[Amps] Need for input tuning circuit

[Vic Rosenthal]

DF3KV wrote:


> How was full class-C maintained on the opposite cycle, when  no grid
> current flows?
> For full class-C the 813 has to be biased with -155V at 2250V EHT

There needs to be a capacitor across the grid resistor that is charged during 
the period that grid current is flowing.  If you have a parallel tuned input 
circuit from grid to ground, the blocking capacitor that keeps the bias from 
being shorted out by the coil performs this function.  Or you can have an RF 
choke connected to the grid in series with the grid resistor and a bypass 
capacitor connected between the junction between the choke and resistor and ground.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco