Sensibly equivalent¶ to:
The 63SPT was A C Cossor's type designation number for the EF50s that it made and this example is a UK product and features black paint on the aluminium can.
We also have a 63SPT made in the US for Cossor.
The valve was so important during WWII that several manufacturers were involved although the design was a breakthrough for Philips in The Netherlands.
The plain aluminium screening can.
The wide metal tube envelope is 34 mm in diameter and, excluding the B9A base pins, is 59 mm tall.
References: Datasheet & 1043. Type 63SPT was first introduced in 1939.
Absolute Maximum Operating Conditions¶
Updated September 28, 2018. shape:wide.glass.tube construction:all.glass type:pentode age:1930.1940 base:b9g heater:6.3v pins:9 pin:1.h pin:2.g2 pin:3.a pin:4.g3 pin:5.s pin:6.k pin:7.g1 pin:8.s pin:9.h