[Amps] Series screen gate design help

[Ron Youvan]

Vic Rosenthal wrote:

>> But why?

>> If you're running Class C, with proper grid bias in the absence of drive, the plate&
>> screen currents will be essentially zero.

>> The ol' clamp tube scheme was used with "Linear" amplifiers.

   It was also used in transmitters, such as my Heath DX-100.  I became familiar with the clamp 
circuit (a 6AQ5) when I built a T-R switch on the Pi network and the electron noise from idling 
current was obvious in the receiver.

> If I bias the tube for class C, then the keying envelope will get very sharp. It would be
> a click generator.

   Generating key clicks depends on a bunch of things, the use of a clamp tube minimizes the amount 
of negative bias that is needed to cut off the tube when it is not in use in tetrodes and higher.

> What I'm thinking about now is having just enough fixed bias to barely cut the tube off
> (about 75V, I think) and have the rest come from the drop across a resistor in the grid
> circuit. Then maybe the bias will rise along with the drive more smoothly.
-- 
    Ron  KA4INM - The next election, I know what is going to happen, I'm going to help.