04-09-2019, 11:52 PM
Well crap! I re-stuffed the 4 electrolytic cans with new Nichicons and now I have hum that I didn't have before. All of the mil spec electrolytic cans were still very moist inside and were obviously doing a good job. After re-checking the wiring a dozen times and comparing it to the pics I took before disassembly, I know it is wired as before. Disconnecting individual sections and substituting with external caps does nothing to improve the situation. Increasing capacitance does nothing. Ripple voltage after the filter choke is a mere .027 volts, about the same as before the re-stuff. Negative supply dropped from just over -7 volts to -6.8 volts. Scratching my brain a bit here!! Radio still works great, just don't like the background hum.
