[AMPS] Blown TL922A... What to do?

[Peter Chadwick]

I'll ask again:

What is the standard TL922 parasitic suppressor?

If it's the usual carbon resistor/shunt inductor, I could well imagine
parasitics starting after a period, as the resistor has probably got cooked.
Especially when we take into account Tom's comments on seal temperatures - I
presume he has evidence for that, or he wouldn't have said it.

Under those circumstances, a nichrome resistor may well perform better, in that
it doesn't cook and go high/open so easily.

As to the 'bangs' appearing because of parasitics, I am highly dubious. I could
see a parasitic causing enough heat in part of the tube structure to release gas
in a burst, causing an arc which cleans up during the following cooling period.
I can see a VHF parasitic causing enough grid dissipation to boil the gold off a
grid. And I have problems seeing the VHF parasitic circuit having sufficient Q
to get the step up to burn bandswitches.



73

Peter G3RZP



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