| 摘要 |
PURPOSE:To attain sine wave S/N characteristic improvement reproduced by a converter and to evade a problem of cross modulation with a video signal by multiplying signals obtained by receiving/detecting sine wave/modulated video signals and reproduction sine wave signals and by reproducing regular NTSC video signals. CONSTITUTION:A sound signal 4 is converted into an intermediate frequency signal by an IF converter and then added to a mixer 8, and an output of the mixer 8 is converted into an RF signal by an RF converter 9. The system generates specific CH carriers in a data CH area by an oscillator 24, FM/modulates them by an FM modulator 25 using the sine wave signals generated by a sine wave signal generator 7, and transfers them through a cable 10 after mixing them with RF signals by a mixer 26. While a receiving side 2 receives carriers in the data CH area FM/modulated by the sine wave signals by an FM receiver 27 and reproduces the signals by an FM detection circuit 28. The system then multiplies these signals by the video intermediate frequency signals with a multiplier 20, and descrambles and converts them into the RF signals by the RF converter 23 to output them. |
