Packard Forum Index » Post-War (1946-54)

The radio in my 1948 Packard works fine until it gets hot.
When you first turn it on it goes thru its normal warm up of about 2 minutes and is fine. It has good volume and sound. After about 10 or 15 minutes the amplifier seems to overheat and quit working. It slowly loses volume until it is turned up all the way and can barely be heard. If I turn it off and wait 20-30 minutes it will repeat this cycle.
Does anyone have any experience with this? I suspect a tube or vibrator unit.

If you still hear the vibrator humming when the volume falls off chances are it is a tube. Could also be a resistor or capacitor opening or changing value when it heats up. Doesn't sound like something you can repair yourself without some testing equipt or at the very least another radio with a set of tubes.

There is a schematic on this web site-that gives voltages and etc at different points. I would also suspect a tube in the amp section. I think tubes can be accessed from the bottom of the radio. You can try that-most likely it will have to come out. Then you need a voltage supply etc for further testing. If you need a name there is a guy that advertises in the Packard mag well thought of. There is a guy here in Tn that works on them also. let me know if you need his name. Repair costs est $200. My radio did not work-pulled it found vib bad and bypass cap bad. Added some cap to gang cap