Ulster Radar was equiped with two area radars. The type 80 was located on site at Killard Point while there was a type 84 located close by on the airfield. Both radars were equiped with SSR (Secondary Surveilance Radar). In addition there were also height finders located on the unit. These were all owned and maintained by the RAF. In addition in late 1977 NATS (National Air Traffic Services) installed a free standing SSR located on the airfield.
This was a 2.5 Mw (peak) S-band (3 GHz or 3,000 MHz) search radar with a range of around 200-250 miles. The aerial reflector was 75 feet long and 25 feet high with a rotation speed of 4rpm. The transmitter power was somewhere between one and two and a half megawatts.
The Marconi Type 84 L-band radar operated on a wavelength of 23 cm. The magnetron developed a peak power of 2.5 Mw at a PRF of 250 pps and a pulse width of 10 uS. The Type 84 was originally designed for a 6 Mw magnetron, however problems with the magnetron meant that production had to go ahead with the 2.5 Mw magnetron. The head was a bit of a novelty, for the design allowed for two separate radar's working "back to back". In the original design the Type 84 radar was going use one reflector whilst the other was going to be used for a narrow beamwidth IFF Mk 10 SIF, this option was never installed though. The antenna reflector measured 60 ' wide by 21' 8" high with a rotation speed of 4 rpm
These were used as a pair in order to find the height of aircraft that were not displaying height read out on SSR. Care had to be used as the height finders, or "Noddys" as they were commonly refered to, would lock onto each other and spend time nodding at each other.
The editor would like to express grateful thanks to Dick Barrett, editor of www.radarpages.co.uk for the technical information and use of images and also to Doug Robb who took the Type 84 photograph. Further technical details on these radars can be found on the radarpages website.
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