| 摘要 |
PURPOSE:To make it possible to recover the line rapidly at a fault time, by transmitting pulses of occurrence probability 1/2 to an autiliary line to stabilize the AGC of the repeater. CONSTITUTION:The receiving signal is equalized and amplified by amplifier 10 with AGC and is applied to discriminating circuit 11 and AGC control circuit 12. The output of amplifier 10 is applied to timing extracting circuit 13, and the timing is generated and is applied to discriminating circuit 11, and the output of discriminating circuit 11 is applied to discrambler 14, thus reproducing the original signal. The transmission original signal becomes a bipolar signal through scrambler 15 in bipolar output part 16 and is transmitted. The pulse train of occurrence probability 1/2 is normally transmitted to an auxiliary line to stabilize the output of control circuit 12 which controls the AGC of amplifier 10. Since the AGC of amplifier 10 is stabilized when the line is switched to the auxiliary line, line recovery becomes rapid. |
