02-11-2012, 08:25 PM
Well, today I tested the power XFMR, first with light bulb in series, then straight from the 110V outlet. It seems to be in a good health: the full-wave rectifier winding gives me 2x347.5V x 2 = 695V, and the filament voltage on the 80 rectifier gives me 5.6V, and the filament voltage for the rest of the tubes is 6.9V, which is all good.
The radio is missing the 80, but then I have one in my Philco 20, so I will probably use it for testing.
First I want to rebuild the electrolytic caps, then the bakelite ones. Especially important is one cap, dual 0.15uF, as one half of it is used as the Line filter, and those caps are not Y-rated, their age notwithstanding.
So, since I have no way right now to judge how much the rectified voltage will drop under load, I have to assume the worst case and buy 520V capacitors (this is, after all, the max. voltage of the orig. caps, their working voltage being 450V).
Actually, what I have is several good caps, from the samples I used for developing that switching supply, 56uF 400V. Two of them in series will make an excellent 28uF 800V cap, and it should do the trick.
Wish me luck.
The radio is missing the 80, but then I have one in my Philco 20, so I will probably use it for testing.
First I want to rebuild the electrolytic caps, then the bakelite ones. Especially important is one cap, dual 0.15uF, as one half of it is used as the Line filter, and those caps are not Y-rated, their age notwithstanding.
So, since I have no way right now to judge how much the rectified voltage will drop under load, I have to assume the worst case and buy 520V capacitors (this is, after all, the max. voltage of the orig. caps, their working voltage being 450V).
Actually, what I have is several good caps, from the samples I used for developing that switching supply, 56uF 400V. Two of them in series will make an excellent 28uF 800V cap, and it should do the trick.
Wish me luck.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.