Subject: GLOWBUGS digest 150

From: [email-masked]
Date: Thu, 4 Apr 1996 09:06:56 -0600 (CST)

GLOWBUGS Digest 150

Topics covered in this issue include:

  1) BA/GB Net Fist Function report
	by [email-masked]
  2) DeMaw's sweep tube articles
	by Jeff Duntemann <[email-masked]>
  3) Good Listening/Marker/RX testing QRG
	by [email-masked]
  4) Re: Sweep tube amp stories wanted
	by "Barry L. Ornitz" <[email-masked]>
  5) Re: Sweep tube amp stories wanted
	by [email-masked] (David Feldman)
  6) CW
	by Jeff Duntemann <[email-masked]>
  7) Re: BA/GB Net Fist Function report
	by [email-masked]
  8) The Tube that Looks Like a Fireplug
	by Jeff Duntemann <[email-masked]>
  9) K1JJ's QRP-AM net on Sundays
	by Andy Wallace <[email-masked]>
 10) Hello there!
	by [email-masked] (Michael Herr)
 11) Re: The Tube that Looks Like a Fireplug
	by [email-masked] (michael silva)
 12) Re: Sweep tube amp stories wanted
	by [email-masked] (michael silva)
 13) Re: The Tube that Looks Like a Fireplug
	by Henry van Cleef <[email-masked]>

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

Date: Wed, 3 Apr 1996 11:13:33 -0500 (EST)
From: [email-masked]
To: [email-masked], [email-masked]
Subject: BA/GB Net Fist Function report
Message-ID: <[email-masked]>

We had a goodly bunch o' fellers aboard for the BA/GB Net Fist Function
last night.  It ran from about 0300 to just shy of 0600 when ol'
Boatanchor Bob went into the horizontal hustle mode cuz 'e cudn't a'keep
them thar peepers afloat .......zzzzzz....zzzzzzzzzzzzzzzzzzzzzzzzz........

All sorts of fine and well reputed rigs were heard last night.

  ARC-5   de K4MSG/Paul - this thing is the sweetest sounding arcusfivus
                          that I have ever heard (and nil mods thereupon).

  DX-60   de K9NO/Paul - a fine classic and clean sounding rig

  TCS     de KC5EPZ/Dennis - a fine classic military canoeanchor

  Home Brew Breadboard 35Watter   de W5TVW/Sandy - this is a very clean
                                  and crisp breadboard Glowbug rig!
                                  Kudos to the HB/Glowbuggite crowd.

  Johnson Viking Challenger       de WA2VMO/Bob - this was a real big
                                  sounding barnburner rig QSA5.

  Gonset GSB-100                  de K2LMQ/Paul - another fine classic
                                  novice rig with a big signal.

  HeathKit HW-16                  de NA4G/Bob - one o' them thar late
                                  model TVSweepusTubus novice classics

  RadioMarine ET-8019A            de NA4G/Bob - ol' Big Bertha Radiomarine
                                  burning a pair o' 813's into the late nite
                                  She is one hot momma!

So, all you lurkers, ya missed another fine watch with all sorts o' neato
an cool daddyo rigs!  Dusts ye off yer bottleburners an' joins in ye on the
fun and cammaraderie!

I challenges each and every one o' you fellers (an' ladies too) to grapples
ye up yer tin cans atop yer noggins, readys yer keys at the fore, an plys
ye a fine BA/GB watch aboard the net.  No rig is too small.  No rig is too
big.  No rig is too woebegone.  No operator/fist/QLF is unwelcome or will be
turned away.  We has a' started a fine and goodly thing 'ere mateys!

QRG 7025 QTR 0100/0200Z

QRG 3579.545 QTR 0300/0400/0500/0600Z

See's ye there, byes the bye...... fer a fine BA/GB watch!

73/ZUT DE NA4G/Bob UP

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

Date: Wed, 3 Apr 1996 09:00:22 -0700
From: Jeff Duntemann <[email-masked]>
To: [email-masked]
Subject: DeMaw's sweep tube articles
Message-ID: <[email-masked]>

I dug around in my archives last night and found two articles of interest to
sweep tubers, both by Doug DeMaw:

"Some Ground Rules for Sweep Tube Linear Amplifier Design", July 1968, p.30.
    DeMaw discusses the 6KD6 in detail and presents a grounded-grid linear
using 
    4 of the tubes.  The article is mostly an exposition of a single design
problem
    and is not especially general.

