"Fifteen diodes marked "PTC 2050" I have been unable to find any
to these. I removed one and tested it like
a zener, and never detected a breakdown voltage up to 35v, that's where
stopped. Might someone recognize...(etc.)"
Not to insult you, but most power diodes are pretty much the same kind
for this application (cathode bias in a GG amp).
You must use the opposite polarity that you use for testing zeners. Plus
to the arrow head. Forward drop should be on order 0.8 volts per diode.
73, Roy K6XK
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