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Subject: glowbugs V1 #86
glowbugs            Tuesday, August 5 1997            Volume 01 : Number 086


Date: Mon, 4 Aug 1997 07:34:10 -0700 (MST)
From: Chris Trask <ctrask@primenet.com>
Subject: Re: The Flagstaff Hamfest

On Sun, 3 Aug 1997, Ken Lopez wrote:

> Jeff Duntemann wrote:
> 
> 
> > Generally, not good news.  This was the least-well-attended Flagstaff
> > hamfest of the many I've been to, both in terms of vendors and > 
> > There wasn't much vintage gear on display, and what was there seemed
> > overpriced for the condition it was in.  Keys were nearly absent, except
> > for a couple of tables catering to collectors, asking $50 for grimy
> > J-38's.  If I was a kid trying to put a cheap CW station together, I'd
> > be out of luck.
> > 
> 
> I have only been attending Ft. Tuthill for five years, but this year was
> much better than last, when the Tax men scared everyone away.  I noticed
> that this year, moreso than before, much of the "good stuff" was gone by
> noon on Friday.  I always am there at dawn when the vendors are setting
> up.  Since this process goes on most of the day, Friday is the best day
> to pick up vintage gear, parts, etc.  By Saturday afternoon, when it
> began to rain, most of the goodies were gone, and folks were packing up.
> 

	I had forfotten about the TaxMan scare of last year, but you're
right, there were considerably fewer flea market vewndours last year.
This year, however, there wer few indoor vednours, the barn on the north
side of the area being empty, as well as most of the hall on the north
side of the commercial building.

	The bargains are usually best found on Friday, and the earlier 
the better, although I was still finding one or two items right up to
the Saturday afternoon rain shower.

					  Regards,

					  Chris

     ,----------------------.       Circuit Design for the
    / If you understand it,  \            RF Impaired
   /   then it's obsolete!   /            
   \  _______,--------------'        Chris Trask / N7ZWY
  _ |/              		     Principal Engineer
 oo\                                 ATG Design Services
(__)\       _                          P.O. Box 25240
  \  \    .'  `.                  Tempe, Arizona 85285-5240
   \  \  /      \                
    \  '"        \                     Technical Editor,    
     .       (  ) \                      QRP Quarterly
      '-| )__| :.  \      	         QRP ARCI 9464
        | |  | | \  '.                
       c__; c__;  '-..'>.__      Email:  ctrask@primenet.com

                    Graphics by Loek Frederiks



Date: Mon, 4 Aug 1997 08:29:44 -0700 (MST)
From: Jeff Duntemann <jeffd@coriolis.com>
Subject: Re: The Flagstaff Hamfest

At 01:15 PM 8/3/97 -0700, Ken Lopez wrote:

>I have only been attending Ft. Tuthill for five years, but this year was
>much better than last, when the Tax men scared everyone away.  I noticed
>that this year, moreso than before, much of the "good stuff" was gone by
>noon on Friday.  I always am there at dawn when the vendors are setting
>up.  Since this process goes on most of the day, Friday is the best day
>to pick up vintage gear, parts, etc.  By Saturday afternoon, when it
>began to rain, most of the goodies were gone, and folks were packing up..
>
>So, you got the National Velvets, eh?.  Now, how did I miss those?

They were buried.  REALLY buried.  But I'm a good digger.

And next year I'm going to have to be there on Friday!  Work do get in the
way sometimes...

- --73--

- --Jeff Duntemann KG7JF
  Scottsdale, Arizona



Date: Mon, 4 Aug 1997 08:37:28 -0700 (MST)
From: Jeff Duntemann <jeffd@coriolis.com>
Subject: RF Properties of Hot Glue

Hi gang--

Awhile back at my sister in law's subdivision garage sale, I bought a hot
glue gun.  It's a great gadget, and the glue is surprisingly strong coming
out of something that looks for all the world like a crayon.  I bought it
to stick some peeling formica back onto a table edge, but it did such a
good job on that that I'm now considering it for other things.  Important
question: What are the RF properties of the polymer used in hot glue?
Could I use it to immobilize a small VHF coil on a PC board?  Tack down
toroids?  Chemistry is one of my blind spots, so if any of you chemically
inclined guys could give me a reading I'd appreciate it.

