Sensibly equivalent¶ to:
The VMS4 variable μ screened tetrode design dates from 1931. It was designed for RF and IF amplification in broadcast superhet receivers. This exhibit is a later example employing the shouldered envelope to allow for a mica sheet to provide support at the top ov the envelope. The first VMS4 valves followed the pattern of the first single ended SG valves in having a waist above the base cap that extended to the point where the screen grid began within the glass. Thus it could be mounted horizontally through a metal plate or chassis for maximum screening. See S215.
The printed Osram name.
The classic envelope is 45 mm in diameter and, excluding the B5 base pins, is 119 mm tall.
References: Datasheet & 1005 Type VMS4 was first introduced in 1931.
Absolute Maximum Operating Conditions¶
Updated March 07, 2015.