Subject: GLOWBUGS digest 37

From: [email-masked]
Date: Sun, 3 Dec 1995 20:43:23 -0600 (CST)

GLOWBUGS Digest 37

Topics covered in this issue include:

  1) Re: Coil forms and 2E24s...
	by "Tony Stalls (K4KYO)" <[email-masked]>
  2) Re: Coil forms and 2E24s...
	by [email-masked]
  3) Re: Coil forms and 2E24s...
	by Bob Roehrig <[email-masked]>
  4) Barry on the net?
	by David Stinson <[email-masked]>
  5) Re: 6146 transmitter
	by [email-masked] (Henry Silvia)
  6) Autodyne receiver project report
	by Bob Roehrig <[email-masked]>

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

Date: Sat, 2 Dec 1995 23:54:34 -0500 (EST)
From: "Tony Stalls (K4KYO)" <[email-masked]>
To: michael silva <[email-masked]>
Subject: Re: Coil forms and 2E24s...
Message-ID: <[email-masked]>

On Sat, 2 Dec 1995, michael silva wrote:

> Next, I've been thinking about plug-in coil forms, and I don't want to 
> pay AES prices for them.  I went out in the garage and got a piece of 
> 1" PVC pipe (sch 40?) and stuck it in the microwave for a minute and it 
> came out cool as the proverbial cucumber.  This would make a fine coil 
> form mounted to the base of a defunct tube (or buy the bases from AES). 
> Is there any reason this shouldn't work?  Are there other simple tests 
> I can perform on the material?

Mike and all...

I should start this off by reminding everyone that I'm one of 
those self-taught trial-and-error types who is uninformed enought to not 
be afraid to try all kinds of off-the-wall things becaus I don't know any 
better.

With the disclaimer aside, I have tried to find information on the
insulating properties of PVC, but all the ARRL publications (my usual
source) have are specifications on penetration voltages, etc.  I am told
by people who claim to know about such things that PVC is lossy and should
only be used for end insulators on antennas.  Others tell me that it's
fine for HF, but not above.  Some say it should only be used with low
power because it melts with anything over about 100 watts.  My conclusion
is that it's a excellent/good/fair/poor choice, but if it's so bad, then
why are there so many PVC antenna products on the market, typically many
of those from The Radio Works?  (Or is that stuff not PVC?) Can somebody
in the know please do a dissertation on the merits/demerits of using PVC? 

Now, getting to the coil forms, the old standby from my Novice days 
(mid-1950's) was to use plastic pill bottles.  As for sockets, why not 
make your own using a little epoxy with banana plugs and jacks?

As another choice, you can apparenty still get miniductor stock from H&R 
and make plug-in coils that way.  The Compactron transmitters we 
discussed a few days back used them.

Good luck & 73,
Tony
K4KYO
[email-masked]

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

Date: Sun, 3 Dec 1995 10:12:56 -0500 (EST)
From: [email-masked]
To: [email-masked] (Bruce Robertson)
Cc: [email-masked] (), [email-masked]
Subject: Re: Coil forms and 2E24s...
Message-ID: <[email-masked]>

> 
> Bob: regarding the quotation below, do you mean over a tube *plug*? I'm 
> trying to figure out how it would work otherwise.
> 
> 73, VE3UWL
> 
> Bruce G. Robertson  Dept. of Classics, U. of T.     
> 
> > The pvc white plastic sink extension drain tubes from the hardware
> > store slip just OVER a tube socket to make nice plug-in coil forms.

Sorry about that..... ol' foot in mouth syndrome for the ol' geezer again...

The extension tube will just fit over the common size of tube base and can
be superglued in place.  The tubes come in a size about 8 inches long and
can be cut to any required length.

Thanks for the correction.....(:+\\

> > > 73,
> > > Mike, KK6GM

73/ZUT DE NA4G/Bob

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

Date: Sun, 3 Dec 1995 10:30:07 -0600 (CST)
From: Bob Roehrig <[email-masked]>
To: michael silva <[email-masked]>
Cc: Multiple recipients of list <[email-masked]>
Subject: Re: Coil forms and 2E24s...
Message-ID: <[email-masked]>

On Sat, 2 Dec 1995, michael silva wrote:

> Next, I've been thinking about plug-in coil forms, and I don't want to 
> pay AES prices for them.  I went out in the garage and got a piece of 
> 1" PVC pipe (sch 40?) and stuck it in the microwave for a minute and it 
> came out cool as the proverbial cucumber.  This would make a fine coil 
> form mounted to the base of a defunct tube (or buy the bases from AES). 
> Is there any reason this shouldn't work?  Are there other simple tests 
> I can perform on the material?

Hi Mike - I have used PVC for a lot of coil winding and never had a
problem. It is easily available and comes in so many diameters so is
ideal. 

73 de Bob, K9EUI

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

Date: 03 Dec 95 17:11:49 EST
From: David Stinson <[email-masked]>
To: mailing list <[email-masked]>
Cc: mailing list <[email-masked]>
Subject: Barry on the net?
Message-ID: <[email-masked]>

Did I see that Barry Wiseman of Electric Radio
is now on the net?  Anyone got his email address?
TNX DE Dave AB5S/7
            [email-masked]

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

Date: Sun, 3 Dec 1995 20:20:19 -0500
From: [email-masked] (Henry Silvia)
To: [email-masked]
Subject: Re: 6146 transmitter
Message-ID: <[email-masked]>

>
>Dumb question from VE land...
>
>Who is AES ?
>
>(and if they sell Tube parts, what is their address ?)
>
>
  Antique Electronic supply.
        6221 S.maple ave.
        Tempe, AZ  85283
602-820-5411

  Hope this helps and yes by the way I, and possibly others would be
interested in some of your suppliers.

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

Date: Sun, 3 Dec 1995 19:44:56 -0600 (CST)
From: Bob Roehrig <[email-masked]>
To: glowbugs <[email-masked]>
Subject: Autodyne receiver project report
Message-ID: <[email-masked]>

Well, last weekend I built the 2 tube Autodyne, and spent this week
winding coils. One person asked me for the dope on this receiver, which
I sent out. If anyone else is interested, send me your address. 

The lineup is a 6AU6 detector (shunt fed Hartley circuit) and the
audio stage is a 6C4. Volume on both MW and SW broadcasts is more than
adequate. Volume on the ham bands is a little low at times.

I built 5 coils. The receiver has a "bandswitch" but the coils were wound
on some old Silver Marshall 5 pin plug-in forms. The bandswitch merely
changes some caps to give bandspread coverage on the ham bands. So it now
covers 400 KC to 11 MC, general coverage, and the 160, 80, 40, and 30
meter ham bands in the bandspread mode. All coils were wound with #26
enameled wire. 

Stability is excellent and the regeneration control (a pot in the screen
grid circuit) is smooth and almost noiseless. At this time, the antenna is
about 40 feet of old TV twinlead that used to feed a TV antenna but is now
just laying on the roof. It is coupled to the receiver via a 2.2pf cap.
I intend to try link coupling off the real ham antennas soon and see if that
improves sensitivity without pulling off the dial calibration. 

73 de Bob, K9EUI  ([email-masked])

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

End of GLOWBUGS Digest 37
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