| 摘要 |
PURPOSE:To eliminate the 3rd harmonic in a stereo demodulation signal produced by a band pass filter of an intermediate frequency stage by providing a circuit cubing a double side band signal by a sub signal in an FM demodulation signal so as to correct the FM demodulation signal by an output of the said circuit. CONSTITUTION:A double side band S1 by a sub signal is extracted from an FM demodulation signal SD by a double side band signal extracting circuit 2. This signal S1 is applied to a 3rd power circuit 4, where the signal is cubed and the level of an output S2 of the 3rd power circuit 4 is adjusted by a level adjusting circuit 5. Then, an output signal S3 of the level adjusting circuit 5 is subtracted from the FM demodulating circuit signal SD by a subtraction circuit 3, and an output signal S4 of the substraction circuit 3 is applied to a stereo demodulation circuit 6 so as to obtain L and R signals. |
