AN/GPX-7

The AN/GPX-7 was a secondary surveillance radar (SSR) and Identification Friend or Foe (IFF) interrogator, operating in the L-band (990-1040 MHz transmit, 1080-1130 MHz receive) according to IEEE designation, or B-band by NATO designation. It was designed for IFF Mark X standard identification interrogations and was integrated into AN/FPS-3 through AN/FPS-20 radar systems starting in 1955. Utilizing an AS-295/UP slotted waveguide antenna measuring 222 inches (5.64 meters), its high peak power of 20 kW for a secondary radar often led to transponder overload at extended ranges. A modernized version, the AN/GPX-7A, featured a new OA-UIO/GPX-7A IFF/SIF coder/decoder with standardized 1 µs pulse lengths and a reduced transmitter pulse power of 1.5 kW.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/14.ssr/karte034.en.html