[Amps] Output Coupling Capacitors: Failure Mode?

[Vic K2VCO]

EP Swynar wrote:

> Subsequent testing here this afternoon indicates that the dropping RF output
> condition is now gone, thankfully! I have no idea what such a large
> inductance in the plate circuit might do to the efficiency of this amplifier
> on higher bands, like 10- or 15-meters...but my main focus for now is 160,
> and it seems to be happy "as is" on the band, for the time being.

You are lucky if you found a large choke that doesn't have any series 
resonances near the higher ham bands. If it does, it will soon be 
'zorched' like the old one! Temporarily short the choke with a clip lead 
and check with a grid dip meter for resonances. It's hard to get a choke 
that has enough inductance for 160 meters without finding resonances in 
or near the higher bands.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco