The sonar detecting-ranging set (sonar set) (Figure 1-10-9) is a lightweight echo-ranging, dip sonar capable of detecting and classifying moving and stationary underwater objects. The sonar set will provide information concerning range, bearing and speed, with automatic compensation for changes in water temperature and transducer rotation. The system is protected by a ganged three-phase AC circuit-breaker marked “SONAR” and two DC circuitbreakers marked “SONAR” (the 10 ampere circuitbreaker is for the sonar guillotine and the 7-1/2 ampere circuit-breaker supplies DC power to the sonar set) all located on the radio circuit-breaker panel. A 1 ampere AC circuit-breaker marked “DOME CONTROL” is located on the AC circuit-breaker panel. This circuit-breaker controls power to the dome
control.

The sonar set has three modes of operation; active, for echo ranging, passive, for sonar listening, and communicate, for underwater voice communications, with Bathythermograph (BT) recording facilities to provide the operator with information useful in the determination of optimum search depth. A secondary function is the generation of special test signals by Built-In Test Equipment (BITE) to provide various test modes for confidence checks on the system.