| 摘要 |
PURPOSE:To improve the operability by adjusting the direction of an FPU reception antenna while listening to a call tone from a speaker in place of the indication of a meter. CONSTITUTION:A microwave 101 from a mobile relay car 2 is received by an antenna 3 of an FPU reception base and its FPU reception electric field 102 is detected by a receiver 4 and inputted to a controlled terminal station section 5 as a BL radio wave 103 and transmitted to a control terminal station section 6 at a studio by means of telemetering via a supervisory line 104. A DC voltage equivalent to the level of the received electric field strength 102 is regenerated at the section 6, indicated on a meter 10 and also converted into an AC signal of an audible frequency band by a VFO circuit 7 and then sounded by a speaker 9 as a call tone. Thus, the direction of the antenna 3 is adjusted so that the tone frequency is maximized or minimized while listening to the call tone. |
