AFB. the 728th TCS became later known as 728 ACS. Before the 728th, Duke Field was home to the 729th Tactical Control Squadron. In the 1970s, several TRC-97s were turned over to Air National Guard bases stateside. The 5th Tactical Control Group based at Clark Air Force Base in the Philippines used the TRC-97 extensively. The 5th TAC's mission was augmentation manning of SEA (Southeast Asia) radar installations. Many, if not most, of those missions were performed via TDY (temporary duty) support to Korea, Vietnam and surrounding areas during the Vietnam War. Most of these microwave links were used to provide communication links between the radar sites and the aircraft bases. The 5th Combat Communications Group at Robins AFB GA was also a major user of the TRC-97 supporting many missions, one of 3 Combat Comm Groups in the US (the 3rd at Tinker AFB and the 2nd at Patrick AFB) References Military.com Smithsonian/NASA ADS Physics Abstract Service Troposcatter in South East Asia David L. Boslaugh. When Computers Went to Sea: The Digitization of the United States Navy John Wiley & Sons, Apr 16, 2003 pg. 272 Military radio systems of the United States Military electronics of the United States Military equipment of the United States Microwave transmission