Re: Polarity reversal

Posted by HH56 On 2019/10/27 11:40:29

Normally the stock Packard radios are not damaged with a reversal because anything polarity sensitive in the radio is fed by the internal voltage supply. That supply is generated by the secondary coil of a transformer and is isolated from the external supply. The external power is only on the primary coil side of the transformer which is energized by the vibrator. The internal supply has its own rectifier tube and will always stay the same polarity to feed the rest of the radio.

If the radio has been repaired, possibly the original vibrator was changed to a solid state version and those will be damaged or just not work. If the stock vibrator is still in the radio possibly it or another component just chose to fail at an inconvenient time.