| 摘要 |
PURPOSE:To eliminate the effect on a mobile station on a main line due to the leakage of a transmission signal at test by using two waves of different frequencies for the transmission signal. CONSTITUTION:In measuring the transmission output, a test equipment 3 starts a radio equipment 7 through a control cable 11 and the output is measured by the test equipment through a signal cable 10 via a coaxial relay 12. In testing the modulation, a transmission relay a16 is closed and the signal is modulated by the 1st transmission signal 8 and the result is measured by the test equipment. Similarly, a transmission relay b17 is closed and the modulation is measured by the 2nd transmission signal 13. Since the modulation degree is measured one by one wave sequentially in this way, even when the transmission signal leaked from an antenna 6 reaches a mobile station on the main line, only one of transmission signal receivers 9, 14 is operative, and since no output of a coincidence circuit 15 is given, it is impossible to send stop information to the vehicle and the mobile station on the main line is operated according to the schedule. |
