| 摘要 |
PURPOSE:To improve the reception sensitively by designing the titled equipment so that the setting of the maximum frequency deviation in a transmission circuit is switched in response to a reception electric field strength and also the pass band of a pass band filter in the reception circuit is switched interlockingly. CONSTITUTION:A switching circuit 6 to change the maximum frequency deviation and a tone generator 5 to superimpose the tone in response to the switching state are provided to the transmission circuit respectively and the other constitution is the same as that of a conventional equipment. Further, the reception circuit is provided with wide/narrow band pass filters 16, 27 switched interlockingly with the switching of the maximum frequency deviation of a transmission signal simultaneously and a switching circuit 24 to switch them. Moreover, a comparator 21 discriminating the switching to the setting value of the reception electric field level after the demodulation to control the switching circuit 24 and the band pass filter 25 to detect the presence of a tone signal when the reception electric field level reaches the setting value are provided, and even when the reception electric field does not reach the setting value at its own station side, the maximum frequency deviation of the transmission circuit and the band of the reception circuit are switched interlockingly.
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