>The way I was taught is that you key the amp with no drive and vary the
caps all around and look
>for a kick in the plate or grid current.
Also decrease the bias so the tube is running a fair bit of plate current -
say 1/3 to 1/2 rated dissipation so the gm is high.
Then if it's stable unloaded, as Carl says, it should be OK. Unless
(until?), of course, after time on 10 metres, the suppressor resistor cooks
and goes high, and the parasitics appear. Then it's conceivable that a
problem could exist leading to arcs on bandswitches and tuning caps. For
zero grid dissipation tubes, one could conceive of the parasitic then
leading to excess grid current causing the grid to melt - a scenario that
explains some of Rich's observations on ceramic tubes. A different scenario
to the flash arc effect, which does throw enough energy around to bend
filaments and grids.
73
Peter G3RZP
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