Repeaters

GMRS began with a dream of radio for everyone. After World War II, inventor Al Gross demonstrated a pocket-sized UHF radio, and FCC Commissioner E. K. Jett championed a citizens radio service that would work almost like a telephone, quiet until someone called you. On April 10, 1947, the FCC created that service in the 460 to 470 MHz band and called it Class A Citizens Radio Service. The early gear was tube-type, limited to 60 watts of plate input power to the final amplifier tube, and it ran wideband FM with 50 kilohertz channel spacing.

For most of its early life, two meters belonged to AM, CW, and homebrew rigs with modest range. A mobile station might reach a few miles on its own, and then geography won. The idea that changed everything was borrowed from commercial radio: put a receiver and a transmitter together on a hilltop or tall building, let the receiver listen on one frequency and the transmitter speak on another, and suddenly a small radio in a car could be heard across an entire city. FM, already proven by police, fire, and taxi fleets, gave the system clean, quiet audio to carry.

Good news for Arizona GMRS operators: four Southwest Community Radio System repeaters are now open to any licensed GMRS operator, no membership required. Heliograph 700, Guthrie 600, Alpine 725, and Nutrioso 550 — all listed on myGMRS with their frequencies, tones, and coverage details — welcome any valid GMRS licensee in range. Just key up, identify with your callsign, and keep it courteous.