"Some Thoughts About TV Sweep Tubes", February 1980, p. 11.
    Here, he discusses several different tubes, and recaps the linear from
July '68.
    More of a design piece, and has tables of operating parameters for
several husky
    color TV sweep tubes.

Both pieces are well worth copying out for your files.  Still, with 6146s as
cheap as they are (on a par with most of the huskier sweep tubes) I see
little reason to go with the sweepers and the problems they embody.

--73--

--JD--

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

Date: Wed, 3 Apr 1996 11:32:40 -0500 (EST)
From: [email-masked]
To: [email-masked], [email-masked]
Cc: [email-masked] ()
Subject: Good Listening/Marker/RX testing QRG
Message-ID: <[email-masked]>

I was perusing the bands last weekend, after the sad demise if WLO from
the cw broadcasting biz, looking for good background music for playing
on the boatanchors and glowbug regenerators.  The following may be of
interest as some of the last remaining cw broadcasts:

STATION   BCST RUN                QRQ      QTR        QRG
-------   ---------------------   -----    --------   -----------------
WCC       daily tfc list/wx       25wpm    1650Z      6376, 8630

WCC       sunday ARA free press   25wpm    1750Z      6376, 8630

VCS       daily tfc list/wx       25wpm    1500Z      6491.5, 8440

WNU       daily tfc list/wx       30wpm    1550Z      8570 khz

WLO       daily tfc list/info     31wpm    0200Z      4343, 6416, 8514

All of the above make great background music for listening to while
playing with or testing out your BA/GB receivers.  Most are running
several KW and usually have fairly strong signals.

It seems noone does any nite cw broadcasts anymore, that I can find.

If anyone knows of any others lurking about that are good to listen to
please QSP NA4G with the info, and I will report a followup to the lists.

73/ZUT DE NA4G/Bob

.... we's a'gotta keeps de ol' bottleburner receivers percolatin' wid dat
      fine ol' CW background sweetmusicks, ye knows......(:+}}.....

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

Date: Wed, 3 Apr 1996 11:24:05 -0500 (EST)
From: "Barry L. Ornitz" <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Subject: Re: Sweep tube amp stories wanted
Message-ID: <[email-masked]>

On Wed, 3 Apr 1996, David Feldman, WB0GAZ, wrote:

> I'm looking for people's experiences with sweep tube amps, designs, etc.

Probably the best information about sweep tubes was from a "Ham Radio
Magazine" article by Bill Orr (W6SAI of Eimac) called something like "Full
Blast Operation of Sweep Tubes".  Similar information can be found in
Bill's "Radio Handbook" of the 1970's and later. 

The ONLY positive point about sweep tubes was that the tubes were cheap in
their day.  While many had high short-term plate dissipation, their
average dissipation was rather low (17 to 33 watts).  Since they were
designed for basically pulse service, this makes sense.  I had a friend
who bought a Swan 500C but was a little slow on the draw in tuning the
final.  He showed me tubes with sucked-in envelopes.  Some of the most
recent sweep tubes (6LQ6, 6MJ6) had a pyrex glass envelope making them
slightly more resistant to this. 

Some sweep tubes had their cathode connection on the top of the tube
structure giving extremely long cathode leads and high cathode inductance. 
Such tubes would never operate well over 40 meters.  Because the tubes had
a rather high power gain, they tended to be good oscillators - usually at
frequencies other than what you were trying to transmit on! 

Neutralization is a MUST. 

Getting matched tubes will be an extreme problem today.  When they were
cheap, you could buy 25 or so and get about 9 or 10 matched pairs for rigs
like the Drakes, Yaesu's, etc.  Matched trios were even more difficult and
getting four to eight matched tubes for a kilowatt was difficult even
then.  With the scarcity of these tubes today, you either have to buy
matched tubes or really spend a lot getting enough to match with.  Without
matched tubes, one tube (the one with the highest transconductance) takes
most of the load, quickly destroying itself.  The others soon follow. 

For power amplifier design today, I would avoid them like the plague.  In
fact, for SSB use you need extremely low intermodulation distortion.  This
is best achieved with a SINGLE tube.  Popular as they may be, a pair of
parallel 3-500's is no match for a single 3-1000 in linearity.  [However,
push-pull operation is the exception.  Unless you use plug-in coils,
multiband operation of a push-pull amplifier is difficult.]

