The KT74 beam tetrode was produced WWII and was designed for use in the audio output stage of universal mains receivers that could operate on DC mains and so did not have a mains transformer.
The audio output was given as 2 W when the anode load was 5,000Ω and the cathode resistor was 300Ω.
The Osram eliptical paper label.
The classic envelope is 38 mm in diameter, and excluding the IO base pins is 85 mm tall.
Absolute Maximum Operating Conditions¶
Updated January 20, 2017. shape:classic construction:pinch type:beam.tetrode age:1940.1950 base:io heater:160ma pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g1 pin:6.- pin:7.h pin:8.k.bp