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ID = 32200
United States of America (USA)
Brand: Common type USA tube/semicond.
Developer: Western Electric Company Inc.; New York (NY) 
Tube type:  Reflex Klystron   SHF/EHF (>3 GHz) 
Identical to 707A = CV3589
Similar Tubes
Normally replaceable-slightly different:
Successor Tubes 707B   10AL1  

Base Octal (Int.Octal, IO) K8A, USA 1935 Top contact with a cap.
Was used by Radar
Filament Vf 6.3 Volts / If 0.65 Ampere / Indirect / Specified voltage AC/DC

The first American reflex klystron, intended as local oscillator in 10-cm microwave radar receivers. By the middle 1941 McNally of the Bell Laboratories had built the first samples of 707A, hence it was also known as 'McNally tube'. The production started by the end of 1941. It represented a true innovation, compared to the British types, the 'Sutton tube' and its derivatives, all operating at about 1700 V resonator voltage. The 707A could operate at about 300 V resonator voltage. In the 707A a close interaction between electron beam and resonating cavity was made possible by two mesh grids which became bright white in operation.

707A needs an external resonating cavity supplied by the customer, tuned over any range from 2.5 to 3.7 GHz.

707A was used as LO in the early 10-cm radar sets, as the SCR-519, together with 708A triode as mixer and 706A magnetron in the transmitter.

To an article on the development of early reflex klystron to be used as local oscillator in microwave radar sets.

Dimensions (WHD)
incl. pins / tip
30 x 135 x mm / 1.18 x 5.31 x inch
Weight 45 g / 1.59 oz
Information source -- Original-techn. papers.   
Tube Lore (II)   

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