Jim,
I find it very odd. It affects the lower end of both the police band and the SW band. The high ends work fine. The part of the police band that has the problem is the same as upper end of the Broadcast band but the Broadcast band is unaffected by the problem. So it can receive the frequencies that the Police Band can't, while the problem is in effect.
I will try another tube. Thanks for your advice, Dave...
:Hello Dave,
:I am not familiar with the set, but having said that, maybe the first suspect should be the oscillator. You say the voltages are correct. There should have been a negative voltage measured on the oscillator tube, and it would be helpful to measure that ASAP, right after the set dies, in the "three minute" window. No neg volts...no oscillator. If that's the case, then try a new tube. Often "good tubes" are marginal in some oscillators. When oscillator troubles develop they usually show up on the higher frequencies first (like shortwave). But why your shortwave bands work OK on their higher ends, but not the lower ends is odd. I am sure others can add to this. Good luck.
:Jim |
Dave Froehlich 