WIRETAP PREVENTING CIRCUIT OF RADIO TELEPHONE SET

摘要

PURPOSE:To prevent perfectly the wiretap of a radio telephone set by actuating the telephone after setting a comparator in a waiting mode with two pilot signals. CONSTITUTION:A pilot signal oscillator 9 is provided to a slave device (a) to oscillate successively two pilot signals; while a pilot signal comparator 16 is provided to a master device (b) respectively. The comparator 16 is set in a waiting mode with the first pilot signal actuated with the next pilot signal. A telephone circuit closing circuit 18 is actuated by the output signal of the comparator 16 to close a telephone circuit. Thus the tapwire preventing effect is improved by increasing the combination of two pilot signals.