VX3353 pulse modulator tetrode
The base is marked H, C, G and SG - presumably meaning heater/cathode, cathode, grid and screen grid. The above data is from an EEV data book.
This valve is marked VX3353 and No. 73 by hand on both sides of the metal flange.
The construction is unusual, almost as if the valve has been 'potted' in an epoxy shell.
This file was last modified
15:39:45, Tuesday September 02, 2014