| 摘要 |
PURPOSE:To eliminate the discontinuity of the phase of the carrier of an FM signal and to prevent the occurrence of an interference sound by changing-over the signals at the IF step, eliminating the influence of the characteristic difference at the detecting device and providing the signal of an intermediate phase of two FM waves on the way. CONSTITUTION:The output of amplitude limitting devices 9 and 10 is inputted to an intermediate phase generating part composed of a multiplier 15, a band pass filter 16 and a flip flop 17. The output of the amplitude limiting devices 9 and 10 and the intermediate phase generating part is respectively inputted to gain limitting devices 18, 20 and 19, gain controlling devices 18, 19 and 20 depend upon the output of a level deciding device 8, pass the FM wave only with a higher input level by a control signal generating device 21, the antenna with a higher input level is changed, the antenna are controlled so that the change-over can gradually executed. The click following the phase difference of an FM wave at the time of changing over the antenna is suppressed by shifting gradually an IF signal from one side receiving system to other side system with a gain control, and by providing the synthesizing signal of both systems in the middle of two FM waves, it is suppressed that the IF signal is denied. |
