A short-base-line directional-antenna system consisting of three low-frequency/medium-frequency vertical antennas in a line on the ground, evenly spaced at a distance of about three times the length of the transmitted continuous wave; coverage is about 240° over long distances, in the form of 22 lobes; the lobes are areas where the signals corresponding to the Morse E and T are heard; these patterns rotate in space and the line of position is determined by counting the numbers of E's and T's that are heard.