Abstract: A non-destructive test system that displays time domain amplitude returns from multi-frequency, multi-phase, constant magnitude RF signals, that are reflected by differences in characteristic impedance of a wire over ground plane transmission line. The reflections are used to detect RF discontinuities or faults in conductive areas that form the ground plane which preferably are resolved using a generalized pencil-of-points algorithm. The nondestructive testing system so constructed is especially useful in testing field repairs of radar absorbing material (RAM) and other features of a conductive object or vehicle whose radar return is to be minimized.