Circuit Designations

CIRCUIT DESIGNATIONS Circuit designations are characterized by a letter and number code. The 21JS4 primary battle circuit, for example, is identified as follows: the numerals 21 indicate the purpose of the circuit; the letter J denotes sound power; the letters S means general purpose (radar, sonar, and electronic countermeasures [ECM] information); and the numeral 4 indicates a particular station in the circuit. The same circuit in the auxiliary system is X21JS4. All auxiliary and supplementary circuit designations are preceded by the letter X. Supplementary circuits are easily identified as such because they have no letter after the letter J. Q14. What does the letter J mean in sound-powered circuit designations? Q15. How can you identify a supplementary circuit? The following are some typical shipboard sound-powered circuit designations: CIRCUIT DESIGNATION CIRCUIT TITLE JA 1JG JL 1JS 21JS 61JS 1JV 4JV JW JX Captain’s battle circuit Aircraft control circuit Lookout circuit Combat information center informa- tion circuit Surface search radar circuit Sonar information circuit Maneuvering and docking circuit Engineering circuit (fuel and stability) Ship-control bearing circuit Radio and signals circuit 3-11