Special Features:

4 chan telephone circuit; 2 spiral 4 transmission line use; 200 hz to 12 khz carrier freq range; 1000 hz ring circuit; 400 to 800 mi oper dist; alt oper pwr rqmt ac 115v, 50 to 60 hz, 1 ph, 230v, 50 to 60 hz 1 ph, dc 12v; components list doc a tech man tm11-341 pg 142; sig telephone terminal set type tc-21-a and tc-21-b; genl purpose use

Properties:

Two or more carrier telephone terminals with operating accessories for two way communication. It may include necessary wiring facilities.