- --73--

- --Jeff Duntemann KG7JF
  Scottsdale, Arizona



Date: Mon, 04 Aug 1997 12:08:08 -0400
From: Ben Bradley <bradley@norcross.mcs.slb.com>
Subject: Re: RF Properties of Hot Glue

   I've used hot glue for non-RF projects (sealing up stereo speaker
cabinets), but not as you described. You can try the 'microwave oven'
test I've read about here and/or boatanchors, originally described to
determine the RF properties of PVC pipe:
   Put a big blob of hot glue onto a piece of paper (or something
transparent to microwaves, such as an old glass plate you're going to
throw away) and let it cool to room temperature. Put it and a cup of
water (to put a load on the microwave) into a microwave oven, and run it
on high for two or three minutes (or until something starts to happen to
the hot glue...). If at the end of that time the stuff is still at room
temperature, it's perfectly good for microwave frequencies, and probably
(though I'm not sure that transmission/absorption won't change at
different frequency ranges) good for HF and VHF too.

At 08:37 AM 8/4/97 -0700, Jeff Duntemann wrote:
>Hi gang--
>
>Awhile back at my sister in law's subdivision garage sale, I bought a hot
>glue gun.  It's a great gadget, and the glue is surprisingly strong coming
>out of something that looks for all the world like a crayon.  I bought it
>to stick some peeling formica back onto a table edge, but it did such a
>good job on that that I'm now considering it for other things.  Important
>question: What are the RF properties of the polymer used in hot glue?
>Could I use it to immobilize a small VHF coil on a PC board?  Tack down
>toroids?  Chemistry is one of my blind spots, so if any of you chemically
>inclined guys could give me a reading I'd appreciate it.
>
>--73--
>
>--Jeff Duntemann KG7JF
>  Scottsdale, Arizona
>
>
>
- -----------------------------------
       Ben Bradley, Design Engineer
       Schlumberger MCS
snail: 3155-B Northwoods Parkway
       Norcross, GA 30071-1576 USA
email: bradley@norcross.mcs.slb.com
voice: 770-368-3444 ext. 3191
fax:   770-840-8614



Date: Mon, 4 Aug 1997 13:51:55 -0500
From: ac5am@juno.com (Robert L Stolzle)
Subject: Wanted: Heathkit DX-20

Hello All,

I am looking for a DX-20. This was my first transmitter back in '58.

If anyone has one  that is in good shape and wants to part with it please
let me know.

Send e-mail direct. Include phone number also if you like and I will
reply via e-mail or phone.

73,  Bob   AC5AM



Date: Mon, 04 Aug 1997 13:01:05 -0400
From: Steve Ellington <n4lq@iglou.com>
Subject: Re: RF Properties of Hot Glue

Recently I built a TenTec qrp rig and the vfo torroid coil had to be
glued down to the
circuit board. I used hot glue and the frequency change was only a few
cycles after it
dried. Getting your finger near the coil caused a major change. Hope
this tells you
something. This was at 40mtrs not VHF though

N4LQ Steve


Jeff Duntemann wrote:

> Hi gang--
>
> Awhile back at my sister in law's subdivision garage sale, I bought a
> hot
> glue gun.  It's a great gadget, and the glue is surprisingly strong
> coming
> out of something that looks for all the world like a crayon.  I bought
> it
> to stick some peeling formica back onto a table edge, but it did such
> a
> good job on that that I'm now considering it for other things.
> Important
> question: What are the RF properties of the polymer used in hot glue?
> Could I use it to immobilize a small VHF coil on a PC board?  Tack
> down
> toroids?  Chemistry is one of my blind spots, so if any of you
> chemically
> inclined guys could give me a reading I'd appreciate it.
>
> --73--
>
> --Jeff Duntemann KG7JF
>   Scottsdale, Arizona



Date: Mon, 4 Aug 1997 17:42:36 -0700 (PDT)
From: Bob Okas <vintage@best.com>
Subject: Re: RF Properties of Hot Glue

Hi Gang,
    Glowbug builders scouring the countryside in search of Miniductor
should take note of an article in this month's QST regarding homebrewing
your own bare-wire, solenoid coils. The author used two-part epoxy, which
while taking a little longer to set than hot glue, apparently has good RF
properties at least in the HF range.

