Zenith 701 - Just Got It

[Bob E.]

Originally Posted by Jeffhs

I just looked at the tube layout and instruction label on the bottom of the radio, and am wondering why it lists the specifications (in part) as "105-125 volts, any cycles . . ." What power line frequency was this radio actually designed to operate on, or could it actually work on any available power source regardless of frequency?

Some areas of the US were 50 Hz until the late 40's, and some rural areas (and places with Edison power) were DC early on. I have a Magnavox "Concerto" phono from 1936 that is listed as 117 Volts, AC or DC. It has five tubes (two 25L6, two 25Z5 and one 6C5 with the heaters in a series string...no transformer so it doesn't care about the incoming power frequency! I also have a Mills jukebox from the same year, and it also has the ability to run on DC. It uses 2A3's for outputs, though, and I haven't looked the schematic over yet to see how it does the job on DC. I think there are some connection re-configurations you have to make.

--Bob