ABC call signs and batteries
Roger Kirk
rogerkirk@ttlc.net
Tue Nov 24 16:10:43 EST 2009
Dan.Strassberg wrote:
> Except for crystal sets, which were powered by the
> signals they received, early 1920's radio receivers needed batteries
> (several different types in each receiver--filament, plate,
> screen--anyone else remember screen grids?) and I don't think
> rechargeable batteries, which probably would have had to be lead-acid
> batteries, were popular for use in radios. I guess that radio
> batteries were typically zinc-carbon
The "A" battery was for filaments. Typically big and supplied a lot of
current. (Predecessor to today's "AA" & "AAA") Frequently
re-chargeable and referred to as a "wet" battery.
The "B" battery was for Plate Power. Hence "B+" - Big, with multiple
cells for higher voltage & lower current. 90 Volts each and frequently
two batteries in series. Generally not re-chargeable & referred to as a
"dry battery"
The "C" Battery was for Grid Bias. Modest in size, 10 vots or under and
tapped between cells. Minimal current draw from the radio gave this a
longer life.
Most (if not all) of these batteries had fahnestock clips
(http://en.wikipedia.org/wiki/Fahnestock_clip)
For pictures:
http://en.wikipedia.org/wiki/Battery_(vacuum_tube)
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