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			    GLOWBUGS Digest 343

Topics covered in this issue include:

  1) Those confusing 'L6's...
	by jeffd@coriolis.com (Jeff Duntemann)
  2) Re: 6BM8 tubes
	by lee@radioadv.com (Lee Richey)
  3) 6L6 circuit available
	by jeffd@coriolis.com (Jeff Duntemann)
  4) 36V @4.5A Power Supplies FS
	by Guy Dragoo <gdrag@proedge.com>
  5) Re: 36V @4.5A Power Supplies FS
	by jeffd@coriolis.com (Jeff Duntemann)
  6) Re: Printed Circuits that Glow
	by Doug <doug@sunrise.alpinet.net>
  7) Frequencies?
	by Doug <doug@sunrise.alpinet.net>
  8) Bringing xtals *down* in freq'y
	by Jeffrey Herman <jherman@hawaii.edu>
  9) Tube VFO emerges from its hiding place!
	by "Brian Carling" <bry@mail1.mnsinc.com>
 10) Re: Those confusing 'L6's...
	by "Brian Carling" <bry@mail1.mnsinc.com>
 11) World Radio Labs
	by "John E. Kemker, III" <kemkerj@xyzzy.net>
 12) Glowbug power!!
	by "Brian Carling" <bry@mail1.mnsinc.com>
 13) X-MAS IN NOV....N.O.S. manuals $10 ea. + ship
	by "Robert Fowle  (KC8DBC)" <hammarlund@jacksonmi.com>
 14) Re: Frequencies?
	by "Brian Carling" <bry@mail1.mnsinc.com>
 15) Re: Printed Circuits that Glow
	by "Brian Carling" <bry@mail1.mnsinc.com>
 16) Should I or shouldn't I...
	by Dave <kenwood@nwlink.com>
 17) A Visit to A.G. Tannenbaum nr. Philly
	by k7yha@juno.com (Richard H. Arland)

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

Date: Tue, 5 Nov 1996 09:55:41 -0700
From: jeffd@coriolis.com (Jeff Duntemann)
To: glowbugs@theporch.com
Subject: Those confusing 'L6's...
Message-ID: <1.5.4.32.19961105095057.00f1c610@ntserver.coriolis.com>

Hi gang--

Somebody recently discovered that 12L6's aren't 6L6's with a 12V filament.
Such a tube exists but I don't have the number here.  It's one of those 4
digit jobs if I recall.  The only two tubes that are truly compatible with
the 6L6 that I know the numbers of are the 5881 (widely used in guitar amps)
and the 1614, which is a 6L6 that can handle up to 60 watts input.  Neither
of these are cheap tubes, sigh, and both are 6.3 volt filaments.  Another
important difference lies in maximum plate voltage; the 6L6 and its true
compatibles can handle 500V, while the 50L6, 6V6, 6K6, and those are usually
limited to 350-400V.

You can create a decent small transmitter with the 12L6.  It's more or less
a 6V6 or a 50L6 with a 12V filament.  If I can find a circuit in my files
using it I'll post it; it sounds familiar enough to look around for.

--73--

--Jeff Duntemann KG7JF
  Scottsdale, Arizona


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

Date: Tue, 5 Nov 1996 09:04:21 -0500
From: lee@radioadv.com (Lee Richey)
To: <kellymed@tmxbris.mhs.oz.au>,
Subject: Re: 6BM8 tubes
Message-ID: <19961105172415410.AAA210@lee.radioadv.com>


> 
> I am also interested in using these tubes since I have a few 'pulls' from
> old TVs. Any progress reports would be appreciated here.
> 
> Murray Kelly vk4aok

Hi gang,

The 6BM8 lives!  It fired up (not literally) last nite with no problems. 
Well, 
at least not many.  My biggest, and as far as I know, my only problem is
a soft power supply.  I was expecting about 325 to 350 volts under load
but I am only getting about 260v.  Makes a difference!  When the key is
first pressed, the unloaded voltage is about 360 and output is almost 9 
watts.  40mS later the voltage has dropped to about 260 and the power 
out drops to a little over 5 watts.  Measured input at that point is around

8.5 watts.  (260v X 33mA)   My transformer is only rated at 20mA and has
a DC resistance of 500 ohms in each half of the HV winding.  'Gotta 
change that I can see.  Anyway, with 325 to 350 volts, the little 6BM8 
will easily get into the 12 watt range.

