I have a J-64 that I have recapped and has been working well for a couple of years. Now, however, if I am listening to stations lower than 1200kc the station eventually fades and the radio is quiet. If I turn the radio to a frequency higher than 1200 it makes noise again until I tune it down again - then it eventually cuts out. I am guessing it is the oscillator even though the tube tests good on my tester. I am going to try replacing it unless someone here can point me in another direction. Thanx for any help.

Dan Lejnieks

It does sound like the 6SA7 is the problem. A lot of those seem to develop shorts. If you tap on the tube, it may clear for awhile.

Gassy? Gassy tubes can test good, but often malfunction as oscillators, since the tube's function will be affected by the ionization of the gas.

Could also be a drifted resistor either feeding power to the oscillator circuit, or in the oscillator circuit itself.

T.

Thanks!!

I have some new tubes coming. I will let everyone know what happens.

Dan

Changed the 6SA7 and now everything is working again. Thanks everyone!

Dan