Sensibly equivalent¶ to:
This battery triode was designed in 1926 for the HF stages in broadcast receivers. The filament would be run from a 2.0 Volt accumulator.
The balloon envelope is 40 mm in diameter and, excluding the B4 base pins, is 82 mm tall.
References: 1931 data-sheet & 1043. Type PM1HF was first introduced in 1926.
Absolute Maximum Operating Conditions¶
Thanks to Andy Cowley for supplying the above PDF datasheet.
Updated December19, 2012. shape:balloon construction:pinch type:triode age:1920.1930 base:b4 heater:2.0v pins:4 pin:1.a pin:2.g1 pin:3.f pin:4.f