07-07-2011, 05:14 PM
Well we need to work backwards from the speaker to the antenna, problem's somewhere in between. So if you still have B+ (measure it) and you create a buzz when touching the volume control center with a long test lead with the control all the way up, you know that you have power and amplification. That's half the set!
Then work backward testing voltages for each stage, and bear in mind that a digital meter will read higher, because it does not load down the circuit like old fashioned analog meters. Tons written about this already.
You did not mention whether you checked for out of tolerance resistors (open or more than 20% lower and most likely higher can be a show stopper depending on where in the circuit it is.) For a nickel apiece for most of 'em, I just replace them when doing the cap job.
Then again, you can measure the continuity of the windings of the IF Coils, antenna and oscillator coils, blast out the tube sockets with deoxit, and then attempt a realignment with a signal generator, if you have access to one.
Touch not anything ever when the set is plugged in. Just view your instruments, and be ready to power down quickly.
Well that should get you started.
Then work backward testing voltages for each stage, and bear in mind that a digital meter will read higher, because it does not load down the circuit like old fashioned analog meters. Tons written about this already.
You did not mention whether you checked for out of tolerance resistors (open or more than 20% lower and most likely higher can be a show stopper depending on where in the circuit it is.) For a nickel apiece for most of 'em, I just replace them when doing the cap job.
Then again, you can measure the continuity of the windings of the IF Coils, antenna and oscillator coils, blast out the tube sockets with deoxit, and then attempt a realignment with a signal generator, if you have access to one.
Touch not anything ever when the set is plugged in. Just view your instruments, and be ready to power down quickly.
Well that should get you started.