Otherwise, the little fellow worked first time.  It seems very stable, not
at
all prone to spurious output.  I use simple differential keying to turn the
osc on first and off last.  Keying waveform looks very nice except for the
power supply droop mentioned above.  I have a few more things to check
before going on the air.

Will keep you posted.

-Lee-  -WA3FIY-

http://www.radioadv.com

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

Date: Tue, 5 Nov 1996 14:44:50 -0700
From: jeffd@coriolis.com (Jeff Duntemann)
To: glowbugs@theporch.com
Subject: 6L6 circuit available
Message-ID: <1.5.4.32.19961105144005.00963b24@ntserver.coriolis.com>

Hi gang--

I cleaned up my 6AG7/6L6 transmitter circuit the other night and loaded it
up on my FTP site for general download to all interested parties.  Here's
the URL:

ftp://ftp.coriolis.com/pub/Shareware/6l635w.zip

It's a 343 KB file. Unix being what it is (gakkh) the URL is case-sensitive,
so make sure you upcase the S in Shareware.

Now, what this file contains is:

A TIF graphics image of the circuit.
A Visio V4 file of the circuit.
A Visio V3 file of the circuit.
A Visio V3 version of the Tubes stencil I created, containing several tube
patterns for use in Visio drawings.

Those who don't have Visio will be able to use the TIF but not the rest of
the files.

A few notes on the circuit: First of all, I haven't built it yet!  I'm
setting aside my 6A8 superhet project long enough to at least breadboard it
to make sure I haven't done anything *really* dumb.  It's hardly an
imaginative circuit, and there's only so many places to go wrong, but I'm
sure some of the component values at very least will change.  My
calculations of the pi net depend on a plate load impedence of 2500 ohms,
which further depends on a plate current of about 80 mils at 425 volts
running pure Class C.  Change these and you change the net values, though
there's plenty of slop in them thangs as a rule.  For good supply regulation
I recommend a power transformer rated at least 100 mils or regulation will
suffer.

But the idea is to get this design running well, touch up the diagram, and
then put the whole thing in the public domain for anybody to copy, pass
around, upload, and (lordy I hope) build.  If you build it, take note of any
changes you make and let me know.  Just be aware that this thing as shown
has NOT been shaken out.  

Once I perfect it, I will write an article around it, and provide a list of
parts vendors.  I'm deliberately trying to use of things available from AES
so those without metric tons of loose parts in the basement will have a
fighting chance.  Help me get it ticking and there will be at least one
utterly copyright-free 6L6 novice transmitter available to everybody,
anywhere, now and for all time.

And hey, if you haven't done this stuff for awhile (or maybe not ever) give
those 425 volts sufficient respect!

Those without FTP ability can send an SASE for a paper copy of the circuit:

Jeff Duntemann
The Coriolis Group, Inc.
7339 E. Acoma Drive, Suite 7
Scottsdale AZ 85260

Good luck, and give it a shot!

--73--

--Jeff Duntemann KG7JF
  Scottsdale, Arizona



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

Date: Tue, 5 Nov 1996 16:50:50 -0600
From: Guy Dragoo <gdrag@proedge.com>
To: "'Glowbugs'" <glowbugs@theporch.com>,
Subject: 36V @4.5A Power Supplies FS
Message-ID: <01BBCB39.8E9F4E80@ft233.computek.net>

