| 摘要 |
PURPOSE:To monitor emergent broadcast normally or intermittently, by transmitting the emergent broadcast identification signal through the use of subcarrier of audio multiplex broadcast control channel signal and detecting this emergent broadcast identification signal at the reception side. CONSTITUTION:A processing circuit 4 is a circuit outputting a signal E when the signal in 922.5Hz is present and a processing circuit 5 is a circuit outputting a signal F when the signal in 982.5Hz is present. Further, a logic circuit 6 is a circuit which outputs an emergent broadcast confirming signal G to a terminal 7 when the output signal D of a demodulator 3, i.e., the component of subcarrier B in 3.5fH is present and the output signals E, F of the circuits 4, 5 are both absent. Further, if the subcarrier B in 3.5fH not modulated with the control signals C1, C2 is transmitted, the signal D is present and the signals E, F are absent, then the emergent broadcast confirming signal G is output from the logic circuit 6. |
