Going way back in time, radios used 3 batteries
A Battery powered the filament, very few tubes had indirectly heated cathodes, the filament was the cathode because it was so much more efficient.? Some filaments were coated with barium or cesium [rare) for improved electron emission.
B Battery, for the plate. Typically 22.5 or 40V
C Battery, for bias, these went away when someone figured out you could place a low value resistor in the cathode to ground leg of the tube to produce a "negative" voltage for the grid.
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At various times the A, B, and C were combined, and, at other times the A and B were combined.
The A battery typically had the shortest life because filaments required more power then the plates.
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Note: "Battery" sizes, "D", "C", "AA" "AAA" have nothing to do with function.
There were "B" cells at one point. I think with the introduction of the "AA", the "A" and "B" cell went away, this would have been the late 1950s.
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I've read "A" cells are still used in Europe, they are combined in a single case to power small lantern batteries. [I've never been to Europe so I have no idea if that statement is accurate.]
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In the good old days, 1960~1970, US lantern batteries consisted of 4 "F" cells. A "F" cell was the same diameter as a "D" but longer. Today most US lanturn batteries use "D" cells
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An "AA" and "C" are the same length, I've wrapped tape around an AA so it's work in my wife's wall clock.?
I didn't feel like running out and buying a "C" cell. Hillbilly Engineering at it's finest. The "C" cell lasted about a year, the "AA" lasted about a year.
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Almost everyone is familiar with the rectangular 9V battery, at one time, 1960ish, there was a round 9V battery about the size of a "C" cell. It had more amp hours [ok mA hours] then the rectangular one but transistor radio design improved to where the extra capacity wasn't needed and the single double contact snap was easier for people to use. Heath offered a 100mW superheterodyne CB HT that used the round 9V battery. I was at an air show in 1964 or 65 [or 66 or 63] and a CAP member had to change the battery in his HT.
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Technobable nonsense. If you reversed the receive and transmit crystals for US CB channel 10, the HT would be on the CAP 'channel.' You'd have to retune the RF stages for optimal performance, but it was an inexpensive way for CAP members to get on the air. I had a Lafayette HT with a blown TX stage and reversed the CH 10 Rc and Tx crystals so I could listen to CAP. They were extremely active for a few years in Lexington, then sort of faded away.?
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.62 MHz
