This valve from Cossor came in two versions, both electrically identical but with variations to the pin connections. The 'P' variant that we have here has the anode connected to the top cap. The other version the 'B' has the anode and g1 connections transposed so that the control grid is taken to the top cap. The latter configuration was the most favoured way of keeping the low level signal voltages away from the anode circuits.
The 4.TSP is an RF pentode designed for television reception.
The classic envelope is 41 mm in diameter and, excluding the B7 base pins, is 105 mm tall.
References: 1043. Type 4.TSP was first introduced in 1939.
Absolute Maximum Operating Conditions¶
Updated December13, 2012.