If you are trying to boost a 5 or 10 watt CW homebrew transmitter to the
50 to 100 watt level, I would go with someone else's suggestion and use
6146 tubes.  These are still readily available and popular.  For a
first-time builder of a kilowatt linear, I would suggest a pair of 813's
or perhaps the 3-400/3-500 series.  Alternately 4-400's are sometimes
available used from broadcast stations, as are 833's.  These can also be
used.  Bill Orr's handbook gives some circuits as do many older ARRL
Handbooks. 

I would strongly avoid using the newer 8877/3CX1500B and other similar
tubes if you are a relative beginner to amplifier design and construction.
These tubes have a very high power gain and are useable through UHF
frequencies, thus making them very likely to burn out with parasitic
oscillations.  They are not forgiving of abuse either. 

Unless you happen to have an old commercial amplifier that used sweep 
tubes, you should avoid them unless you have a virtually unlimited supply.

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

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

Date: Wed, 3 Apr 1996 08:47:31 -0800
From: [email-masked] (David Feldman)
To: [email-masked]
Subject: Re: Sweep tube amp stories wanted
Message-ID: <[email-masked]>

Barry L. Ornitz <[email-masked]> writes:
>
>On Wed, 3 Apr 1996, David Feldman, WB0GAZ, wrote:
>
>> I'm looking for people's experiences with sweep tube amps, designs, etc.
>
>Unless you happen to have an old commercial amplifier that used sweep
>tubes, you should avoid them unless you have a virtually unlimited supply.
 
I agree for sure. I didn't explain why I was interested in the topic - I
have several existing sweeptube amps (that work fine) and got started in
ham radio in the early 70s when these were popular. My goal in the posting
was/is to get an understanding of what was going on then, particularly with
some of the crazy designs like the swan 700cx (pair 8950's), the galaxy
amp that had 10 (?) tubes, etc...
 
I appreciate the postings and e-mails so far and am saving them - they
make some really interesting reading!

I guess you would call it a nostalgia kick...
 
73 Dave WB0GAZ [email-masked]

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

Date: Wed, 3 Apr 1996 09:19:46 -0700
From: Jeff Duntemann <[email-masked]>
To: [email-masked]
Subject: CW
Message-ID: <[email-masked]>

The first CW I ever heard was WWV's ID, back in the early Sixties.  Been a
long time gone, and I miss it...

--73--

--JD--

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

Date: Wed, 3 Apr 1996 13:44:36 -0500 (EST)
From: [email-masked]
To: [email-masked] (Paul H. Bock)
Cc: [email-masked] (), [email-masked],
Subject: Re: BA/GB Net Fist Function report
Message-ID: <[email-masked]>

> Yes, K53 clatters a bit, but who cares?

Actually, the clattering of the relays is musick to a chop's ears!
It keeps ya abreast o' how yer rig be a'workin!

Back in the early days (1920's and 30's) my OM used to read the relays
on his WAR circuit rigs (BIGG ol military rigs at Ft. Sam Houston)
to keep up with the goins-on of the ops and to keep tabs on which
rig to bring up on what frequency.  All this several miles away from
where the operator was actually sitting.

Relays make good sidetone generators, when properly resonating, and
you can tell right off, if something is amiss, because the timbre of
the clackety-clack goes sour.

Note..... some relays have a much better musical sound and timbre
than others.  The GE relays used in the BC-191/BC-375 and TCM/TCU gear
make a great clicky sound.  The ones in the TBW just sound a hard clunk.
The ones in the TCS make in intermediate hard clunk, with some stacatto.
The ones in the ARC-5 are dainty harpsichord musick by comparison..(:+}}..

All ye fellers wat's thought dem thar relays was noisy.....

     ..... nay, it be sweetmusick ta de ol' 'eadbone noggin!

73/ZUT DE NA4G/Bob

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

Date: Wed, 3 Apr 1996 13:56:29 -0700
From: Jeff Duntemann <[email-masked]>
To: [email-masked]
Subject: The Tube that Looks Like a Fireplug
Message-ID: <[email-masked]>

Hi gang--

About five years ago I bought a quantity of 829Bs and 832As at the Flagstaff
hamfest here, for what amounted to about fifty cents each.  I love the way
they look to the extent that I used several of them as Christmas tree
ornaments on our company Christmas tree, which did nothing to disperse my
eccentric reputation here. 

I have a newbuild boatanchor coming together in a genuine old-old stock
Fifties wrinkle-finish cabinet: A 160, 80, and 40M CW box with an 829B final
running both sections in parallel.  The exciter is a 5763 VXO (assuming I
can get it to work well on all three bands) working right into the 829B.  My
calculations indicate I'll get sufficient drive.

