Sensibly equivalent¶ to:
The VT-74 is the USA service code for the commercial 5Z4 and this exhibit carries both designations.
The metal octal valve type was introduced in America by RCA during the mid 1930s. The 5Z4 was designed to supply equipment of up to 40 Watts total power, this rectifier type was made by several manufacturers as it became very popular.
American service code VT-74 on the other side of the can.
The thin metal tube envelope is 25 mm in diameter and excluding the IO base pins, is 67 mm tall.
References: Datasheet, 1040 & 1043. Type VT-74 was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Updated October 25, 2013. shape:thin.metal.tube construction:glass.disc type:rectifier.fw age:1930.1940 base:io heater:5.0v pins:8 pin:1.m pin:2.h pin:3.nc pin:4.a(2) pin:5.nc pin:6.a(1) pin:7.nc pin:8.h.k