GT1C GEC COLOSSUS VALVE, 1939

Used in the Colossus computer at Bletchley Park. During the rebuild of the first electronic computer in the world, engineers involved in the project were serching world wide for all the valves of this type they could find as the machine used several hundred.
It is an Argon filled electronic switch. This thyratron found many uses as a timebase for radars, and in particular many were used in the Colossus computer which was used a Bletchley Park to crack the codes of the German Lorenz cipher machines.

A0599