Well, I've got a bit of a problem and would like some opinions. Another ham
tried out one of my 4-1000A tubes and reports the following:
Filament fine, tube lights up fine
He ran it with filament only for 4 hours and then applied 1500V to the plate
Result: no grid current
Another 4-1000A tube was tried in same circuit and gave 50 mA idling current.
I'm not sure what exact circuit he is using - probably grounded grid. No idea
of what screen voltage.
So it seems that my tube is no good. Any other possibilities we should try
before converting it into a table lamp?
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