| 摘要 |
PURPOSE:To make common use the carrier wave current supply unit, by constituting the 60-communication line multiplex conversion unit by use with one type of modulation and demodulation circuit to make easy the maintenance of the modulation and demodulation circuit, and taking the same carrier as the carrier for the first supergroup modulation and the first to fifth group conversion, as the modulation and demodulation frequency. CONSTITUTION:The 60-communication multiplex conversion unit consists of the first to fifth modulation and demodulation circuits and the coupling circuit 6, the modulator 7, filter 8 having 672-720kHz pass band and modulator 9 are located at the modulation side of the circuits 1-5, and the carrier in 612kHz is fed to the modulator 7. Further, at the demodulation side, the demodulator 10, filter 11 having pass band of 672-720kHz, demodulator 12 and filter 13 having 60-108kHz pass band, are provided to give the carrier in 612kHz to the demodulator 12. The modulator 9 and demodulator 10 of the circuits 1-5 are given one wave length of the carrier 420-612kHz, the coupler 14 of the circuit 6 is connected to the modulator 9 of the circuits 1-5, the demodulator 10 is connected to the distributor 16 of the circuit 6 to constitute the circuits 1-5 with one type of modulation and demodulation circuit. |