These are USED computer related equipment switching power
supplies.  They have a BIG modular plug output rated at
36VDC @ 4.5 AMPS MAX with the standard computer removable
pug 110v input(also switchable to 230v).  The rating on the
unit is listed input as 360 watts 50/60 HZ,115VAC @ 5.0 A.
They are black plastic ventilated (with back screen between
the electronics and the plastic case) that separates in the
middle (held together with 4 screws).  The size is  10 x 4.5
x 3.  The heat sinks run the length of the unit (10 in) on
both sides and they appear to be every bit capable of the
rated output. They are designed to be able to stack.
I figure these would make a dandy variable or possibly using
a divider circuit suit standard voltage circuits or maybe
suit some tube circuits (especially if stacked).  I would
assume (shooting from the hip) that these units are very
stable as they were used in powering computer CPU's and
related equipment.
I figure 10 bucks a shot (with the requirement that you
forward any neat uses and circuits for use) with a $5 for
each unit covering postage to most locations.
73
Guy AC5HL
PS got a lot of 386/486 motherboards w/CPU's and MFM drives,etc,etc,etc. I won't price here as not specifically
list related but email me and I'll forward specifics.


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

Date: Tue, 5 Nov 1996 17:04:43 -0700
From: jeffd@coriolis.com (Jeff Duntemann)
To: gdrag@proedge.com
Cc: glowbugs@theporch.com
Subject: Re: 36V @4.5A Power Supplies FS
Message-ID: <1.5.4.32.19961105165957.00f1249c@ntserver.coriolis.com>

At 04:51 PM 11/5/96 -0600, Guy wrote:
>These are USED computer related equipment switching power
>supplies.  They have a BIG modular plug output rated at
>36VDC @ 4.5 AMPS MAX with the standard computer removable
>pug 110v input(also switchable to 230v).  The rating on the
>unit is listed input as 360 watts 50/60 HZ,115VAC @ 5.0 A.
>They are black plastic ventilated (with back screen between
>the electronics and the plastic case) that separates in the
>middle (held together with 4 screws).  The size is  10 x 4.5
>x 3.  The heat sinks run the length of the unit (10 in) on
>both sides and they appear to be every bit capable of the
>rated output. They are designed to be able to stack.
>I figure these would make a dandy variable or possibly using
>a divider circuit suit standard voltage circuits or maybe
>suit some tube circuits (especially if stacked).  I would
>assume (shooting from the hip) that these units are very
>stable as they were used in powering computer CPU's and
>related equipment.

Are they switchers or linear?  If they're linear they'd be very useful for
MOSFET power work.

--73--

--Jeff Duntemann KG7JF
  Scottsdale, Arizona


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

Date: Tue, 05 Nov 1996 17:16:38 -0700
From: Doug <doug@sunrise.alpinet.net>
To: glowbugs@theporch.com
Subject: Re: Printed Circuits that Glow
Message-ID: <327FD613.1A60@alpinet.net>

> Just wanted to take the pulse here: What do y'awll think of tube circuits on
> PC boards?
> 
> I'm going to breadboard my "standard" 6AG7/6L6 transmitter shortly, 
HI Jeff...as a lifelong transmitter technician, I can say that past
experience with PC board mounted power tubes hasnt been good, due to
heat damage from the tube itself.  But, that was in the days of the
older Bakelite based PCB's, and I'd really be interested to do it on
some nice, tough Glass G10 stock. 

The worst problem I've seen is trying to pull the tube from the socket
and taking the tube, socket and a chunk of the board with it...what a
mess to fix!  This happened in a commercial broadcast transmitter, in
the driver stages.

I've had really good luck with a 6AG7/pair of 1625 setup...807's work
too....crystal controlled.

Good luck, post your results...maybe even some printed inductors on
the board?

Doug Dunn, K7YD
Livingston, MT

> 
> --73--
> 
> --Jeff Duntemann KG7JF
>   Scottsdale, Arizona

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

Date: Tue, 05 Nov 1996 17:33:25 -0700
From: Doug <doug@sunrise.alpinet.net>
To: glowbugs@theporch.com
Subject: Frequencies?
Message-ID: <327FDCD5.158B@alpinet.net>

Hi Folks...I'm new to the list...was just curious which, if any freqs
have become hangouts for the Glowbug rigs?  I'm a past builder of the
type of rig that seems to be popular here...34 years ago they were the
only way I could afford to be on the air.  My best rig was a 6AG7/pair
1625 setup that ran for many years, although I've built them from 6V6,
6L6, 6J6 and 6AW8's...allways a blast.

