1950's Zenith radio from an estate sale

[Captainclock]

I had a radio just like that, its a pretty common model, I believe its from the early 1960s, and the one I had like it worked pretty well too when I got it, except for the phono jack on the back, it seemed to have a bit of a hum to it when you hooked up an iPod or a tape player to it (its a line level phono jack meant for use with a mono ceramic cartridged record player) and I could never figure out why the phono jack on mine had a hum to it, I ended up junking mine out, and salvaging the tubes from it. It is a hot chassis design so when or if you do have to work on it unplug it from the wall (it has an interlock style plug so when you do work on it it would be dead anyways but that only means you shouldn't try using a cheater cord with it either unless you're done working on it and need to test it out, even then I would reinstall the plastic knobs so that you don't risk electric shock!)

[dieseljeep]

Originally Posted by Captainclock

I had a radio just like that, its a pretty common model, I believe its from the early 1960s, and the one I had like it worked pretty well too when I got it, except for the phono jack on the back, it seemed to have a bit of a hum to it when you hooked up an iPod or a tape player to it (its a line level phono jack meant for use with a mono ceramic cartridged record player) and I could never figure out why the phono jack on mine had a hum to it, I ended up junking mine out, and salvaging the tubes from it. It is a hot chassis design so when or if you do have to work on it unplug it from the wall (it has an interlock style plug so when you do work on it it would be dead anyways but that only means you shouldn't try using a cheater cord with it either unless you're done working on it and need to test it out, even then I would reinstall the plastic knobs so that you don't risk electric shock!)

Zenith radios of that type were designed properly and passed strict U/L standards. The tuner, bandselector, volume and tone control were isolated from the chassis, so the shafts wouldn't be hot, without the knobs. If the cabinet is on, there's no way to get shocked.
The phono jack has an isolating capacitor on the low side to prevent shock and minimize hum. After all this time, it was probably leaky.

[Captainclock]

Originally Posted by dieseljeep

Zenith radios of that type were designed properly and passed strict U/L standards. The tuner, bandselector, volume and tone control were isolated from the chassis, so the shafts wouldn't be hot, without the knobs. If the cabinet is on, there's no way to get shocked.
The phono jack has an isolating capacitor on the low side to prevent shock and minimize hum. After all this time, it was probably leaky.

That makes sense, but I definitely don't have that radio anymore so I couldn't look for that isolation capacitor and replace it, I still have the back cover of mine yet, but that's about it, once I get the cord off of it (so I can have a second cheater cord if needed) I'll just recycle the case.