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UPDATE, JULY 25, 2019, DAY 355
LIGHTS OUT.
From Mike:
“Hi Marshall. Recently I have noticed that the power supply voltages are not stable at the voltages that they need to be at. There are basically 3 voltages supplied here. The Westinghouse prints call them to be 410 VDC and 310 VDC, and 120 VDC. The issue with the variations in voltage are simply design related. The 310 VDC supply is also supporting the High Voltage regulator circuits and the bias on that stage is critical. I was having problems with the High Voltage regulator becoming unstable and causing fluctuations in the high voltage setting. I decided to replace the two 5U4 rectifier tubes that supply the 310 VDC with silicon rectifiers. I added a 300 ohm 50 watt resistor in the system to keep the voltage at 310 VDC since the silicon rectifiers are more efficient than the 5U4’s. I also decided to keep the 5U4 that supplies the 410 VDC since that is mainly for the sweep circuits, and that is all working fine. I have also been working on the edge convergence and NOT having much luck with that so far. Tonight, as I was tinkering with that problem, one of the silicon rectifiers shorted and all the lights went out in the shop! Not sure why that happened yet. Possible, just a sporadic failure of the rectifier. I will review the specs on the parts that I used and continue with the progress. This edge convergence problem is next.
Cheers, Mike”
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