Re: Packard Radios

Posted by Richter12x2 On 2015/3/21 22:44:42

Yep! In fact, both radios actually have the switches already. Disconnecting that Intermediate Frequency (IF) section just gets rid of a lot of inductive noise from unshielded source wires.

Basically you'd get a low hiss when playing phono, but if you turned it up super loud and you were on-station, you'd figure out that hiss was actually the radio station being picked up by the inactive network - so the radio station you were tuned into was still playing, just wasn't getting amplified.

Disconnecting that wire from the IF tube in the Zenith just cut all power to that section, so the silence is clear as a bell now. Honestly there was probably a resistor to ground or something that I could replace, but it was easier to disconnect the wire than to find which one. When I say I isolated the wire, I just mean I wrapped the plug end in electrical tape so that it won't short anything else out in the radio from being loose - all you have to do is unwrap the tape and plug it in - takes about a half a minute on the Zenith.

In the Packard radio, you could surely just add a Single-Pole switch there, and use that to isolate your IF.