|
Dave - I did the same thing to a Zenith H845 Interlude (I had two) that I gave to a co-worker. The radio was also never really serviced and has the original tubes. I did however have to repair one of the silver-mica wafers in one of the IF transformer cans. It sounds better than any AM/FM set I can think of as well!
I disconnected the selenium and installed a standard 1N4002 in place of it. I later checked the voltage (@ 123 VAC line) and measured exactly 140 volts per the Sams schematic. The current was about 80 ma, slightly less than schematic.
So....Just to be careful, I inserted a 22 ohm, 7 watt in series with the silicon rectifier.
This dropped it a volt or two, but allows for a voltage drop at turn-on until the first electrolytic charges.
I also added a fuse, CL90 (120 ohms cold) thermistor and changed the wax-paper caps. Since the 4-section electrolytic seemed to be OK, I left it alone. It was about two months later, my co-worker sheepishly asking about the worsening hum, that I opened it up and finished the job by cutting leads and inserting new electrolytic caps in. So far, so good.
|