| 摘要 |
PURPOSE:To simplify the constitution of the titled device and to monitor normality by limiting a detected output signal level at a prescribed level by a limiter circuit and comparing the output signal with a threshold to discriminate whether a communication device is normal or not. CONSTITUTION:A signal from an input terminal 1 and a pilot signal from a pilot signal generator 2 are applied to an SSB modulator 4 through a buffer amplifier 3 and converted into a required transmission frequency band and an SSB output signal is outputted to an output terminal 7 through a BPF6. A part of the output signal is inputted to a detecting circuit 22 in a signal monitoring device 21 to detect the signal including the pilot signal. The level of the detected output signal is limited at a prescribed level by the limiter circuit 23 and its output signal is applied to a decision circuit 24. The decision circuit 24 compares the input signal with a threshold to decide whether the communication device is normal or not, and if the device is abnormal, an alarm signal is outputted from decision output terminal 25. Thus, the constitution of the device is simplified. |
