The POVT37B is a directly heated telephone repeater triode on the GPO bayonet base. The prototype was the E132 and it became the CV1643. The maker's name is etched into the dome.
The electrodes are mounted horizontally. The nickel plated base cap can be seen to have a locating pip on the left to guide the valve into the bayonet base.
The anode is bright and the grid extends well beyond the limits of the anode box. The filament is missing but a fragment of the oxide covered wire remains attached to one support. There are four supports indicating a pair of parallel filaments.
The grid is wound round two rod supports. The wire looks to be resting on the surface of the rods. If there are notches, they are very shallow.
The four pin base cap. The copper lead-out wires are wrapped round the pins and soldered.
Focus on the grid wire fixing.
The balloon envelope is 50 mm in diameter and, excluding the UV base pins, is 98 mm tall.
