09-13-2009, 10:50 PM
I must admit I'm a bit lost reading the schematic around the cap pac that ties in with the volume control. The schematic and wiring diagram - even after printing on 11 x 17 paper - are difficult to read and I'm unsure about the voltage at the volume control. The cap pack looks like a tone control to me and I'm not sure how to size the resistors. [I think this is wrong. I've gone over other schematics and checked a reference book. Tone controls are frequently off the audio tubes. So, this is most likely part of the volume control that also filters 9/14/09] 166 volts and 3 milliamps makes 1/2 watt. I guessing that 1 watt resistors would be in order. I can't see how that part of the circuit could draw that much power but I'm a little short of confidence. With 2.5 M total and 970k max where the circuit taps in I'm looking at 65V and 1/4 watt resistors.
Back to the radio servicing book. I haven't had enough experience with the various parts of the circuit to know what to expect for typical voltage and current at the volume control and I'm starting to question what I'm calculating. It's getting late.
Back to the radio servicing book. I haven't had enough experience with the various parts of the circuit to know what to expect for typical voltage and current at the volume control and I'm starting to question what I'm calculating. It's getting late.