Type 965 radar

During 1954-55, reports on most fleet exercises showed that there was an urgent need for radar picket ships. These would require a suitable radar. The need for such a radar had been raised as a staff requirement in May 1950. In 1955, four radars were considered: • The American AN/SPS-6C radar, which was credited with a range of at , and at . • The Dutch LW-02 radar, which was credited with a range of at . • A Marconi's Wireless Telegraph Company commercial design originally conceived for land-based air defence, which was credited with a range of at . • Extending the range of the Type 992 radar, by slowing its scanning rate. A potential route for the Royal Navy to get the SPS-6C was the Mutual Defense Assistance program (MDAP), but by 1954-5 the programme was running down. In addition, it was thought that getting spares for the SPS-6C radar could be a problem, because the United States Navy considered it obsolescent. The Marconi design was chosen and was named Type 965. The Type 965M was introduced in about 1960, and used the original AKE(1) aerial with an improved receiver and feeder. == Ships with Type 965 radars ==

in June 1973, with the Type 965M radar's single bedstead AKE(1) aerial on her mainmast.|thumb|right in 1972, with the Type 965P radar's double bedstead AKE(2) aerial on her mainmast.|thumb|right • Type 965M with AKE(1) aerial • The aircraft carrier HMS Ark Royal was given a Type 965M system on her foremast when modernised in 1958-59. • Type 41 Leopard-class frigates when modernised. • Type 81 Tribal-class frigates. • Type 12I Leander-class frigates (though removed in the eight ships given the Ikara conversion in 1970-78 and the five ships given the Seawolf missile conversion in 1978-84). • Weapon-class destroyers modernised to air direction destroyers. • County-class destroyers Batch 1. • The aircraft carrier HMS Centaur when refitted in 1963. The radar was taken from the air direction destroyer Battleaxe. • Tiger-class cruisers when modernised in the late 1960s. • The carrier HMS Hermes when converted from the aircraft carrier role to the commando carrier role in 1971-73. • Type 965P with AKE(2) aerial • Battle-class destroyers - the four that were modernised to air direction destroyers. • Type 61 Salisbury-class frigates when modernised in 1961-68. HMS Chichester had her Type 965 removed in 1973 when she was refitted as Hong Kong guardship. • County-class destroyer Batch 2. • The aircraft carrier HMS Eagle was given a Type 965Q on her lattice foremast when modernised in 1959-64. • Type 82 destroyer, the sole ship HMS Bristol described as "Type 965 with double AKE array and IFF". before it was replaced by Type 1022 radar when she was modernised in 1984-6. • Type 965Q with AKE(1) aerial • Type 965R with AKE(2) aerial • The aircraft carrier HMS Ark Royal was given two Type 965R systems on separate masts when modernised in 1967-70. • Type 42 destroyer Batch 1; Batch 2 had the Type 1022. == Technical specifications ==

A common aerial was used for transmitting and receiving. This was the single bedstead AKE(1) in the Type 965M, and the double bedstead AKE(2) in the Type 965P. The 965M and 965P were integrated with IFF Mk 10. The radar displayed both to an "office display unit" (monitor unit design 44), and up to six remote plan position indicator (PPI) displays. ;Differences between Type 960 and 965M • Type 965 receiver noise factor: 8 dB. • Type 965M receiver noise factor: 4.5 dB. • Type 965M feeder was 1 dB better than the Type 960 feeder. ; Range • Type 960: credited during appraisal as at . • Type 960: against an English Electric Canberra at . • Type 965M: at . • Type 965P: at . Type 965Q and 965R The receiver of the Type 965Q and 965R used "a coherent oscillator (COHO) to provide the coherence in phase between transmission and reception. The COHO is phase locked to the transmitter pulse." With the Type 965Q and 965R, the pulse repetition frequency (PRF) had a number of different settings. • In non-MTI mode, the PRF was set by the Pulse Synchronising Outfit RSE. • In MTI mode, to avoid interference from other radars, there were five available pulse intervals, each with a corresponding stagger time. Pulse intervals were ±3 μs; stagger times were ±2 μs. • 2580 μs pulse interval ±516 μs stagger time • 2590 μs pulse interval ±518 μs stagger time • 2600 μs pulse interval ±520 μs stagger time • 2610 μs pulse interval ±522 μs stagger time • 2620 μs pulse interval ±524 μs stagger time == Notes ==

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