Closed-circuit_radio
Closed-circuit radio
Radio that emits over a very small range
A closed-circuit radio is a radio that emits over a very small range, typically a college campus. This system can be achieved from two ways:
- By tying into the PA System[clarification needed][1]
- By using existing power lines, telephones lines, pipes, etc. to transmit a carrier current[clarification needed][2][3][4][5][6][7]