RELAY SYSTEM FOR CATV AND ITS RELAY AMPLIFIER

摘要

PURPOSE:To prevent signal interruption of a transmission line at downstream to a faulty location by bypassing an amplifier when a signal level of its output terminal is decreased abnormally and increasing the amplification factor of the amplifier when a signal level to an input terminal reaches an abnormally low level. CONSTITUTION:When an amplifier is faulty, a through-means is active and a signal inputted in a level of 70dBmuV is not amplified but sent as it is. Then double amplification is implemented in an amplifier of a next stage to keep a signal level of a normal transmission system. When the relay amplifier 12 is faulty, the through-means is active in the relay amplifier 12 is active and a fault signal amplifier means of the relay amplifier 13 is active.