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Hunting down the short in a Motorola 61CA
#8

40 watt. It's also a clear bulb which means I can see the filament glow a bit easier. I'm not sure that's a good thing. I may be a bit over cautious, but I really don't want to pop another cap or hurt a tranny.

I did one more quick application of voltage...not long enough for a real warm up, but I let the voltage stabilize in stages as I ramped it up on the variac. All in, maybe 5-7 minutes to get to 100v or a bit higher. I only measured the voltage relative to the chassis at the CT (where the filter caps come together), and it seems way too low even without a longer warm up. I measured a -5.5v there...shouldn't it be more like a -25v? I wouldn't think I would make up the extra voltage with a proper warm up. Maybe I should wait to do more investigation until I get new tubes in that don't need a 5 minute or longer warm-up?

Charlie in San Antonio


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RE: Hunting down the short in a Motorola 61CA - by ccomer1955 - 08-21-2015, 10:57 AM



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