The MS4 from M-OV is described as a general purpose screened-grid valve for use in RF amplification in receivers. The valve was available in both clear and metallised finishes.
This exhibit is or later manufacture than MS4 as can be seen from the top cap connection. The 'tp hat' style replaced the screw cap arrangement.
The MS4B is a 'maximum gain' improvement and dates from the early 1930's.
The wire mesh is the screening grid (g2) and the anode consists of two small flat plates.
The classic envelope is - mm in diameter, and excluding the B5 base pins is - mm tall.
References: 1005 Type MS4 was first introduced in 1929.
Absolute Maximum Operating Conditions¶
Updated September 01, 2019. shape:classic construction:pinch type:tetrode age:1920.1930 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