This MVSG from Cossor has zinc loaded paint external screening.
Introduced in 1932, Cossor in 1935 describe the MVSG as a special variable-mu screened grid valve. The special feature being the control of volume by altering the grid bias. It is clear that variable-mu technology was still relatively novel.
Our other MVSG has a balloon envelope whereas this has an early shouldered envelope design.
The plain reverse with the connection of the paint to the base pins.
The classic envelope is 44 mm in diameter and, excluding the B5 base pins, is 119 mm tall.
References: Data-sheet & 1043. Type MVSG was first introduced in 1932.
Absolute Maximum Operating Conditions¶
Updated June 18, 2020. shape:classic construction:pinch type:tetrode age:1930.1940 base:b5 heater:4.0v pins:5 pin:1.g2 pin:2.g1 pin:3.h pin:4.h pin:5.k pin:tc.a