| 摘要 |
PURPOSE:To operate a pseudo stereo circuit in spite of FM reception or AM reception, by including a switching means which switches a main path and a stereo sensitivity correction circuit, a means which calculates the correlation coefficient of a demodulated output signal, and a means which controls the switching of the switching means corresponding to the value of a calculated correlation coefficient. CONSTITUTION:An FM broadcasting wave inputted from an antenna 20 is inputted to an FM stereo reception circuit 21 consisting of a frontend, an intermediate frequency amplifier, a detecting part, and an FM demodulation part, and is outputted after being separated to a right signal and a left signal. When a mode is set at monaural reception, the correlation of right and left outputs L and R that are the outputs of the FM stereo reception circuit 21 is taken to put out a stereo display lamp 23. At a correlation coefficient calculation circuit 31, the correlation degree of the L and the R is calculated, and the output is inputted to a microcomputer 37. The microcomputer 37 decides the correlation coefficient to control the change over switch 27 of a switching circuit.
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