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Ultra short wave telephone


The Army formally charged the Measurements Building in 1935 to develop a radio telephone equipment for field use with a range exceeding five to six km over a flat area with the antenna near ground level. More refined military requirements and experimental experience resulted in a series of five developmental models. Of particular interest was the application of new tube types in which the electrode system was mounted on strong straight pins penetrating the glass envelope.

The final Von Weiler model of the end of 1937 contained only four single function tubes and provided 20 consecutive telephony channels of 0,5 MHz wide each, the total centred around 199 MHz (wavelength 1,5 m).

In operation the transmitter-receiver was attached back to back to the power pack. The combination served as a base for a single antenna for transmission and reception. This set was adapted to industrial manufacturing in three transportable units and produced from the end of 1938 as Transportable set NSF type DR 42.

The German Army apparently continued the production during the occupation from 1941 and even in 1948 the equipment was considered as a viable proposition.


Transport by bicycle
(full size74 KB)

Clipping from daily paper Dec.1939
(ful size 97 KB)


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