I picked up a Zenith H845 (or one of its ilk) in working condition. I'm surprised that there are two terminal screws on the back labeled "Stereo input." Anyone know what that is?

The radio has one 8" speaker and a 2" tweeter. According to the schematic for the C835 model, these stereo inputs connect directly across the tweeter.

It seems like it's not directly stereo... what is it?

Thanks!
Rodney

By the way, if it helps, the schematic I'm looking at is Beitman's 1960 pg. 175 for the C835 chassis 8C01 / 8C02.

The schematic says, "Stereo Spkr Terms / Coded speaker leads must be connected to coded terminals on speakers." Which doesn't mean much to me. Were these two terminals outputs or inputs from the point of view of the radio? On the back panel they are labeled "Stereo Spk'r Inputs." Were they really stereo (I can't imagine it)? If yes, don't they need a common wire somewhere too? Where does that get connected?

Anybody have an owner's manual for one of these radios?

Thanks,
Rodney

Back then, stereo was still a new thing. Phono and reel to reel tape were the only stereo medium. Many early stereo phonographs came with one set of internal speakers in the main cabinet and the second channel speakers were remote and sometimes optional. The stereo speaker input on your radio allows the radio’s speakers to be used as the second channel speaker set for a stereo record player. The terminals are coded for polarity or proper speaker phasing, a term that not too many people were familiar with back then.

Ah, that explains it. Thanks Doug! Did the radio even have to be turned on? Doesn't seem like it.

You can easily argue for a stereo with 2 speakers, or a stereo with no speakers. But a stereo with one speaker... that's a harder sell.

It makes me wonder if there was a matched-style phonograph to the H845, that used the same speakers and was designed to look like a left-channel unit to sit beside this radio, which to me looks more like a right-channel unit. Hmmm...

The radio would have been left off. The jack also doubles as an extension speaker output for the radio.

Some early plug and play stereo setups did not have identical left and right speaker systems. Some didn’t use identical audio amplifiers. Like anything else, stereo systems evolved.

Fearful of folks delaying purchase of new radios when television was just starting out, many radios had a "television" jack which would theoretically service the audio portion of a mute television (video only!) Don't know of any such beast ever made, except for some very nice tv/radio and sometimes phono sets.

Early stereo was a dog's breakfast at best and snake oil at worst. Sets and program material both.