Method to localise faults in carrier frequency systems

摘要

1,064,592. Supervising repeaters. INTERNATIONAL STANDARD ELECTRIC CORPORATION. Oct. 8, 1965 [Oct. 15, 1964], No. 42759/65. Heading H4R. For the purpose of locating faults, a supervisory signal of increasing amplitude is applied to one path of a repeater system, and an amplitude-filter is provided at each repeater to transfer the signal to a return path when the amplitude is within a certain range in order to control an indicator. The amplitude-filters are similar; passing a range of about 0À4 Neper, and thus are operative in turn on account of the line attenuation as the emission level is increased. The two paths may be one a carrier path and one an audio path, or both may be carrier paths. The frequency employed for the supervisory signal is one that is not used for communication and is selected by a filter at each repeater.