[AMRadio] 813 Triode Connected Bias question.

Paul Baldock paul at paulbaldock.com
Fri Mar 20 18:15:37 EDT 2015

I am building a 2x813 pp triode connected modulator. This means the 
screen grid and control grid are connected together for each tube.

I haven't found any characteristic curves for the 813 in this configuration

On a sample of one, with 0 volts on the grid I measure about 40mA 
Idle Current (single tube). 40mA means about 100W per tube. Does 
anybody have a guess at what negative bias I would need to reduce 
this to around 20mA?


- Paul  KW7Y

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