The sonar receiver (Figure 1-12-3) mounted on the SENSO/Sonar operator station below the azimuth and range indicator processes sonar information for visual and aural presentation. Range and bearing information can be manually transferred to the ASN-123 through the senso control unit. Inputs and outputs for the sonar receiver are associated with the azimuth and range indicator, BT recorder, sonar transducer, dome control, and sonar transmitter. Further outputs are provided to the remote range and bearing indicator. A running time meter is mounted on the rear of the panel. The sonar receiver, control and indicator functions are as follows:

a. BEARING Display. A three digit display that indicates cursor circle bearing in degrees.
b. RANGE-YARDS Display. A five digit display that indicates the range of the cursor  circle in yards.
c. RANGE SCALE-KYDS Switch. In the number 1 position applies 1 kiloyard range signal to CRT sweep circuits, and built-in test equipment and automatically switches to low power when in active mode. The remaining positions apply either 3, 5, 8, 12 or 20 kiloyards signals to these circuits.
d. AUDIO Indicator/Push-button Switch. In the ONE position illuminates green and applies audio from the sector selected by the cursor, to the ICS. In the ALL position, the switch illuminates white and combines the separate nonharmonic tones received from sectors 7, 8, 1 and 2 with those received from sectors 3, 4, 5 and 6.
e. FREQUENCY Switch. In the number 1 position causes the sonar to operate at 9.23 KHz. In the number 2 position causes the sonar to operate at 10.0 KHz and in the number 3 position, the set operates at 10.77 KHz. In the SEQ position, the set  sequentially changes from FREQUENCY 3 to 2 to 1 between each transmission pulse.
f. TARGET Indicator/Push-button Switch. When extinguished applies range and bearing information to the receiver RANGE-YARDS and BEARING displays. In the VERIFY position, the switch illuminates green and applies range and bearing information to the receiver.
g. MODE Switch. In the SHORT position places sonar set in 3.5 millisecond echo-ranging mode. In the LONG position places sonar set in the 35 millisecond echo-ranging mode. The PASSIVE position places the sonar set in the listen mode. The COMM position places sonar set in underwater voice communication mode.
h. CURSOR POSITION Control. The CURSOR POSITION bearing control is used to control the bearing position of the cursor circle on the CRT and indication on BEARING displays. The white dot on the control indicates relative cursor bearing. The CURSOR POSITION range switch controls range position of the cursor circle on the CRT and indications on RANGE-YARDS displays.