Saturday, June 11, 2011


The AN/SPS-6C was a shipborne, long range, air and surface search radar, which was designed to supply target bearing and range data to its 5-inch A-scope indicator. In addition, as many as four, external, PPI indicators of the Radar Indicating Equipment VE, or Radar Repeater Equipment VJ or VK types could be attached to the SPS-6C. The RCN called this system WA meaning Warning Air. In 1947, the SPS-6 was granted AN nomenclature and the initial sets were procured from Westinghouse by the US Navy. Following quickly in 1947 were the 6A and 6B variants. The 6C and 6D versions were introduced in 1951, and the final 6E model in 1964.

The antenna of the AN/SPS-6C was a unidirectional, parabolic type reflector, fitted with a wind balancing vane and had a characteristic 30 degree cosecant pattern in the vertical plane. Horizontally, the beam width was 3.5 degrees. Its rotational period was 5 to 15 RPM in automatic mode and up to 2.5 rpm in manual mode. A dual feed horn on the antenna transmitted and received both radar and IFF signals. Overall weight for the antenna and its mounting pedestal was 924 pounds. The antenna itself weighed 591 pounds. Contrast that with the weight of the system cabinet which tipped the scales at 1,063 pounds. During the life of this system, there were four major American procurements. The first two were awarded to Westinghouse of Baltimore Md, the third went to AVCO Mfg/Crosley Division of Evandale Ohio and the final procurement was given to Stromberg- Carlson of Rochester, New York. Quantity and years of procurement by the RCN are not known at this time. HMCS HAIDA was fitted with AN/SPS-6C at the time she was paid off. It was originally fitted on her second tour of duty to Korea.

Frequency range: 1250 to 1350 MHz  
Power output:  500 to 750 kilowatts
Pulse repetition rate: one pulse rate is 150 pps with a pulse width of four  
microseconds. The other pulse rate is 600 pps with a pulse  
width of one microsecond. The pulse ratecould be varied  
+/- 10 percent from each of the two frequencies given  
above, by means of a calibrated front panel control.
Receiver type:  Superheterodyne type; 30 Mcs IF equipped with automatic frequency control and anti-jamming features
Range markers: the 'A' scope had range markers of 4, 20, 80, and 200 miles
Indicator types: the system was designed to interface to either VE, VF or VG type equipment
Power requirements: 115 or 440 VAC, 60 Hertz at 5.5 kilowatts