| 摘要 |
In the circuit according to the invention the entire FM-demodulator output signal is evaluated, that is to say the sum of the low-frequency signal and the d.c. voltage (AFC) component. The absolute value is produced therefrom and an attenuator circuit becomes operative in the low-frequency channel when the absolute value of the demodulator output signal exceeds a predetermined threshold value. This not only enables the suppression of spurious receptions, but also the suppression of intermediate receptions (the reception of two transmitters on the filter edges) and surging of noise. The circuit can be easily implemented in integrated circuit technique.
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