Gunner Asch wrote in
:

On Tue, 25 Sep 2007 00:34:04 -0400, "Michael A. Terrell"
wrote:

clare, at, snyder.on.ca wrote:

Well, I've worked on an old battery set that, like a car
radio of the time, had a multivibrator to make the high
plate voltages from a lower battery voltage. IIRC the
main battery was 12 volts. Most of the "valves" or vacuum
tubes ran on either 12 volts or six (2 in series) but the
rectifier has a 1 or 2 volt filament.


I worked on hundreds of old radios in the '60s and '70s,
and still
have a lot of service data. The people on
news:rec.antiques.radio+phono have a lot more.

All I have ever seen used in a car radio was the 0Z4 gas
rectifier, or
a regular 6 or 12 volt filament regulator like the 6AX4 and
12AX4. A very few used a synchronous vibrator, and
eliminated the need for a rectifier. (Till the contacts
welded).


It used an "ignition"
battery - one of those that used to run doorbells,
fencers, and battery ignitions on some stationary engines
years ago. It was called the "F"ilament battery. I think
it was some sort of "farm" radio.


Farm radios were 32 volts, to run of the winchargers
used to charge
the batteries for lights in a farmhouse.


I thought they were 48 volts? Hence our telephone systems
still run 48 volts talk battery.

Gunner



Nope...32 volts. I have my grandmother's 32 volt Delco
radio. Still works! They had a wind carger, and shelves of
glass-jar batteries in the basement...before REA came
through.

Ken