| 摘要 |
PURPOSE:To prevent a digital signal from being a noise harsh to the ear and being outputted by sending only a digital selective call signal from a transmission side at first and sending a continuous tone squelch signal after sending of this digital selective call signal is completed. CONSTITUTION:A control circuit 5 is composed of a transmission switch 21, CPU 22 and continuous tone squelch circuit 23. At the time of transmission, when the transmission switch 21 is turned on, a transmission control signal is outputted from the output terminal 24 of the CPU 22. The output switching circuit 12 of a reception circuit 3 is tentatively turned off by the signal from the CPU 22 and an input switching circuit 16 of a transmission circuit 4 is tentatively turned off. In such a state, the digital selective call signal is outputted from a modulation circuit 17 according to a command from the CPU 22. When the transmission of this digital selective call signal is completed, the continuous tone squelch signal is outputted from the continuous tone squelch circuit 23. This signal is also amplified and originated from an antenna 1. |
