SQS Series Sonars

AN/SQS-1

Frequency: 20 – 28 Khz
Pulse Length: 12 or 36 ms
Pulse Power: 30 kilowatts
Beamwidth: 19° x 16°
Scanning Rate: 90 cycles
Range Scales: 1500, 4000 and 6000yd range scales.
Notes: Entered production in November 1952. 236 produced

AN/SQS-4 Mod 1

Frequency: 8 Khz
Range: 5,500 yards

AN/SQS-4 Mod 2

Frequency: 10 Khz
Range: 4,500 yards

AN/SQS-4 Mod 3

Frequency: 12 Khz
Range: 4,500 yards

AN/SQS-4 Mod 4

Frequency: 14 Khz
Range: 4,500 yards
Pulse Lengths and Pulse Powers: 6 ms (50 kW), 30 ms (30 kW), 80 ms (10 kW)

Note: This was actually the original version.

AN/SQS-7

Frequency: 12 kHz
Pulse Lengths: 3 ms (50 kW), 10 ms, 30 ms, 60 ms
Beamwidth: 20° x 20°
Range Scales: 2500, 5000 and 10,000 yards

Notes: VDS version of AN/BQS-3. Tested in 1953, but not adopted.

AN/SQS-10

Frequency: 20 kHz
Pulse Lengths and Pulse Powers: 6 ms (50 kW), 30 ms (10 kW), 80 ms (3 kW)
Beamwidth: 19°
Scanning Rate: 150 cps
Range Scales: 1000, 3000 and 6000 yards

Notes: Specified for Destroyers, Escorts, and ASW conversion (DDE), along with the Tang Class SS.

AN/SQS-23

(Photograph of AN/SQS-23 on DD-850 Joseph P. Kennedy Jr.)

Frequencies: 4.5 kHZ, 5 kHZ, 5.5 kHZ
Pulse Lengths: 5 microseconds, 30 microseconds, 120 microseconds
Beamwidth: 9.25 x 9.25 deg; could be varied and widened vertically.
Scan Coverage: 300 degrees (theoretically, it has 360, but stern baffles limit it to 300)
Scanning Rate: 150 cps
Range Scales: 1,000, 2,500, 5,000, 10,000, 20,000 and 40,000 yards.

Notes: First installed 1958. 197 sets produced. Is the “10,000 yard sonar” associated with ASROC.