Leaving prevention method and leaving prevention functional attaching walky-talky device null of walky-talky

摘要

PURPOSE: To provide inexpensively a mislaying preventing function by checking a base band monitor signal and regarding it to be the occurrence of mislaying when any fault is in existence and sounding a warning tone from a speaker. ;CONSTITUTION: A control section 6A controls a synthesizer 5 to provide alternately a local oscillation signal to convert a radio telephone signal SRF or a monitor signal PRF into a base band telephone signal or a base band monitor signal. Thus, a reception section 3 provides an output of the base band telephone signal or the base band monitor signal alternately to the control section 6A. When the received signal results from the signal SRF converted into the base band, the control section 6A demodulates it and gives the demodulated signal to a speaker 8. When the received signal results from the signal PRF converted into the base band the control section 6A checks a level of it. When the level is a prescribed level or below, it is regarded that the slave set 13 is apart from the main body 12 and the control section 6A allows the speaker 8 to sound an alarm signal.;COPYRIGHT: (C)1996,JPO