175th Radio Research Company

• Vietnam War Service: The 175th Radio Research Company (RRC) was a U.S. Army signals intelligence (SIGINT) unit that served in Vietnam, primarily supporting the Military Assistance Command, Vietnam (MACV). • Origins: The unit was originally activated as the 175th Army Security Agency (ASA) Company before being redesignated as the 175th RRC in 1966. • Primary Mission: The 175th RRC’s main role was intercepting and analyzing enemy radio communications, providing crucial intelligence on Viet Cong and North Vietnamese Army (NVA) activities. • Stationed in Bien Hoa: The company was based at Long Binh Post and Bien Hoa Air Base, two major U.S. military installations in South Vietnam. • Covert Operations: Unit members often operated in plain clothes, blending in with civilian workers to avoid drawing attention from enemy agents and spies. • Close Coordination: The 175th RRC worked closely with other intelligence organizations, including the CIA, South Vietnamese ARVN intelligence, and allied units. • Use of Advanced Technology: The company employed state-of-the-art radio interception and direction-finding equipment, often mounted on vehicles or aircraft such as the RU-8D Seminole. • Tet Offensive: During the 1968 Tet Offensive, the 175th RRC played a critical role in providing real-time intelligence that helped defend U.S. and allied installations. • Unit Nickname: The company was sometimes informally referred to as “The Listening Post” due to its SIGINT mission. • Legacy and Veterans: After the war, veterans of the 175th RRC formed active alumni groups, preserving the history and stories of their unique and often secretive service in Vietnam.