| 摘要 |
PURPOSE:To eliminate wow and flutter components by recording a frequency- modulated signal on the 1st track of a magnetic tape and a carrier on the 2nd track and by obtaining the difference between both demodulated signals when they are reproduced. CONSTITUTION:An audio signal S1 is modulated by a frequency modulator 20 with a carrier S0 from an oscillator 10 and recorded on the 1st track. The oscillator output S0, on the other hand, is recorded on the 2nd track as it is. In reproduction, a reproduced signal from the 1st track is demodulated by a frequency demodulator 40 and that from the 2nd track is demodulated by a frequency demodulator 50. Both the reproduced signals are supplied to an operator 60 to find their difference and an output signal S7 is outputted. When a noise is generated owing to a wow and flutter during recording or reproduction, only the wow and flutter component is detected in the reproduced signal of the 2nd track, so the output signal S7 equals the said audio signal S1 from which the wow and flutter component has been removed. |
