10-18-2014, 06:12 PM
OK, I think I'm on to something in the audio section. I have the pot in place, and wired back up with alligator jumpers. The plate voltage on the audio tube is 199v, and the schematic calls for 90v. I traced all the components where the plate ties into B+, everything seems good. It doesn't list a voltage for the grid, but I'm seeing -20.7 on the audio grid.
A few other voltages are off, but not all of these are in the audio section. not sure if the same issue causing my plate voltage to be high on the audio tube is causing these discrepancies as well.
Driver plate and screen: 183.1, s/b 225
Driver grid: -5.4, s/b 10
Magnetic Tuning plate: 195, s/b 230 (I flipped the magnetic tuning switch, didn't change the voltage)
1st IF plate: 192, s/b 220
2nd IF plate: 186, s/b 220
Also, the grid voltage on the output tubes is -59, but according to the schematic it should be +58. Not sure if that is just a misprint and it should be negative, or another symptom. All the other voltages I checked seemed to be +/- 15v or so from the schematic.
Any ideas?
A few other voltages are off, but not all of these are in the audio section. not sure if the same issue causing my plate voltage to be high on the audio tube is causing these discrepancies as well.
Driver plate and screen: 183.1, s/b 225
Driver grid: -5.4, s/b 10
Magnetic Tuning plate: 195, s/b 230 (I flipped the magnetic tuning switch, didn't change the voltage)
1st IF plate: 192, s/b 220
2nd IF plate: 186, s/b 220
Also, the grid voltage on the output tubes is -59, but according to the schematic it should be +58. Not sure if that is just a misprint and it should be negative, or another symptom. All the other voltages I checked seemed to be +/- 15v or so from the schematic.
Any ideas?
