04-16-2016, 11:12 AM
I pulled a schematic from Nostalgia Air and also a pin-out for the 42 tube from here: https://frank.pocnet.net/, so I wouldn't be guessing any more. I see I guessed wrong about a few things I wrote before. Sorry.
I can't tell from the schematic whether those voltages are right or not, but from the tube data sheet, they are right at the max, maybe because the field coil has less resistance than it should. The voltage at pin 3 should be higher than pin 2, which is what you have.
Next, check the voltages on all the other tubes. See if there is anything else in the service date that would give you clues to what the voltages and/or resistances should be. Sometimes there is a table of voltages or resistances. I don't have time right now to look it over, but I'll check back tonight.
I can't tell from the schematic whether those voltages are right or not, but from the tube data sheet, they are right at the max, maybe because the field coil has less resistance than it should. The voltage at pin 3 should be higher than pin 2, which is what you have.
Next, check the voltages on all the other tubes. See if there is anything else in the service date that would give you clues to what the voltages and/or resistances should be. Sometimes there is a table of voltages or resistances. I don't have time right now to look it over, but I'll check back tonight.
John Honeycutt
