Sensibly equivalent¶ to:
The 63SPT was A C Cossor's type designation number for the EF50s that it made. This is a British made example and 63SPT is one made in the USA for Cossor.
The 1952 advert features this can style and this exhibit is probably from 1952 - near the end of the time the EF50 was being used and long after the EF80 and EF91 had taken over as the RF valve of choice for 45 MHz applications.
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 painted reverse of the screening can.
The wide metal tube envelope is 33 mm in diameter and, excluding the B9A base pins, is 60 mm tall.
References: Datasheet & 1043. Type 63SPT was first introduced in 1939.
Absolute Maximum Operating Conditions¶
Updated February 03, 2017. 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