[Amps] Biasing a Class C modulated final

[KA4INM]

   On 02/17/2015 03:11 PM, Paul KW7Y Baldock wrote:

> I am building a 2x813 class C final modulated by 2x813.

> The typical way to bias the class C final is with a combination of fixed
> bias applied to the control grid and bias derived from the rf drive
> through a grid resistor.

> Rather than fixed bias applied to the grid it seems that I could achieve
> the same effect by using a pseudo zener in series with the cathode,
> similar to what is used in cathode driven linears.

> Any thoughts on this approach?

   I am guessing common cathode RF amplifier, a more standard way to do 
it would be an adjustable bias supply and a clamp tube on the screen 
grid.  (6L6 or similar) look into any pre-1960 ARRL hand book.
-- 
   Ron  KA4INM - Youvan's corollary:
                 Every action results in unwanted side effects.