The W61 is a post war variable mu RF pentode for broadcast receivers. The grid bias range is given as -3.0 to -25.0 Volts. Here we have the version with external metalisation of the glass envelope, we also have the plain glass version.
The Marconi branding of this M-OV valve.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 96 mm tall.
Absolute Maximum Operating Conditions¶
Updated February 06, 2015. shape:wide.glass.tube construction:pinch type:pentode age:1940.1950 base:io heater:6.3v pins:8 pin:1.m pin:2.h pin:3.a pin:4.g2 pin:5.g3 pin:6.- pin:7.h pin:8.k