Automatic squelch circuit with hysteresis

摘要

A radio receiver squelch circuit operative as a function of a comparison of the audio component level of the detected signal with the noise component level, so as to amplify and pass signals when the audio component exceeds the noise component by a predetermined ratio and to shunt the signals, thus squelching any output, when the noise component exceeds the audio component by a predetermined ratio. The circuit incorporates a hysteresis function such that the audio level required to initiate squelch is less than that required to break squelch.