| 摘要 |
PROBLEM TO BE SOLVED: To shorten the reaction time of a voice squelch circuit and, at the same time, to eliminate the need of adjusting the circuit constant of the circuit. SOLUTION: This voice squelch circuit 3 comprises a reception level detecting means 6 which detects the level of received signals by detecting the level of carrier components and outputs the result of comparison between the detected level and a preset first threshold, a notch filtering means 31 which inputs demodulated signals and removes signal components having strong periodicity, and a voice level detecting means 32 which detects the level of the output signal of a filter outputted from the filtering means 31 and outputs the result of comparison between the detected level and a preset second threshold. The squelch circuit also comprises a squelch gate means 33 which controls the passage/suppression of the inputted demodulated signals based on the outputs of the voice level detecting means 32 and reception level detecting means 6.
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