Jim
Driver was just (4) 6CL6 in simplest GG form. Filament volts, Plate volts,
about 600 I recall. RFC on the un tuned input and pi net out. It was my very
first linear
The 833's were pp in and out. I had some split stator variables and Bud
coils with swinging link for the output. I especially remeber the plate
tuning cap. Gave definition to the term "bread slicer" it was that large.
Filament transformer was my first WIY (wind it yourself)
Bias supply was adjustable and somwhat regulated made from parts harvested
from an old Philco radio I recall. Don't remember the voltage I ended up
with. Just adjusted til it was right.
Plate supply of 3.5kv m or l was, of course, a pole pig and pair of 866's
foillowed by not enough L and some C. But it got by.
The whole affair was rather short lived in terms of a lifetime. Too big,
looked like a Frankenstein machine and damm near killed me when I got
careless. But is was a valuable lesson learned at the early age of 15.
Helped me make this far anyway. But is sure got me hooked on glow.
Best for the Holidays everyone
Paul K0UYA
----- Original Message -----
From: "KG8YN" <kg8yn@neo.rr.com>
To: <amps@contesting.com>
Sent: Monday, December 03, 2012 8:59 AM
Subject: Re: [Amps] Has anyone ever actually build an 833A linear?
Yea, Paul,
I'm sure it gave the CE 10 a loud voice. I'd like to see your driver
circuit.
Let me attempt to fill some blanks about your amp. Hmm... Push Pull,
amplifies both halves of the cycle, low distortion, absolutely the best
way to go! However, balanced in, balanced out. So unless you
single-ended it, I'll guess you used link coupling to a pair of air
variables connected to 600 ohm open wire. Again, absolutely the best way
to go!
And Mike,
We live in a coax world. So if you want to use a parallel design, you
should find plenty of info, use a design center curve, and halve the plate
resistance for 2 tubes. Use a pi-net calculator, and the biggest
components you can find! The hardest part is the mounting and
ventilation. One manual says, "Direct an air nozzle to the top of the
tube". Look at the commercial broadcast transmitters like Gates and
others, when 833's were popular. Make a variable bias supply. The circuit
should get you working. For grid driven parallel, the swamping resistors
are the best idea. Use 100 ohm 50W RF type on each grid. A lot of
fabrication will be required for mounting. I think the side fan is ok to
blow between 2 tubes, but the chassis bottom mounts should be open with a
lower chassis exhaust fan, and the use of top down blowers for tube
longevity. Shop for ceramic standoffs, I have some square pillars and heat
radiating caps if I can lay my hands on them. I don't know how many
833C's you have, but e-mail me if you want to sell a pair.
Jim Lewis, KG8YN
kg8yn@neo.rr.com
----- Original Message -----
From: "Paul Kraemer" <elespe@lisco.com>
To: "Mike Waters" <mikewate@gmail.com>; <amps@contesting.com>
Sent: Saturday, December 01, 2012 5:35 PM
Subject: Re: [Amps] Has anyone ever actually build an 833A linear?
One of my first linears back in about 1960 was a grid driven pp pair of
833A
I used four 6CL6 as driver for my CE 10B
When it spoke it had a loud voice.
Paul K0UYA
----- Original Message -----
From: "Mike Waters" <mikewate@gmail.com>
To: <amps@contesting.com>
Sent: Thursday, November 29, 2012 11:22 AM
Subject: [Amps] Has anyone ever actually build an 833A linear?
This article is in the 1980 ARRL Handbook, showing a grid-driven 833A in
linear service. But I have never heard of anyone actually trying it, and
I've done many Google searches.
http://www.w7ekb.com/glowbugs/projects/Universal%20Amp.pdf
I have a bunch of 833Cs here (the graphite plate version of the 833A)
and
am considering a 160m linear like it with two paralleled tubes.
73, Mike
www.w0btu.com
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
---
avast! Antivirus: Inbound message clean.
Virus Database (VPS): 121202-0, 12/02/2012
Tested on: 12/3/2012 3:16:58 AM
avast! - copyright (c) 1988-2012 AVAST Software.
http://www.avast.com
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|