The 4030D is a high power water cooled transmitting triode. The filament is pure tungsten and operates at constant voltage to produce an emission of 45 Amps.
At the BBC regional medium wave transmitter at Washford Cross six 4030D valves were used in the STC CM10 200 kW transmitter. This transmitter was installed in 1950 to replace one of the two original 50 kW Marconi transmitter that had been at the station since its opening in 1933. The remaining 1933 transmitter remained as a stand-by until the end of the 1970s.
The wide glass tube envelope is - mm in diameter, and including the base pins is 1,320 mm tall.
References: Data-sheet & Washford Radio Museum. Type 4030D was first introduced in 1938.
Absolute Maximum Operating Conditions¶
Updated October 09, 2013. shape:wide.glass.tube construction:pinch type:triode age:1930.1940 base: pin: