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First FM Portable Two-Way Radio



1943: Connecting Soldiers in the Field

When the U.S. Army Signal Corps needed a longer-range radio for front-line troops, Galvin Manufacturing Corporation responded with the SCR300 model, the world's first FM portable two-way radio.

A need for military FM radios

During World War II, the U.S. Army Signal Corps undertook a series of tests to settle the debate whether AM or FM radios had better voice quality over distances. They tested radios that were exactly the same except for AM or FM circuitry under the same field conditions. They concluded that the quality of voice transmission over FM was superior to that over AM. With FM, the signal was not subject to static interference from motors or other electrical sources.

To a radio operator in a fast-moving tank or jeep, this was a wonderful improvement over AM sets that were nearly useless in these situations. To the foot soldier, FM meant clearer communications on the front lines. And to have a radio that was both FM and portable was "the infantryman's dream."

Building on experience

Galvin Manufacturing Corporation, which already was experienced in building Motorola FM mobile two-way radios for police cars, submitted an FM portable radio for testing. The model SCR300 radio, designed by Daniel E. Noble to work in the very high frequency (VHF) band, proved superior over other manufacturers' radios.

The 35-pound (15.9-kilogram) backpack radio had a range of 10 miles (16 kilometers) or more, could be tuned to various frequencies within the 40-48 MHz range using only one pair of crystals, and had remarkable frequency stability.

The SCR300 radio also met military requirements including simplicity of use and assurance that the time of day, weather conditions and geographical location would not affect the range of the signal.

World’s first FM portable two-way radio

The SCR300 radio, the first and only portable FM radio used by infantry soldiers, was used widely throughout Europe and the Pacific. The walkie-talkie, as it was called, provided critical radio links at Anzio, Guadalcanal, Iwo Jima and Normandy. One general declared that the SCR300 radio was the most useful communications radio employed in the Battle of the Bulge, and helped turn the tide of battle in favor of the Allies.

Beginning production in 1943, Galvin Manufacturing Corporation made more than 45,000 units before the war ended in 1945.