Using a 1N4007 silicon diode will work. The band end goes toward positive of electrolytic filter caps. Have filter caps been replaced? Are they also missing from the radio? Bad or missing you will get very low voltage readings.
Norm
:I am working on an RCA Ac/DC radio and have a question about obtaining 99v DC. The selenium rectifer was removed. Any body have any tips on a substitute for this rectifier. I tried a silicone rectifier diode IN4007 in place and still using the 33ohm resistor that is in series from the a/c cord.
:Only get about 21v dc. I hooked up a bunch of 9v batteries in series and the radio does work this way.
:Any ideas?