Billy, AA4NU and Gerald K5GW both I guess asked the
same question..
do I see any plate current due to bias when the amp
is keyed to transmit (even if no rf in)
I'll check that again tonight. My recollection is no.
It sounds like I need to check those zeners too? if
they are involved in the bias?
Yes I was pushing the output power for rtty duty
cycle. Between 1000 and 1200W. But I kept grid
currents low. 150mA or so?
hmm. I'm thinking back now.. I think maybe on 15M the
grid currents are a little higher. Most operation on
40M/20M so less on 15M.
How long? Well, 2nd day of the contest. But actually
in terms of long run periods, it wasn't during a
"worst case" sustained run period..
I think though it being 15M was more stressful.
I was monitoring temps, which didn't seem bad.
The problem with tube replacement seems to be
availability of the 3CX1200A7 ? (are there no China
3CX1200A7 replacements?)
I was nicer to the AL-80B afterwards. pretty quiet
fan in comparison :)
-kevin
ad6z
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