector.
I like old radio's too.
Collins, Hallicrafters, National & Hammurland are my Favorites!

------------------------------

Date: Tue, 29 Oct 1996 17:31:37 -0600
From: "Robert M. Bratcher Jr." <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

At 07:59 PM 10/29/96 +0000, you wrote:
>Well guys I don't think he can go wrong with scans of hand-drawn 
>schematics, ESPECIALLY since he doesn't plan to sell them or to 
>distribute them outside of a small circle of non-commercial hobbyists 
>who are not doing anything for profit.
>
>I know also that the world is just not exactly sweating it over the 
>commercialization of technical ideas that went by the wayside 30-50 
>years ago! There is no exchange of money involved, just thoughts.
>Is sharing thoughts on the design of a QRP tube exciter somehow 
>taking away someone's livelihood who is in the business of mass 
>marketing such radios?
>
>If so, I WANT TO BUY ONE OF THEM! <grin!>
>
>72.5 to all - de "G3XLQ"
>73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA
>[email-masked]
>*** See the great ham radio resources at: 
>http://www.mnsinc.com/bry/
>

I have to agree with this one. Somewhere in copyright law is loopholes for
non profit use. Home vidio & audio tapers get away with it all the time. I
don't see any alt.binaries.pictures ect posters going to jail either. None
of the used record dealers get hassled by the record companies at collectors
shows. Yes I can see getting permission BEFORE selling a book full of other
peoples scematics but offering scanned copies that aren't sold? Thats
overreacting folks! 

Robert M. Bratcher Jr.
E-mail to:
[email-masked]
Record collector, 8mm, super 8, 16 and 35mm Film collector.
I like old radio's too.
Collins, Hallicrafters, National & Hammurland are my Favorites!

------------------------------

Date: Tue, 29 Oct 1996 16:56:26 -0700
From: [email-masked] (Jeff Duntemann)
To: [email-masked]
Cc: [email-masked]
Subject: Re: regen report and ect...
Message-ID: <[email-masked]>

>There was this box of parts I was given called an
>Erectronic Set. Mid 30's to 40's era version of the Rat Shack 150 in one
>kits. 

>Anybody have a fully intact one they
>could pass along? Or perhaps tell me when and who made it? 

I think it was an A. C. Gilbert product; they of Erector Set fame.  I'll
look into it (I have a book on them at home) and report back.

--73--

--Jeff Duntemann KG7JF
  Scottsdale, Arizona

------------------------------

Date: Tue, 29 Oct 1996 18:14:51 -0600 (CST)
From: Bob Roehrig <[email-masked]>
To: "Robert M. Bratcher Jr." <[email-masked]>
Cc: Multiple recipients of list <[email-masked]>
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

On Tue, 29 Oct 1996, Robert M. Bratcher Jr. wrote:

> I have to agree with this one. Somewhere in copyright law is loopholes for
> non profit use. Home vidio & audio tapers get away with it all the time. I
> don't see any alt.binaries.pictures ect posters going to jail either. None
> of the used record dealers get hassled by the record companies at collectors
> shows. Yes I can see getting permission BEFORE selling a book full of other
> peoples scematics but offering scanned copies that aren't sold? Thats
> overreacting folks! 

Well, technically, it is illegal to copy a video tape or to tape a phono-
graph record or CD even though it's done all the time. I think the answer
is - is it for educational purposes? The copyright laws are different
in that case.

        E-mail [email-masked]           73 de Bob, K9EUI
            CIS: Data / Telecom   Aurora University, Aurora, IL

------------------------------

Date: Wed, 30 Oct 1996 01:56:07 -0600
From: "Robert M. Bratcher Jr." <[email-masked]>
To: Bob Roehrig <[email-masked]>
Cc: [email-masked]
Subject: Re: Death of an idea
Message-ID: <[email-masked]>

At 12:14 AM 10/30/96 +0000, you wrote:
>On Tue, 29 Oct 1996, Robert M. Bratcher Jr. wrote:
>
>> I have to agree with this one. Somewhere in copyright law is loopholes for
>> non profit use. Home vidio & audio tapers get away with it all the time. I
>> don't see any alt.binaries.pictures ect posters going to jail either. None
>> of the used record dealers get hassled by the record companies at collectors
>> shows. Yes I can see getting permission BEFORE selling a book full of other
>> peoples scematics but offering scanned copies that aren't sold? Thats
>> overreacting folks! 
>
>Well, technically, it is illegal to copy a video tape or to tape a phono-
>graph record or CD even though it's done all the time. I think the answer
>is - is it for educational purposes? The copyright laws are different
>in that case.
>

If I remember right the educational part states that the video recording
must be erased after one week. Where would I check out the copyright law
anyway? I want to read the whole thing.

Robert M. Bratcher Jr.
E-mail to:
[email-masked]
Record collector, 8mm, super 8, 16 and 35mm Film collector.
I like old radio's too.
Collins, Hallicrafters, National & Hammurland are my Favorites!

------------------------------

Date: Wed, 30 Oct 1996 02:37:25 -0600
From: "Robert M. Bratcher Jr." <[email-masked]>
To: [email-masked]
Subject: Do most people accept your fondness for tubes?
Message-ID: <[email-masked]>

Has anyone not accepted your radio hobby? I've found that 99% of people
accept mine  just fine. The only one who didn't was an elderly professor of
one of the electronics classes I took in college. I had just bought a couple
dozen Radiocraft magazines at my local antique radio club the Tuesday night
before class the next morning. I brough some to class with me for a little
reading before the class started. My professor picked one up after he walked
into the room and asked

Whats this for?

I replied "Just my hobby"

His response was "Get with the times Bratcher!" then he put my 40's era
magazine down and went to the front to start class.

I've been fiddling with tubes ever since. By the way, that remark of the old
professor was in the early 1980's. Didn't bother me a bit!

Robert M. Bratcher Jr.
E-mail to:
[email-masked]
Record collector, 8mm, super 8, 16 and 35mm Film collector.
I like old radio's too.
Collins, Hallicrafters, National & Hammurland are my Favorites!

------------------------------

Date: Wed, 30 Oct 1996 08:07:57 -0600
From: Guy Dragoo <[email-masked]>
To: "'Multiple recipients of list (Boatanchors)'"
Subject: Xformer rebuild  questions and hazardous duty
Message-ID: <[email-masked]>

Howdy listmembers:
I recently acquired an mike amp for to use the parts (specifically  xformer)
for a Colpitts tx project (Thanks Alex Mendelsohn for your nicely drawn
and detailed schematic...it has been widely viewed and appreciated).
The crux of the problem is that I wanted to check out the unit so I decided
to bring'er up slowly on a variac.  Well,  I learned two things:
1.  Check the value of fuses installed in a unit before you fire it  up (had a
10 fuse instead of a 2 amp).
2.  Stay with the unit and don't go off and play with the kids while bringing
it up :-(  
Well,  I'm sure you  all see it coming...At about 90v I walked off to join the
wife & kids in frolicking in the living room, at least until I smelled the
magic smoke (my wife was not very happy about the smell I introduced to
our household).  I guess I didn't completely fry the unit cuz I'm still getting
voltage out but it crackles when power is applied.
The specific questions I have:
Is the goo that oozed out of the xformer hazardous (seems to have eaten
the paint a little) or is it just melted lacquer.
Is this xformer worth rebuilding (360v CT w/ 5v & 6.3v secondaries)?  If so,
how is this done and what is the procedure recommended for the rebuild?

Thanks and 73

Guy AC5HL

------------------------------

Date: Wed, 30 Oct 1996 10:14:00 -0500 (EST)
From: [email-masked]
To: [email-masked] (Conard Murray)
Cc: [email-masked] (), [email-masked]
Subject: Re: regen report and thoughts on tube filament voltages
Message-ID: <[email-masked]>

> How do you capacitivly (?) couple from the plate of the audio amp to the
> phones?  I can't think of a simple way to do it. 

The usual way to impedance couple is as follows:

                                           coupling cap
   >>>------audio from plate -------+-----------||---------->>> to tin cans
                                    |                           or grid bias
                                   (||)                         resistor high 
                                   (||)                         end 
                                   (||) coupling impedance
                                   (||)  
                                   (||)  
                                   (||)  
                                    |
                                    |
                                    |                 +-----<<< from tin
                                    |                 |         cans or grid
                                   to B+             to gnd     bias resistor
                                                                low end

The tube plate circuit goes through the choke to B+, but the audio goes
across the coupling cap to the next circuit (tin cans to ground or
across the grid biasing resistor of the next [first audio] stage.

The coupling cap can be anything from 0.1uf to 10uf, and you will have
to play with this value to get the best match to the following tin cans
or audio stage.  I find a value of about 1 uf to be good in most instances.

The plate coupling impedance can be anything from about 5 henries to
500 henries (actually all you need is about 10-30 in most instances).
I find a value of 10 henries to be good in most instances.

The classical National audio coupling network was a 500 henry choke and
a capacitor all in one case.  I am not exactly sure of the capacitor
value but 0.1 or 1.0 uf rings a bell.  The SW-3 and a few other of the
small 30's National style regen boxes used this sort of coupling.

This form of impedance coupling works very well with the odd junk box
chokes of a few henries value, and the odd junk box 400 or 600v leftover
audio bypass tub capacitor of a microfarad or so.  The values are entirely
non-critical.

73/ZUT DE  NA4G/Bob UP

------------------------------

Date: Wed, 30 Oct 96 10:37:16 EST
From: [email-masked] (John Heck)
To: [email-masked]
Subject: Curling Up With A Good Read
Message-ID: <[email-masked]>

Folks,
Just took delivery on a package from Lindsay Publications and now I can't wait for a
chance to curl up with one of these wonderful books. I got copies of Elmer Buchers's
"Wireless Experimenter" and his "Vacuum Tubes in Wireless Communication". Also got two
of the nice little Gernsback Educational Library reprints, NO. 1 and 2, "How To Build
4 Doerle Short Wave Sets", and "How To Make The Most Popular All Wave 1 and 2 Tube
Receivers". The Bucher books were $13.95 and $12.95 and the Gernsback books were $2.25
each. What a bargain! Lindsay is at PO Box 538, Bradley, IL 60915-0538, 815/935-5353,
and have a swell catalog. Bob Keys is right, the Buchers books seem like a must read
for glowbuggers! Ya' oughta have a catalog.
Regards,
John Heck, KC8ETS
1009 Donson Drive
Dayton, Ohio 45429
(513)865-7036(work)
[email-masked]

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End of GLOWBUGS Digest 336
**************************