Curious Zenith radio

[electra225]

This radio is advertised as a 4-tube 6-volt battery radio. The post even shows the sticker in the cabinet verifying that. However, the chassis has five tubes and a power cord. Anybody care to hazard a guess as to what's going on?

https://tucson.craigslist.org/atq/d/mar ... 50523.html

[19&41]

A teansformer changeout and the addition of a rectifier? I see no electrolytic filter cap though. Maybe it's secreted beneath the chassis?

[electra225]

I looked at the transformer on the chassis multiple times. It doesn't appear large enough to me to be a PT. I'd like to know the tube complement. Could it be possible that the tube heaters are in series? And that the transformer is the output transformer? Your suggestion of secreting the filter cap under the chassis is a good one, since a battery radio wouldn't have much in the way of filtering. Do you believe this is a converted battery radio, or an AC/DC chassis in a battery radio cabinet?

[19&41]

I think it's converted.

[TC Chris]

A 6-volt farm radio would have a vibrator and a power transformer. I don't see either. A regular battery radio would not need either because it would have ca. 90V B+ battery and a 6V filament battery. I need to look at the photos again to see if there's a model no. so we could examine a schematic.

Chris Campbell

[19&41]

I agree on the vibrator for a 6 volt set. It's cutout for it's socket would make a nice space for a rectifier and it's socket.

[TC Chris]

It's a 4-B-131, and if you look at the schematic, here:

http://www.nostalgiaair.org/pagesbymode ... 024815.pdf

you'll see a vibrator in the location of the right-corner tube shown in the photo from the ad. I'll bet somebody plugged a 4-pin tube into the vibrator socket. So it is a 4-tube vibrator-powered radio that comes with an extra tube and without a vibrator.

I recall that some have used a 12V CT transformer (6V each side of the center tap) running into the radio's power transformer to make these go. You'd need to deliver a clean-ish 6VDC for the filaments too. I haven't tried it myself except maybe once with a 6V Pontiac car radio long ago. So long I can't remember clearly. Still have the Pontiac radio and its big concentric-chrome-circle speaker & grille.

Chris Campbell