Sensibly equivalent¶ to:
The VMS4 variable μ screened tetrode dates from 1931. It was designed for RF and IF amplification in broadcast superhet receivers.
This M-OV valve is badged as Marconi suggesting it was made for professional and not domestic use. The narrow tube before the flare would allow for a horizontal mounting with a chassis screen in just the same was as the original S625. Our other examples of the glass VMS4 and VMS4 lack this feature. We also have the 1933 Catkin version VMS4.
This is an early example with the screw down top connection. Later production used the top hat top cap.
The Marconi brand and Made in England.
The balloon envelope is 45 mm in diameter and, excluding the B5 base pins, is 126 mm tall.
References: Data-sheet & 1005 Type VMS4 was first introduced in 1931.
Absolute Maximum Operating Conditions¶
Updated August 21, 2020. shape:balloon 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