Have fun and keep up the interesting posts.

Doug Dunn, K7YD
Livingston, MT

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

Date: 	Tue, 5 Nov 1996 14:54:57 -1000
From: Jeffrey Herman <jherman@hawaii.edu>
To: Boatanchors List <boatanchors@theporch.com>
Subject: Bringing xtals *down* in freq'y
Message-ID: <Pine.GSO.3.93.961105145145.948E-100000@uhunix2.its.Hawaii.Edu>

I've got a bunch of mil xtals marked for 7600 kc and am wondering
what the possibility is of bringing them down to 40m. Has anyone
ever had success in dropping xtals 600 kc? Am I trying to bend the
universe?

73 from very wet Hawaii,
Jeff KH2PZ


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

Date: Tue, 5 Nov 1996 13:28:32 +0000
From: "Brian Carling" <bry@mail1.mnsinc.com>
To: glowbugs@theporch.com
Subject: Tube VFO emerges from its hiding place!
Message-ID: <199611052126.QAA08240@user2.mnsinc.com>

Well, tonight is the night to finally apply voltage to the old VFO 
and see if it cranks up. I am going to bring it up very slowly and 
see if it squeaks. I will let you chaps know the results.

Bry, AF4K
********************************************************
*** 73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA *
**  E-mail to:  bry@mnsinc.com                         *
*** See the great ham radio resources at:              *
**  http://www.mnsinc.com/bry/                         *
********************************************************

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

Date: Tue, 5 Nov 1996 13:28:31 +0000
From: "Brian Carling" <bry@mail1.mnsinc.com>
To: glowbugs@theporch.com
Subject: Re: Those confusing 'L6's...
Message-ID: <199611052126.QAA08249@user2.mnsinc.com>

HEY! It's a reply from AF4K!
On  5 Nov 96, Jeff Duntemann wrote:

> Hi gang--
> 
> Somebody recently discovered that 12L6's aren't 6L6's with a 12V
> filament. Such a tube exists but I don't have the number here.  It's
> one of those 4 digit jobs if I recall.  The only two tubes that are
> truly compatible with the 6L6 that I know the numbers of are the
> 5881 (widely used in guitar amps) and the 1614, which is a 6L6 that
> can handle up to 60 watts input.  Neither of these are cheap tubes,
> sigh, and both are 6.3 volt filaments.  Another important difference
> lies in maximum plate voltage; the 6L6 and its true compatibles can
> handle 500V, while the 50L6, 6V6, 6K6, and those are usually limited
> to 350-400V.
> 
> You can create a decent small transmitter with the 12L6.  It's more
> or less a 6V6 or a 50L6 with a 12V filament.  If I can find a
> circuit in my files using it I'll post it; it sounds familiar enough
> to look around for.

Actually Jeff, the 5881 is a different tube from the 6L6.
The pinouts are the same, but the ratings are considerably lower.

A very small number of guitar amps used the 5881 compared to the huge 
number that used the 6L6.

If you troied to put 5881s in an amplifier designed for 6L6es, you 
would get weaker output and distortion in some cases.

On the other hand the 6L6GC as the "daddy of them all"  could really 
take it, and if you needed more juice you just had to go to 4 or 6 of 
the big old 6550 tubes. I remember when they were still quite 
reasonable in price about 20 years ago, and had a metallic base on 
them. Very rugged, very nice. The KT-88 was another rather high 
powered tube audio bottle that would probably have made a decent r.f. 
amp too.

********************************************************
*** 73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA *
**  E-mail to:  bry@mnsinc.com                         *
*** See the great ham radio resources at:              *
**  http://www.mnsinc.com/bry/                         *
********************************************************

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

Date: Tue, 5 Nov 1996 22:45:42 -0500 (EST)
From: "John E. Kemker, III" <kemkerj@xyzzy.net>
To: glowbugs@theporch.com
Subject: World Radio Labs
Message-ID: <Pine.LNX.3.91.961105223824.1107B-100000@www.xyzzy.net>

I just purchased a WRL Tech-Ceiver-6a (TC6-A) 6-Meter AM rig.  As per the 
previous owner's instructions, I have attached it to a variac and am 
warming it up slowly.  It is now up to 60 volts and the power supply's 
tube is getting warm.

