"Thats 1200W idle current for AB2!
Eimac recommends around 500-600W. Are you looking at the PP pair AM
modulator spec?"
I suppose the good news is that someone reads the stuff I write. I should
waht I send out, since 1200 watts indeed exceeds the plate dissipation of
the 4-1000. I can plead that I was simply a scrivener, reporting the facts
typed out in the 1972 Radio Amateur's Handbook. There are footnotes, but
none apply to the data quoted. So, nothing says two tubes, but it would
have to be. However, with Carl's data and mine, it appears that the
original question can be answered. Bias voltage should be around -60 volts
and would then be set for 150 ma, which is the 600 watts Carl mentioned.
The -200 volts on cw would be cutoff (or it could be higher) on standby.
Less plate voltage will require less negative voltage to set the proper
bias. Old tubes may require less negative voltage.
Good catch Carl! Wonder why the ARRL is giving us data for a 3 KW
modulator, and where is the 6 KW am rig construction article.
73, Colin K7FM
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