But then again, I've never used the part before, at HF, VHF, or anywhere
else.  Anybody have any thoughts on the 829B at HF?  I'm being careful about
parasitics, as the part has gain well into UHF.  But most designs use the
sections in push-pull.  Do they parallel well?  Any other wisdom?  I hope to
get 80 or 90 watts input.

(I even have the little aluminum plate-cap heat sinks, which make the tube
look marvelously Deco like something out of a Flash Gordon movie.  I love it.)

And is the 832A the only transmitting tube that's wider than it is high?
(Those little Western Electronic doorknob tubes don't count!)

--73--

--JD/KG7JF
  Scottsdale, Arizona

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

Date: Wed, 3 Apr 96 17:12:54 EST
From: Andy Wallace <[email-masked]>
To: [email-masked]
Subject: K1JJ's QRP-AM net on Sundays
Message-ID: <9604032212.AA08384@kali>

Tom has gotten so swamped with mail that I won't
pass on his email address here!

Anyway, he has started a homebrew QRP-AM net on
3885 on Sunday afternoons at 4 p.m. Eastern. 
(Moved it later for the Summer.) Showing has been
very good and people have been homebrewing 
plate-modulated 6AQ5 rigs on baking tins. 

Sounds like perfect fodder for a Glowbug project
or two, if you can avoid making the only jack for
the Key. <grin>

73,
--Andy
[email-masked]

P.S. Most of the homebrewers will send you a schematic of
the rig for a SASE and some of them will be making these
diagrams available at the Rochester NH flea coming
up on 5/10-11.

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

Date: Wed, 3 Apr 1996 21:00:46 -0800
From: [email-masked] (Michael Herr)
To: [email-masked]
Subject: Hello there!
Message-ID: <v01530500ad89f327eae5@[199.120.150.96]>

Hi there, can someone give me some info on the glowbugs and how to register
72
Mike WA6ARA

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

Date: Wed, 3 Apr 1996 21:48:07 -0800
From: [email-masked] (michael silva)
To: [email-masked]
Subject: Re: The Tube that Looks Like a Fireplug
Message-ID: <[email-masked]>

Jeff D. wrote:

>Anybody have any thoughts on the 829B at HF?  I'm being careful about
>parasitics, as the part has gain well into UHF.  But most designs use 
>the sections in push-pull.  Do they parallel well?  Any other wisdom?  

This probably isn't too helpful, but in the RadLab series there are a 
number of pulse driver circuits where the two 829 sections are used in 
parallel.  Don't see why there should be any problems in your PA 
(famous last words?).

73,
Mike, KK6GM

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

Date: Wed, 3 Apr 1996 21:55:10 -0800
From: [email-masked] (michael silva)
To: [email-masked]
Subject: Re: Sweep tube amp stories wanted
Message-ID: <[email-masked]>

Barry L. Ornitz  WA4VZQ wrote: 
>...for SSB use you need extremely low intermodulation distortion.  
>This is best achieved with a SINGLE tube.  Popular as they may be, a 
>pair of parallel 3-500's is no match for a single 3-1000 in linearity. 
> [However,
>push-pull operation is the exception.  Unless you use plug-in coils,
>multiband operation of a push-pull amplifier is difficult.]

Barry, could you talk a little more about why the single tube is 
better, and why the exception for push-pull (just the even-harmonic 
cancelling, or is there more?).  Thanks for all the good info.

73,
Mike, KK6GM

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

Date: Thu, 4 Apr 1996 02:51:35 -0600 (CST)
From: Henry van Cleef <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Subject: Re: The Tube that Looks Like a Fireplug
Message-ID: <[email-masked]>

As Jeff Duntemann said
> Hi gang--
(on 829B tubes)

> But then again, I've never used the part before, at HF, VHF, or anywhere
> else.  Anybody have any thoughts on the 829B at HF?  I'm being careful about
> parasitics, as the part has gain well into UHF.  But most designs use the
> sections in push-pull.  Do they parallel well?  Any other wisdom?  I hope to
> get 80 or 90 watts input.

The 829B is simply two 807's in one bottle.  Maximum plate dissipation
is rated lower because it's harder to get the heat out of the bottle
with two of them under one roof.  However, general circuit
considerations are the same as for 807's.  

If you are going to parallel the two sections, some Q-killer resistors
between the grids and plates are in order.  
-- 
***********************************************************
Hank van Cleef  [email-masked]  [email-masked]
***********************************************************

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

End of GLOWBUGS Digest 150
**************************