| 摘要 |
PURPOSE:To prevent missing of speech head of a voice signal by detecting an input voice signal so as to bring the mode to the transmission mode and also applying said voice signal to a transmitter via a delay circuit having a delay time from the start point of time to the end point of time of a control signal. CONSTITUTION:A voice level and a reference level EREF are compared at a detection circuit 3 and a detection signal Sd is generated at a point of time t1 when the relation of voice level > reference level EREF exists. Thus, the mode is brought into the transmission mode for a personal radio main body 4 from the reception mode at the point of time t1. At the transmission mode, a control signal SC is transmitted automatically from the personal radio main body 4 as shown in Fig. D. On the other hand, the voice signal SA from a microphone 1 is delayed by Td via a delay circuit 5 and the signal is fed to a voice input terminal 4b of the personal radio main body 4 from the later point of time of the end point of time t2 of the control signal Sd. Thus, the voice signal SA is transmitted from the first part after the transmission of the control signal SC. |
