Sensibly equivalent¶ to:
The 13SPA is a screened amplifier HF pentode with external metallising.
The control grid is taken to the top cap for maximum isolation between input and output circuits. This valve was used in RF and IF stages of domestic radio receivers with a common heater chain and used for Universal AC/DC sets.
The grey cossor metallic paint seems to be overpainted onto a valve with gold metallic paint. The suspicion is that this a Mullard valve that has been re-branded.
The classic envelope is 42 mm in diameter and, excluding the B7 base pins, is 106 mm tall.
References: Datasheet. Type 13SPA was first introduced in 1934.
Absolute Maximum Operating Conditions¶
Updated April 06, 2015. shape:classic construction:pinch type:pentode age:1930.1940 base:b7 heater:200ma pins:7 pin:1.m pin:2.a pin:3.g3 pin:4.h pin:5.h pin:6.k pin:7.g2 pin:tc.g1