> The Eimac spec sheets state a maximum of 2500 volts on the plate. My
> supply's lowest tap is at 2900 vdc at 500mA ccs. Is this dangerous to the
> tube to run the plate this high? I know with 3-500Zs many amps run the
> plates at 3800 to 4400 depending on the maker even though Eimac stated max
> Ep was 4kvdc. Tube worked fine and lasted a long time
I think what matters most is what the voltage is when on load. If your
amplifier has appropriate flashover protection, which can be as simple as a
50 ohm high power resistor in the EHT line, any flashovers that do occur may
not be fatal. I think Rich calls it a "Glitch" protection resistor, I call
it a surge protection resistor. It is an essential component curiously not
fitted to some commercial amplifiers.
If a valve is rated at 2500V, then it is expecting nearly 5000V across it at
the crest of the RF cycle. If your PSU has dropped to 2500V by that time,
then you are not going to exceed that - assuming proper tuning and loading
of course. If you get it wrong with 2900V it will probably do more damage
than getting it wrong at 2500V.
Mike
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