73,
Bob - W3CD
Palo Altoid, CA



Date: Tue, 5 Aug 1997 06:08:02 -0800
From: herr@ridgecrest.ca.us (Michael Herr)
Subject: Regen coupling

Ok gang, a question,
     I've been fussing with my GR-81 Heathkit regen, doing some various
mods. The heathkit has an option for either magnetic coupling of the
antenna or capacitive. I have fussed with the coupling cap, going from a
12pf mica to a 3 turn gimmick (about 3 pf) with good results. In all this I
have found that sometimes the magnetic coupling works better than the
capacitive, and other conditions the capcitive does, all with the same
antenna. The capacitve coupling certainally does better as far as the
swinging antenna syndrom is concerned. So the question is, which do you all
feel is better and that I should pursue more? My present thinking is the
capacitive, perhaps with a variable so I can tweak it. What you all think?
vy 73
Mike WA6ARA



Date: Tue, 05 Aug 1997 10:11:12 -0400
From: Roy Morgan <morgan@speckle.ncsl.nist.gov>
Subject: D-104, is crystal or ceramic better?

Globuggers and Anchorites,

My D-104 seems to be dead, and I plan to order a new element for it.

Any preferences between the crystal and ceremic elements?


For Astatic information (the distributor):

http://www.ctiaudio.com./

To order products (one dealer, CB stuff mostly):

http://www.tigerpaw.com/thomasdt/index.html-ssi


Keep em Glowing!
Roy, K1LKY since 1959

- -- Roy Morgan/Building 820, Room 562/Gaithersburg  MD 20899
(National Institute of Standards and Technology,  formerly NBS)
301-975-3254 Fax: 301-948-6213  morgan@speckle.ncsl.nist.gov --



Date: Tue, 5 Aug 1997 10:37:59 +0000 (GMT)
From: Jim Glover <psykey@okcforum.org>
Subject: HW-101 ...weak tubes?

Hi, everyone!

I'm looking forward to enjoying the glowbugs list.

Weekend before last, I bought a Heathkit HW-101 at the hamfest
here in Oklahoma City, for $100.  The price was low, because
it's no longer putting out full power.  The guy who sold it to
me believed that the finals or driver must be getting weak.
Since getting to know it, I've decided that the driver and/or
finals are not the only weak tubes.  There are apparently one
or more weak tubes associated with receiving.

The reduced power doesn't concern me.  My wattmeter tops out at
100 watts, and I don't have any trouble pushing the CW output
power beyond that.  That should be enough power.  However, the
receiver seems to be weak, and that's more of a problem.  Here
are some of the symptoms:

- --The strongest signals on the band show about S6.  Only the
  remarkably strong signals move the S-meter at all.

- --Backing off of the RF gain pushes the S-meter only up to about
  S6, where it stops advancing as the RF gain is reduced further.

- --Every few minutes, the receiver output begins to fade away,
  dropping to complete silence within a few seconds.  Changing
  the mode switch to another mode and back will usually restore
  normal operation (normal for this receiver, anyway).

These symptoms lead me to believe that one or more tubes 
associated with the receiver are weak.  Do any of you know the
HW-101 and its internal workings intimately enough to speculate
about which tubes I should suspect?  How should I proceed with
troubleshooting this?  Should I attempt to guess which tube(s)
may be getting weak, and just swap 'em out and try it again,
to see if I guessed right?  Is any sort of re-alignment needed
after replacing tubes?

Also... in general, how goes the availability of tubes for ham
gear in general, and the HW-101 specifically?  Where should I
look for tubes for the HW-101?

Thanks in advance for any pointers you can give me!

- --Jim  WB5UDE



End of glowbugs V1 #86
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