[RodB]

Hey Murf, this shouldn't be too difficult if it happens all the time. I'm assuming this is the 1938 Wells Gardner A2 with the Truetone label. You haven't said if you have any test equipment but if you can inject an audio signal either with an audio signal generator or your finger touching a small screwdriver at each grid point of the audio path you should be able to locate the culprit. I'm pretty sure if the output transformer has problems it wouldn't give the symptoms you describe.

So, tune in a station, if you place the vol control at the point where sound quits then touch the 6J7 grid cap at the top of the tube and you get an output noise from the speaker then the problem is the volume control. (Maybe it should be cleaned). I'd put my money (2 cents) it's the control.

You can also go the other direction. Start with the 6F6 output tube grids but they are harder to get to.