这是一个利用普通电话线在近距离无线发送语音信号的设备,可串行接入电话线上。当摘下话筒线路接通时就可用电话本身发送语音而不需要发射天线,也不需要电源(利用电话线作为天线,利用电话信号作为电源)。发送的信号在FM频带,可以用FM接收机在电话线附近接听。发射频率可以调整。 This is a device that uses ordinary telephone lines to send voice signals wirelessly at close range, allowing serial access to the telephone line. When the microphone line is turned off, the voice can be sent by the phone itself without transmitting the antenna or using a power source (using the phone line as an antenna and using the phone signal as a power source). The transmitted signal is in the FM band and can be picked up by the FM receiver near the telephone line. The transmission frequency can be adjusted.