In 1940,
Motorola (then the Galvin Manufacturing Company) received a contract from the
War Department to develop a portable, battery powered voice radio
receiver/
transmitter for field use by
infantry units. The project engineering team consisted of
Daniel E. Noble, who conceived of the design using
frequency modulation,
Henryk Magnuski who was the principal
RF engineer, Marion Bond, Lloyd Morris, and Bill Vogel. The SCR-300 operated in the 40.0 to 48.0
MHz frequency range, and was channelized. Along with other mobile FM tank and artillery radios such as the
SCR-508 (20.0 to 27.9 MHz) and the SCR-608 (27.0 to 38.9 MHz), the SCR-300 marked the beginning of the transition of
combat-net radio from low-HF (
high frequency) AM/CW (
amplitude modulated/
continuous wave) to low-VHF (
very high frequency) FM. Although a relatively large backpack-carried radio rather than a handheld model, the SCR-300 was described in War Department Technical Manual TM-11-242 as "primarily intended as a walkie-talkie for foot combat troops", and so the term "
walkie-talkie" first came into use. The final acceptance tests took place at
Fort Knox,
Kentucky in Spring 1942. The performance of the SCR-300 during those tests demonstrated its capacity to communicate through interference and the rugged quality of the design. Motorola was to produce nearly 50,000 of the SCR-300 units during the course of
World War II. The SCR-300 saw action in the
Pacific Theater, beginning in
New Georgia in August 1943. Colonel Ankenbrandt informed General Meade that "they are exactly what is needed for front line communications in this theater". In his point of view, the main difficulty was keeping them supplied with fresh batteries. The SCR-300 saw heavy use in the
Normandy invasion and the
Italian campaign. It also became "key equipment" that helped deter confusion in the
Battle of the Bulge. The British adopted the design of the SCR-300 for their own use from 1947 as the "Wireless Set No. 31". == Specifications ==