EMERGENCY WARNING SYSTEMS

摘要

Communications warning apparatus of the type wherein a transmitter is mounted in an emergency vehicle and one or more frequency-adaptive receivers are mounted in other vehicles. This system utilizes an FM transmitter coupled with recorder and play back mechanism in the emergency vehicle so that transmission can be effected in any of three modes, i.e. modulated C-W, voice transmission or repetitive recorded voice message, and transmission is effected at such frequency that all surrounding vehicles having a required receiver instrument will receive such warning or message preferentially over a receiver instrument or modular adapter utilized with a standard car radio.