The former owner tells me he built it in 1963 (or thereabouts), which 
makes this radio older than me!  He included the original(!) manual with 
the radio, which makes it all the more special.

Can anyone tell me more about this radio?  It appears to be meant for 
mobile as well as base operations.  I'm looking forward to receiving my 
Technician class license (passed the test Sunday) so that I can press the 
transmit switch on this baby!

73!

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

Date: Tue, 5 Nov 1996 19:18:15 +0000
From: "Brian Carling" <bry@mail1.mnsinc.com>
To: glowbugs@theporch.com
Subject: Glowbug power!!
Message-ID: <199611060316.WAA06300@user2.mnsinc.com>

Well, guys, I finally did it!
I fired up the Geloso VFO tonight!
What a messy place to try to do it on my desk in the office next to 
(actually in front of) the FT-840!
Well, I applied filament power from the Heath power supply on loan 
from Roy, and the heaters lit up!
Bravo!
So far so good.
But then I discovered that the power supply has an internal center 
tap that is grounded and the Geloso wanted one side of the heater 
power to be connected to its chassis!

Therefore I dragged out one of the BA power supplies that I recently 
inherited, and used the heater supply from that. I got it all hocked 
up with about 140V of H.T. going to the valves, and it looked good - 
the 6CL6 Osc drew about 10 mA of plate current and about 8 mA of 
screen current (using the wrong value resistor!) - but I left the 
buffer 5673 disconnected for the time being just to see if I could 
get a signal.

NOTHING on the receiver! I started troubleshooting - cleaned the band 
switch, made sure everyjthing was connected right.
"Myoh my - it's drawing plate current but no signal!" I mused to 
myself. What could possibly be wrong? AFter about an hour of testing, 
checking, measuring and thinking, I decided to stick a piece of wire 
on the output coupling cap from the first stage, and lo and behold a 
weak signal popped up on 3579 kHz Yeah! Success at last.
I connected it directly to the G5RV and put out a call - no response.

I trolled for a CQ. I called a few people, and then decided to 
activate the 5673 buffer. COnnected the output of the VFO directly to 
the coax for the G5RV and ran up a piece of wire about 6 feet long 
for receiving purposes.

I tailed a few guys as they ended QSOs and gave them a call. I was 
probably running all of 200-400 mW by this time, MISmatched into a 
long lossy feedline via some jumper cables from the BNC output jack ( 
he he!)

Oh well, at least I tried, and NOW my signal was hitting the usual 
40-45 dB over S-9 on the receiver as would be expected. I can see 
this thing has potential. Just wait until I add a bottle or two for 
some serious power level like 25 watts or so and add a PI NET output!
THEN they will hear me!

I MAY even try again on 3579 later tonight but I get sleepy around 11 
p.m. and "Boatanchor Bob" likes to burn the midnight oil before HE 
gets on 3579 at night!

It won't be long before I am holding forth with some decent set up 
here and figure out a away to key the OSC etc.  QSK would be SO nice 
too!

See you all on the air soon.

73 - Bry, AF4K / GB / QRP
********************************************************
*** 73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA *
**  E-mail to:  bry@mnsinc.com                         *
*** See the great ham radio resources at:              *
**  http://www.mnsinc.com/bry/                         *
********************************************************

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

Date: Tue, 5 Nov 1996 23:08:26 -0500
From: "Robert Fowle  (KC8DBC)" <hammarlund@jacksonmi.com>
To: boatanchors@theporch.com
Cc: glowbugs@theporch.com
Subject: X-MAS IN NOV....N.O.S. manuals $10 ea. + ship
Message-ID: <2.2.16.19961105231014.249f2ef8@fvmail.com>

