Diversity radio telephone system suitable for service vehicles - provides signal and noise level detectors and comparators for each receiver

摘要

This installation has a number of fixed receiving stations, each of which is situated at a distance from the others. All the receivers are tuned to receive FM transmissions from one or more mobile units. The audio output of each receiver, is connected via a suitable channel e.g. a telephone line, to a central control station. Each signal is fed to a selection circuit which contains signal and noise level detectors and comparators. The best signal is amplified and switched, via the common output terminal to a loudspeaker.