| 摘要 |
PURPOSE:To attain solid writing and to improve the utility efficiency of a frequency without enlarging an azimuth angle so much by FM-modulating and recording a multi-level digital code. CONSTITUTION:A television signal is converted into the multi-level digital code in a multi-level converter 2, is FM-modulated in an FM converter 3 so as to record it. Thus, a spectrum concentrates on the side of the carrier and solid writing can be executed without a guard band or without enlarging the azimuth angle. Since the multi-level digital code is used, the utility efficiency of the frequency can be improved as much as the transmission S/N of a magnetic recording medium can be allowed. Since FM-modulation 3 is used, the transmission S/N is decided by a carrier C/N and a high-pass part with inferior transmission S/N needs not to be used so much.
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