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Hi Marshall. The voltages naturally would have been a bit higher with the silicons in there but I never allowed that to happen. I wanted to keep the voltages in that part of the power supply at the specified 310 and 120 so that is why I added the 300 ohm 50 watt resistor to that line. I suspect the previous variations were caused by the two 5U4's that are wired in parallel and support the 310 and 120 supplies. Tubes can vary as they warm up, even if they are new. The silicon rectifiers fix that. The single 5U4 that supports the 410 volts for the sweep circuits is not a problem because the overall loads there are way within the capability of the 5U4. And yes, one of the silicon rectifiers shorted which is what brought down the shop. One thing that puzzles me is I recently added a line fuse which should have blown, and it did not. The fuse was rated at 10 amps and perhaps I should have rated it at about 6 or 7. The puzzling part is that the inverter that powers the shop should have handled a 30 amp load which should have caused a 10 amp fuse to blow, and it did not. It is possible that the fuse is somehow out of range too. But that is not by any means a normal failure mode for any kind of fuse. They normally fail safe and their "trip" value decreases with age. Long story short, I will be replacing it with a lesser value before continuing.
Be back soon, Mike
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