BI-DIRECTIONAL COMMUNITY RECEPTION SYSTEM AND BI- DIRECTIONAL AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To suppress total noise and to prevent the loss in the head of a discrete up signal. SOLUTION: A down signal inputted from a trunk terminal 10 is amplified by a down amplifier 16 and it is outputted from a terminal side terminal 12. The up signal inputted in terminal 12 and discretely generated is amplified by an amplifier 26 and it supplied to the trunk terminal 10. An open/close switch 28 installed on the output side of the amplifier 26 to make the up signal pass or interrupted is. When the up signal becomes not les than a reference signal which is previously decided, a control circuit 30 closes the open/close switch 28 for a prescribed time. When the up signal becomes not less than the reference signal in the closed state, the closed state is extended for a prescribed time. The up signal is delayed by a delay circuit 24 for a delay time which is previously decided and it is supplied to the up amplifier 26.