The GE AN/GPA-73 Radar Course Directing Group (mobile version AN/CPA-73) was an air defense command, control, and coordination system of the United States Air Force. It was developed for the Electronic Systems Division 412L Air Weapons Control System (colloq. "AWCS 412L") for weapons direction (ground-controlled interception, GCI, by "Fire Direction and Control Equipment"). The AN/GPA-73 was used to create a "Base Air Defense Ground Environment" (BADGE II), for which Air Defense Command had recommended the system as "SAGE back-up (Mode Ill) control of BOMARC" in June 1958. When the GPA-73 was emplaced with the AN/FSA-21 Weapons Control Group computer for GCI, the system created a "miniature SAGE" military installation. The GPA-73 could also direct Project Nike surface-to-air missile fire from Nike Integrated Fire Control sites equipped with the "412 Target Designation System" in the Battery Control Van in a space allocated by February 1957 "behind the Acquition Operator [sic]". and the AN/GPA-73.

The 412L Joint Test Force was located at Myrtle Beach Air Force Base in 1963, testing revealed fragility that limited the unit to fixed emplacements, and "Tactical Air Command subsequently rejected the GPA-73 as part of its mobility forces." The 412L equipment supported "Det 1, 17th Air Force [in] the Allied Sector Operations Center III at Börfink", Germany, which had a nuclear bunker where on July 2, 1975, the 615th Aircraft Control and Warning Squadron temporarily stopped 412L operations [for] Constant Keystone modification." Sites with the AN/GPA-73 planned for the Alaska Semi-Automatic Defense System (ALSADS) were cancelled on January 26, 1960, and the last "operational 412L equipment" was used by USAFE in Germany.

In accordance with the Joint Electronics Type Designation System (JETDS), the "AN/GPA-73" designation represents the 73rd design of an Army-Navy electronic device for ground radar auxiliary system. The JETDS system also now is used to name all Department of Defense electronic systems.

Description

The GPA-73 included the following equipment (quantity in parentheses):

  • AN/GKA-10 & AN/GKA-11 Converter Groups (RCA)
  • AN/GKA-13 Monitor Transmitter Group (RCA)
  • AN/GKA-12 Receiver Group (General Electric Company — Defense Systems Department)
  • Data Processing and Display Subsystem AN/FSA-12 Detector-Tracker Group, Radar OA-3253 Track Data Processor OA-3254 Tracker Auxiliary Unit OA-3255 Digital Tracker OA-3263 Radar Detector OA-1723 Surveillance-Identification Group OA-3102 Surveillance Console OA-3103 Identification Console OA-3217 Radar Data Processor OA-3219 Surveillance-ID Data Converter OA-1724 Site-to-Site Data Link Group OA-3104 Data Link Central OA-3252 Battery Data Link OA-3327 Message Processor OA-3329 Coordinate Converter OA-1718 Height Data Group OA-3208 Height Data Display Converter OA-3209 Height Data Programmer OA-3403 Height Data Console [from "MPS-14 radar"] OA-3403 Height Data Console [from "MPS-16 radar"] OA-3216 Status Display Group OA-3233 Situation Projection Group
  • AN/FSA-21 Weapons Control Group OA-3161 Data Storage Unit OA-3162 Digital Computer OA-3179 (3) Weapons Display Converter OA-3183 (4) Weapons Control Console OA-3180 Computer Auxiliary Unit OA-3210 Ground-to-Air Coupler OA-3264 (2) Core Memory OA-3436 Tape Transport Unit
  • AN/FSA-23 Jammer Tracker Group OA-3223 Azimuth Tracker OA-3224 (2) Jammer Tracker Console OA-3227 Jammer Tracker Display Converter
  • OA-3232 Performance Monitor Group OA-3237 Performance Monitor Console OA-3393 Confidence Indicator Console OA-3422 Performance Monitor Display Converter ID-936 Site Equipment Status Display (Portable) Trouble Analyzer
  • Prime Power Group Power Supply Sets OA-3169 (4) Data Processing Power Supply
  • Communication Subsystem OA-3261 Crosstell Input Group Electronic Switching Center
  • Flight Control Package Subscriber Sets AN/TRC-24 R-278 R-361 T-217 BC-639 AN/FGC-25 AN/FGC-20
  • Ancillary Subsystem Temperature Control Group
  • Data Acquisition Subsystem AN/FSA-31 Radar Signal Processor OA-3247 Comparator OA-3250 Integrator

See also