[Amps] Grid to Cathode Short

[Bruce Osterberg]

Good Morning:

I have a Tempo 2002 that uses the 3cx400/8874 tubes.  All of a sudden I 
have an extremely high swr when the amplifier is on line, (in fact I can 
not put it on line.)  Plate current is around .4 amps and voltage is 
2400VDC.  Grid current is around 10 MA and never increases.  The input 
to the Cathode is through two .003M capacitors in Parallel and an 
Inductor, nothing more.  I have removed all relays and fed the cathode 
directly and taken the output directly from the output and still the SWR 
is Bad.  Do I have a Shorted Tube, (tubes) how can I tell, Also can I 
run One tube if One is Shorted until another is Found.  Any Help would 
be appreciated.

73 Bruce N9BX