Anyone have an idea of a favorite failure mode that would cause visible and
audible arcing in the tube compartment? I'm trying to repair one. Put 10 or
20 watts drive to it with the tune controls at nominal settings, you get
maybe 400 mA plate current. Then as soon as you start rotating the tune
control...Zap! Followed by blown fuse. And blown grid meter shunt resistor.
There's no visible damage, except the varnish is peeling in a few places on
the plate choke. It doesn't look burnt or anything, but does that indicate a
choke problem? Or just old age?
>From what I've read on this reflector before, bad parasitic suppressors
would be my first guess. But the benefit of your experience will be
appreciated. I don't have a garage full of spare tubes, chokes, and other
parts that I can swap in so I'd like to go with the best odds before I start
buying stuff to try.
73 and thanks,
Carl WS7L
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