Being on this thread, why one can possibly need RF-actuated electronic
bias switching ? Could it be in order to save some power dissipated by
the final tubes, corresponding to the amount of idle current in between
the words? Come on! If the final amplifier needs this tiny margin, then
maybe its cooling system is not so reliable after all.
Would you trust, for instance, a RF-actuated TX/RX switching scheme, as
it is used in some VHF "brick" amplifiers ? I don't think so. Then why
trust bias to the same arrangement ? In my view, the only sensible way
is to interlock bias switching with TX/RX switching. Better yet, use a
sequencer similar to what's on G3SEK tetrode boards.
73 de Mike, YO3CTK
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