Sensibly equivalent¶ to:
The 1626 was designed as an RF power oscillator in conditions of where good frequency stability is important. The operating conditions were to be class C and that explains the high negative grid bias. The valve was only designed to provide short pulses of power in the anode tuned circuit. The circuit itself would then ring and generate sine wave outputs.
Note that on the base is the US government code VT-137.
Recently this triode design has been pressed into service within an audio amplifier design.
The classic envelope is 36 mm in diameter, and excluding the IO base pins, is 89 mm tall.
Reference: Data-sheet. Type 1626 was first introduced in 1941. See also 1941 adverts.
Absolute Maximum Operating Conditions¶
Updated January 03, 2022.