The VMS4B variable μ screened tetrode. It was designed for RF and IF amplification in broadcast superhet receivers and was superseeded by the Pentode and KT valves.The envelope shape matches Mazda production rather than M-OV and so this was probably not made by M-OV.See also VMS4 for the earlier 1931 version.The classic envelope is 37 mm in diameter and, excluding the B5 base pins, is 103 mm tall.References: 1005 Type VMS4B was first introduced in 1933. See also 1933 adverts. |