ORIGINAL,  NEW OLD STOCK,   HAMMARLUND MANUALS

 2	HQ-100
15	HQ-145-A
11	HXL ONE AMP (1.5KW)
15	HX 50
26	HX-500

Need to raise cash.......the above, your choice,  $10 ea. + $3 priority mail
first manual, $1 ea additional manual .....CONT. U.S....other's extra...
they will not be this Cheap, again......
there are not many left....see quanity next to each
        
=================================================]-[->
Robert Fowle      KC8DBC
The HAMMARLUND Historian
Ph. 517-789-6721
1215 Winifred
Jackson, Mich. 49202-1946
E-mail:  hammarlund@jacksonmi.com
Web Page:  http://www.jacksonmi.com/hammarlund
                 HAMMARLUND LITERATURE WANTED
WANTED: MANUALS FOR ANY MAKE RADIO EQUIPMENT
=================================================]-[->
Boatanchors: the list: listproc@theporch.com......subscribe boatanchors
<your name>
       the news group: rec.radio.amateur.boatanchors
             news group: ham-am@Listserv@ucsd.edu....Body: add ham-am		
ME AND MY WIFE: 
	between the two of us, we know everything, what i don't know, my wife does,
and what she don't know, won't hurt her...8-)   ssssssh!


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

Date: Tue, 5 Nov 1996 21:05:01 +0000
From: "Brian Carling" <bry@mail1.mnsinc.com>
To: doug@sunrise.alpinet.net, glowbugs@theporch.com
Subject: Re: Frequencies?
Message-ID: <199611060503.AAA10878@user2.mnsinc.com>

HEY! It's a reply from AF4K!

Welcome to the list Doug! Tell us more about your past building and  
operating experiences!

See you on 3579 and 7050 kHz soon!

Bry

On  5 Nov 96, Doug wrote:

> Hi Folks...I'm new to the list...was just curious which, if any
> freqs have become hangouts for the Glowbug rigs?  I'm a past builder
> of the type of rig that seems to be popular here...34 years ago they
> were the only way I could afford to be on the air.  My best rig was
> a 6AG7/pair 1625 setup that ran for many years, although I've built
> them from 6V6, 6L6, 6J6 and 6AW8's...allways a blast.
> 
> Have fun and keep up the interesting posts.
> 
> Doug Dunn, K7YD
> Livingston, MT
> 
********************************************************
*** 73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA *
**  E-mail to:  bry@mnsinc.com                         *
*** See the great ham radio resources at:              *
**  http://www.mnsinc.com/bry/                         *
********************************************************

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

Date: Tue, 5 Nov 1996 21:05:00 +0000
From: "Brian Carling" <bry@mail1.mnsinc.com>
To: doug@sunrise.alpinet.net
Subject: Re: Printed Circuits that Glow
Message-ID: <199611060503.AAA10881@user2.mnsinc.com>

HEY! It's a reply from AF4K!

Now guys - if they had such a thing as Z.I.F. sockets for tubes that 
would be nicer! You wouldn't have to wiggle them to get  them out!

On  5 Nov 96, Doug wrote:

> > Just wanted to take the pulse here: What do y'awll think of tube
> > circuits on PC boards?
> > 
> > I'm going to breadboard my "standard" 6AG7/6L6 transmitter
> > shortly, 
> HI Jeff...as a lifelong transmitter technician, I can say that past
> experience with PC board mounted power tubes hasnt been good, due to
> heat damage from the tube itself.  But, that was in the days of the
> older Bakelite based PCB's, and I'd really be interested to do it on
> some nice, tough Glass G10 stock. 
> 
> The worst problem I've seen is trying to pull the tube from the
> socket and taking the tube, socket and a chunk of the board with
> it...what a mess to fix!  This happened in a commercial broadcast
> transmitter, in the driver stages.
> 
> I've had really good luck with a 6AG7/pair of 1625 setup...807's
> work too....crystal controlled.
> 
> Good luck, post your results...maybe even some printed inductors on
> the board?
> 
> Doug Dunn, K7YD
> Livingston, MT
> 
> > 
> > --73--
> > 
> > --Jeff Duntemann KG7JF
> >   Scottsdale, Arizona
> 
********************************************************
*** 73 from Radio AF4K / G3XLQ in Gaithersburg, MD USA *
**  E-mail to:  bry@mnsinc.com                         *
*** See the great ham radio resources at:              *
**  http://www.mnsinc.com/bry/                         *
********************************************************

