Sensibly equivalent¶ to:
The VT52 was a particularly economical audio power valve (heater power = 1.26W) and was used where very large numbers of valves were required (eg. in telephone exchanges), consuming power throughout the night when nothing much was happening but it was essential for the whole system to be instantly ready for an emergency.
The commercial equivalent is the Mullard EL32.
As a single ended output stage the power is 2.8W, suitable for audio output in a transceiver. When operated in push pull the pair can deliver 7 W at 1.5% distortion. This could be used for a transmitter modulator for a low power phone transmitter and VT is RAF code for Valve Transmitting.
The reverse of the envelope carries the UK Air Ministry identification.
The classic envelope is 34 mm in diameter and, excluding the IO base pins, is 92 mm tall.
References: Data-sheet & 1043. Type VT52 was first introduced in 1940. See also 1940 adverts.
Absolute Maximum Operating Conditions¶
Updated January 03, 2022.