Power Triode
The 31 Vacuum tube is a power amplifier of the
three-electrode type. It has a coated filament which
takes as little power as possible consistent with
satisfactory operating performance. This feature makes
the 31 tube particularly suitable in battery-operated
radio receivers employing the 30 tube, 32 tube and/or
34 tube where economy of filament current drain is
important. This tube was first developed by RCA in 1932.
Electrical Data:
Filament Voltage ......................... 2.0 DC V
Filament Current ........................... 0.13 A