AN/TPX-17

The AN/TPX-17 was a secondary surveillance radar (SSR) designed for interrogating Identification Friend or Foe (IFF) systems. It operated in the L-band (IEEE designation) or D-band (NATO designation) at frequencies of 1010 MHz and 1110 MHz, with a peak power of 10 kW. The AN/GPA-8 designated its separate transmitter/receiver group, which included a broadside antenna array of 12 slot radiators that rotated synchronously with a primary radar antenna. Variants included the AN/TPX-17A, which utilized the reflector of the primary radar antenna; the AN/TPX-17B, which featured partial transistorization for enhanced reliability; and the AN/TPX-17C, equipped with a new coder/decoder for the IFF Mark X system.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/14.ssr/karte038.en.html