| 摘要 |
PURPOSE:To perform automatically the inspection work for a multiple radio loud speaker receving station, by providing a transmitter, which transmits an inspection command signal, in the inspecting device and by tramsitting a prescribed signal with acoustic waves of an inaudible frequency from the receiving station when the receiving station detects the inspection command signal. CONSTITUTION:In case of inspection for a receiving station, an automatic inspecting device is brought near the receiving station, and a transmitter 21 is modulated by an inspection command signal generated from a signal generator 22, and radio waves of the same frequency as the receiving frequency of a receiver 11 are transmitted with a weak power for a short time. These radio waves are demodulated by the receiver 11 and are inputted to a switching circuit 12 and a decoder 13; and when the inspection command signal is detected by the decoder 13, the output of the circuit 12 is cut off, and coder 16 is started. The coder 16 controls the oscillation of the inaudible frequency of an oscillator 17 by coded inspection item information in the receiving station and amplifiers the inaudible frequency in 14 to transmit a code due to acoustic waves of the inaudible frequency from a speaker 15. These acoustic waves are received by a microphone 23 and are decoded to original information by a decoder 24 and are recorded on a recorder 25. |
