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ID = 33505
United States of America (USA)
Brand: Western Electric Company Inc.; New York (NY)
Tube type:  TR-switch 
Identical to 702B
Similar Tubes
Normally replaceable-slightly different:
  702A ; CV678
First Source (s)
1941 : - - Manufacturers Literature
Successor Tubes 729A   1B23  

Was used by Radar

Three electrode twin TR switch. The first TR switch was made in England around the mid 1941 at the Clarendon Laboratory. As switch it used the resonating horns of a Sutton early klystron, as the AM 10E/501, filled with low-pressure water vapour. A similar approach was followed at the Bell Telephone Labs., inserting gas in the electrodes of an experimental klystron device, the 712A, similar to 402A and forerunner of the 707A. The cathode and the repeller were then suppressed and replaced by glass caps.

702 was similar to 709A, but usable for longer wavelengths.

Improved version of 702A.

Information source - - Manufacturers Literature   

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