Royal Thai Air Force Sgt. Sutthiphan Jankeeree (left) and U.S. Air Force Master Sgt. Joe Sitterly (right) communicate on AN/PRC-90 radios as part of Search and Rescue training at Khao Na Ting, Thailand, on 13 May 1996.
The PRC-90 radio is a dual-channel, self-powered, personal, emergency-rescue radio that is primarily used for two-way voice or modulated continuous-wave (MCW) communications between a downed crewman and a rescue aircraft. It has a provision for transmitting tone and swept-frequency, homing-beacon signals to guide rescue efforts. It operates on two fixed frequencies and is compatible with all UHF AM radios and UHF direction-finder groups.
The distances for line-of-sight transmission depend on a variety of conditions weather, terrain, or battery power. At 10,000 feet, voice mode is 60 nautical miles, MCW and beacon is 80 nautical miles, and auto direction finder is 50 nautical miles. On the ground, effectiveness is one-half to one mile or more, depending on terrain.
The newest generation of this radio is the AN/PRC-90-2. It combines the features of the AN/PRC-90-1 into a more useful design that closely resembles the original radio. The typical communication range is similar to the AN/PRC-90-1, but a high-power mode increases the voice range to 125 nautical miles at 10,000 feet. The -2 radio also is rated to operate in water 50 feet deep for five minutes or 2 feet deep for 24 hours.
The AN/PRC-90-2C and AN/PRC-90-T are training radios and operate on a radio frequency that will not interfere with normal search-and-rescue operations.