The 8P13A is believed to be a screened amplifier pentode introduced in 1938 and a variant of the 13SP. This version has the Ct8 base and the similar Mullard SP13C has a B7 base. The use would have been for IF amplification in radio receivers.
The classic envelope is 41 mm in diameter and, excluding the Ct8 base pins, is 101 mm tall.
References: Private communication. Type 8P13A was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated December31, 2012. shape:classic construction:pinch type:pentode age:1930.1940 base:ct8 heater:200ma pins:8 pin:1.m pin:2.h pin:3.h pin:4.k pin:5.g3 pin:6.- pin:7.g2 pin:8.a pin:tc.g1