[Amps] Has anyone ever actually build an 833A linear?

[Paul Kraemer]

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 at neo.rr.com>
To: <amps at 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 at neo.rr.com
>
>
> ----- Original Message ----- 
> From: "Paul Kraemer" <elespe at lisco.com>
> To: "Mike Waters" <mikewate at gmail.com>; <amps at 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 at gmail.com>
>> To: <amps at 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 at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
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