NOISE ELIMINATOR HAVING VARIABLE REPETITION RATE BREAKAGE AND*OR VARIABLE ELIMINATION THRESHOLD VALUE

摘要

A noise blanker circuit for a stereo radio receiver is disclosed herein. The noise blanker circuit detects noise impulses in a received radio signal. When the magnitudes of these detected noise impulses exceed a predetermined threshold level corresponding noise blanking pulses are produced which are coupled to a gate means. The gate means receives the received radio signal and selectively passes and blocks this signal in response to the noise blanking pulses such that the output of the gate means is essentially free of noise impulses. A manually adjusted actuator is provided for selectively altering the predetermined threshold level of the noise blanker circuit such that the most efficient mode of noise blanking can be implemented. In addition, rate shut-off circuitry is provided to prevent the production of noise blanking pulses when the detected noise impluses occur at a repetition rate exceeding a maximum repetition rate. The manually adjustable actuator is illustrated as comprising either the tone control actuator or the stereo-monaural selection switch actuator of a radio receiver. Another embodiment shows automatic threshold level and/or repetition rate selection linked to stereo signal indication.