First tested in 1965 aboard USS Gyatt and introduced in 1975, the AN/SPS-49 operates in the 851–942 MHz, or L-, band and has a range of 256 nautical miles (474 km). The orange-peel parabolic shape of the antenna creates a narrow 3.3°-beam to reduce the probability of detection or jamming. It can rotate at 6 rpm in long range mode or 12 rpm in short-range mode.[1] Default is at 12 rpm for the AN/SPS-49A(V)1, to provide more frequent scans against incoming missiles. The SPS-49A(V)1 can detect out to its full range at either 6 or 12 rpm. The antenna is stabilised to compensate for ships pitch and roll, to a maximum of +/-15° for both pitch and roll in 12 rpm mode, and +/-23.5° for both pitch and roll in 6 rpm mode. The output stage of the transmitter in all variants uses a two-cavity klystron amplifier.
In 1998, the Inspector General of the Department of Defense reported that SPS-40 and SPS-49 radars in Bahrain were "unusable because the equipment operates on a frequency that interferes with the Bahrain telecommunications services".[2]