Philips SDR314 manpack mobile (1953)

At the time of its introduction in late 1953, the SDR314/04 was described by Philips Telecommunication Industries as a “Portable F.M. transmitter/receiver for the frequency range 156-174 MHz (1.92-1.72 m). (…) The transmitter, which has a power output of about 150 mW, is capable of covering a distance of about 1 kilometer in densely built-up areas (i.e. highly adverse conditions), or about 3 to 5 kilometers in open terrain.”