Radio circuit quality supervisory system

摘要

PURPOSE:To discriminate the disconnection of the transmission lines of respective repeaters and faults in the repeaters by detecting an AM pilot signal which sets a central supervisory station to an initial stage in detection means in the repeaters consisting only of receiving elements and transmitting a detected result to a preceding stage. CONSTITUTION:The AM pilot signal from a pilot signal generator 10 in the central supervisory station 31 of the initial stage is inputted to a coupler 35 in the repeater 33 of the subsequent stage through transmission line 32, is detected in a BPF36 and a detection part 37 consisting only of the receiving element which operates even when a power is turned off, and the presence and absence of an envelope signal, which is the detected result, is transmitted to the supervisory station 31 of the initial stage through couplers 38 and 35. On the other hand, an input pilot signal passing through the coupler 35 is supplied to a similar repeater 34 of the subsequent stage through a coupler 40 and the detected result is similarly supplied to the supervisory station 31 of the initial stage through the repeater 33 of the preceding stage. Consequently, the disconnection of the transmission line is decided by the presence and absence of the envelope signal of every repeater and the power-off of the repeater itself by the no response of a data processing part 44 in the repeater at the time of detecting the envelope signal, and the central supervisory station can discriminate the faults.