[Amps] 833A 160 meter amp Phase 2 fit-up

[Vic K2VCO]

The schematic shows a swamped grid-driven circuit. I think you will need to develop about 
225 volts across that 50 ohm resistor in order to drive the tube in class B, which means 
that you'll need to hit it with about 1KW to drive it! All but 20 or 30 of those watts 
will be dissipated in the resistor.

I suggest that you use a parallel-tuned input if you want a grid-driven circuit, or use a 
cathode-driven circuit. The 833A has a mu of about 35. Usually, higher-mu tubes are used 
in cathode-driven circuits (the Eimac 3-500Z has a mu of 130). I think this is because the 
higher mu means the grid is denser and will provide better shielding, but I'm not 100% 
sure of this.

On 8/11/2010 7:08 PM, Greg Weinfurtner wrote:
> Hi all,
>           I promised that I would tell when I had made major leaps in the
> 833A, single band, 160 meter project.  Latest pictures are at
>
> http://oak.cats.ohiou.edu/~weinfurt/833/833A.html
>
>           No wiring is done as this is just the 'fit-up' to see how things
> fit.  Heavy? You bet! The two HV microwave transformers are in parallel and
> diode isolated from each other.  Grounds are common, though.  There are 4
> square inches of in each of the transformers center leg, making a total of
> 8 square inches total.  I think they will supply enough power.
>
>           Anyway, check it out if you'd like to.
> 73,
>
> Greg Weinfurtner AEE BSS
> NS8O
> 40192 State Route 689
> Meigs County
> Albany, Ohio 45710
> United States of America
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-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/