Abstract: Each competitor in a race is provided with a transmitter. At the finishing line, two receiving antennae (10,11) are mounted which, when the finishing line is passed, are responsive to the field of the corresponding transmitter and permit an accurate determination of the moment when the finishing line is passed. The two receiving antennae (10,11) are arranged so that their directional sensitivities are rectangular relative to each other. One of the two antennae is responsive to horizontal and the other to vertical fields. A signal (25) representing the passing of the finishing line is produced when the signal of the one receiving antenna (10) is above a high first threshold value (20) and the signal of the other receiving antenna (11) is below a low second threshold value.

Abstract: In this system for determining the moment when competitors in a race pass the finish line, each competitor is fitted with a transmitter. Arranged at the finish line are at least two receiving antennas, the signals from which are combined in opposite sense so as to form a difference signal. A system output signal then is produced which has a leading edge that occurs when the difference signal crosses zero. This output signal indicates that a competitor has passed the finish line.