b batteries
During the period of the pre-transistor era, (45's-60's), portable vacuum tube radio receivers were produced requiring the use of 2 or 3 separate batteries. One of these batteries, the "a" battery, powered the filaments of the radio tubes. The other, called the "b" battery, powered the anode (plate) and cathode circuitry.
b batteries by WesternPALcS November 16, 2007
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