| SK (radar) | |
| Country: | United States |
| Type: | Air-search radar |
| Introdate: | 1944 |
| Power: | 250 kW |
| Frequency: | VHF band |
| Range: | 160.9 km (86.9 nmi) |
| Manufacturer: | General Electric |
| Beamwidth: | 10° |
| Pulsewidth: | 5 μs |
| Precision: | ± |
| Azimuth: | ± 3 ° |
SK was an American-made air-search radar used during World War II by the United States Navy. Models included SK-1, SK-2 and SK-3.[1]
SK was a very high frequency search set for large ships. It furnished range and bearing of surface vessels and aircraft, and it could be used for control of interception. The set had both "A" and PPI scopes, provisions for operating with remote PPIs and for IFF connections, and built-in BL and BI antennas.[2]
With the antenna at, SK could detect medium bombers at altitude at 100miles. Range accuracy was ± 100yd and azimuth accuracy ± 3°. There was no elevation control, but elevation could be estimated roughly from positions of maximum and minimum signal strength.
Shipment for SK included spares, with tubes for 400 hours, and a separate generator if the ship's power is DC. SK was not air transportable.
SK had 10 components weighing approximately . The heaviest unit, at, was the antenna assembly. The antenna measured x . It was mounted or more above water. The minimum operators required were one per shift. Primary power required was 3500 watts, 115 volts, 60 Hz. The source of power is ship's power of 115 volts, 60 Hz.
During the later stages of World War II, a parabolic antenna called SK-2 replaced the SK-1.[3]