[Amps] Question about 4-1000A operation

[Robert Groh]

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?

73
Bob, WA2CKY