BROADCAST WAVE RELAY AND MONITORING SYSTEM FOR BROADCAST WAVE RELAY

摘要

PROBLEM TO BE SOLVED: To provide a broadcast wave relay which can easily detect interference by a transmission antenna towards a receiving antenna and thereby can prevent oscillation and prevent an adverse effect on circumference and damages to equipment.;SOLUTION: Terrestrial digital broadcast waves received are input into a reception converting portion 24 from an RF input terminal 21 via a band pass filter 22 or the like and are converted into an intermediate frequency signal. Then, the intermediate frequency signal is amplified by an intermediate frequency amplifier 28 or the like and is mixed with a pilot signal output from a pilot signal generating circuit 35 and then is converted into a transmission signal having the same frequency as that of a received channel by a transmission converting portion 29 and is finally output from an output terminal 33 via a band pass filter 32 or the like to be transmitted to a target area. Meanwhile, a pilot signal detecting circuit 36 detects an interfering pilot signal from the transmission antenna towards the receiving side while the reception converting portion 24 outputs the signal. When the pilot signal detecting circuit 36 detects the interfering pilot signal, it stops the output operation of a squelch circuit 31 as well as displays an alarm on an alarm display portion 37.;COPYRIGHT: (C)2008,JPO&INPIT