Quote:
Originally Posted by Electronic M
I forget what the case was on my CT-100 (I think the previous owner addressed the power supply when they did a janky amateurish recap), but my 21CT55 (CT-100 factory modified to drive a 21AXP22) both ballast sections were open so I bought a couple of chassis mount high power resistors off mouser and found places on the rear upright where the resistor screw holes lined up with the cage screw holes. I gutted the original ballast and it now exists purely as decoration.
I also ended up replacing each selenium with 12 modern silicon diodes in series to emulate the original selenium voltage drop.
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It was a very good thing you replaced the selenium rectifiers with modern silicons, as seleniums can short and give off a very unpleasant-smelling gas when they fail.
I did not realize, however, that you needed to replace the selenium rectifiers with 12 silicon diodes, for a total of 24 silicons. I am thinking your TV used two selenium rectifiers, as a lot of 1950s TVs did; my folks' second TV, a Crosley Super V from about 1955, had two seleniums in the LV power supply. (Their first television, a 1954 RCA Victor 21" console, had a 5U4 LV rectifier, IIRC.) These selenium rectifiers, IIRC, were still good when we finally put the Crosley Super V in the basement in 1965 (where it, and the cabinet of the 1954 RCA, remained until 1972; long story and OT), replacing it with a Sears Silvertone all-channel 17-inch b&w portable shortly thereafter (at my mother's insistence, as she wanted an all-channel TV by this time; the reasons for that are OT for this thread).
Now that your TV has silicon LV rectifier diodes to replace those seleniums, you won't have any more trouble with the rectifiers for a long time unless they short again, giving you one less thing to be concerned about. However, this shouldn't be an issue; if the rectifier diodes short again, the TV's line fuse(s) or circuit breaker, of course, will open immediately, so you will know beyond the shadow of even the most unreasonable doubt that there is something wrong in the power supply.