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

Date: Tue, 5 Nov 1996 22:20:26 -0800 (PST)
From: Dave <kenwood@nwlink.com>
To: glowbugs@theporch.com
Subject: Should I or shouldn't I...
Message-ID: <199611060620.WAA27650@montana.nwlink.com>



Hello fellow GB'ers,

I have a dilemma here.  I want to start another small tube xmtr project,
and I have just come across an old audio amplifier chassis that would be
a terrific headstart towards that end.  

My problem is should I tear the amp apart, using the existing well-placed
sockets, power xfmr, choke, etc. or keep it as an amp?  It isn't much as
an amp (although it might make a decent modulator for about 25 watts RF).

Its a Stromberg Carlson intercom amp, open chassis, from the 50's.  The tubes
are a 6AV6, 6AU6, and a 6L6 (with a 5Y3 rectifier).  The front apron of the
chassis has a Mic, Phono, and Bass/Treble control.  The sound quality is 
pretty so-so.  NOT a McIntosh, by far!  The output is transformer coupled for
4 or 8 ohms, plus 25volts for intercom speakers.

SOOOOO....

Should I build a small transmitter on it?  Or should I use it as a
modulator, and
if so, what do you think of using the 25volt output as the modulation coil
(since
I believe it's around 1k ohms or so - a tad low)?  Or should I just keep it
for posterity?  

BTW, it works just fine as-is.

Let me know what youz guyz think.


Dave
aka Gordon Gekko
gekko@nwlink.com


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

Date: Wed, 6 Nov 1996 02:35:42 EST
From: k7yha@juno.com (Richard H. Arland)
To: boatanchors@theporch.com, Hallicrafters@juno.com, glowbugs@theporch.com
Subject: A Visit to A.G. Tannenbaum nr. Philly
Message-ID: <19961106.023553.4407.5.k7yha@juno.com>

Gang:

I had to go to Philly today for a Dr.'s appointment at the Foot and Ankle
Institute (center city...uck!). On they way I detoured to Ambler, PA, just north of Philly, right off the turnpike and Interstate 309 North to
visit the A.G. Tannenbaum facilities.

I had corresponded and spoken to Mike, K2BN, and his wife, Alice about
picking up copies of some ARRL pubs that they had. When I arrived I was
greeted by the two of them and given the grand tour. Mike has some very
interesting BAs, including TVs, console SW/BCST sets, ham gear and AM &
FM radios that he has restored. They also have a very large assortment
of used test gear for sale along with tubes, coils, caps, and good
"stuff" that every red-blooded BAer cannot live without.

The document vault is basically the entire building! Mike showed me some
of the photocopies of manuals that he sells and they were A #1quality.
Their stock of Sams PhotoFacts and CB & Autoradio repair series books is
HUGE. 

While I was there I obtained a copy of the ARRL's "How to Become A Radio
Amateur" circa 1958 and a 1956 ARRL Handbook in very good condition.
Welcome additions ot the reference library here at K7YHA. (It's a funny
thing about needing some of the older HBs and League pubs in order to
play the BA game). 

Mike and Alice gave me explicit directions on how to proceed from their
facility to my appointment in center city Philly and I was on my way to
the doctor's. In all, I enjoyed my short visit to Tannenbaum's. Mike and
Alice are nice folks and they offer quality reproductions of manuals,
PhotoFacts, and original manuals (in some cases) at resonable prices. 

And: "NO!" I don't own stock in the company. I'm just a very satisified
customer who wants to share some info on this resource open to BAers. 

Next time you need a manual or publication, talk to Alice and Mike at
A.G. Tannenbaum, P.O. Box 386, Ambler., PA 19002 (215) 540-8055 and
www.voicenet.com/~k2bn.

73 rich K7YHA

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

End of GLOWBUGS Digest 343
**************************

