Locating noise sources in communications channels - compares original and current pulse-echo measurement results and has auxiliary register

摘要

The method and measurement device are for locating sources of noise in communication channels and involves use of the pulse fault location principle whereby reflection times of impulses from noise points are measured and related to position. The pulse-echo method is developed to enable simple reliable detection of unauthorised connections such as tappings in telephone systems. The result of a first measurement is permanently stored as a time (distance dependent) an magnitude echo history for a defined channel. Later measurement results obtained by impulse echo testing the same channel are stored in an auxiliary register. Results of each later measurement are incrementally compared with those of the first measurement. Failure of the stored signals to agree triggers a display having the size and position of the noise source.