| 摘要 |
PURPOSE:To allow a user to surely hear only a voice of a radio communication signal by interrupting a voice output of an external audio device when the radio communication signal is received while using the external audio device is in use and selecting automatically the output of the radio voice. CONSTITUTION:A radio communication signal received by a transmission reception antenna 2 is fed to a squelch circuit 6 via a transmission reception section 3, in which whether or not the received signal is a desired signal is judged and its output is fed to a control circuit 5. When the signal is the desired signal, a switching control signal 501 is fed to an external voice relay switch 9 from the circuit 5 to stop a voice output of an external audio device 10. The circuit 5 monitors the presence of the received signal based on information from the circuit 6 for that time and when the end of the signal is judged the signal 501 is fed to the switch 9 to release the interruption of the voice output from the device 10 and a voice output is sounded from an external speaker 12. |
