Best bist: Applications of microprocessors: Probing transmission lines

A portable microprocessor-based instrument is said to save time and trouble in locating faults in an electrical transmission line. The instrument, which weighs only 35 pounds, sends a swept-frequency signal (made up of waves of various frequencies within a certain range) and then samples the reflections. A few minutes later a graph, indicating the magnitudes and distances of faults down the line, emerges from a printer mounted on the front panel.