DISPLAY SYSTEM FOR INTERFERENCE DISTORTION VALUE CAUSED BY MULTIPATH DISTURBANCE OF FM RADIO WAVE

摘要

PURPOSE:To obtain a reproduction state of high fidelity by obtaining an indication value corresponding to a sense of hearing distortion by extracting only a signal component of approximate 19kHz in a signal outputted by a FM demodulator and then by displaying a multipath distortion value by its variation value. CONSTITUTION:A demodulated signal from FM demodulator 4 is supplied to narrow-band-pass filter BPF1 of 19kHz in center frequency, the output signal of which is supplied to high-gain amplitude limiting amplifier HAL to obtain a square wave of constant amplitude by converting. The output signal of it is applied to narrow-band-pass BPF2 of 19kHz in the center frequency of its passing band, thereby obtaining a sine-wave signal. The output signals of both BPF1 and BPF2 are processed by arithmetic circuit SUB to obtain an interference distortion component, which is converted by signal converter circuit SCC into a signal adequate for driving an indicator, so that indicator M will display its value. Consequently, the interference distortion can quantitatively be displayed which is caused by multipath disturbance of a FM radio wave.