| 摘要 |
PURPOSE:To improve the effective reception sensitivity to prevent the occurrence of inter-modulation distortion by providing a high frequency signal processing part attached to an antenna mast and an optical fiber and transmitting the tracking signal sent from a channel selecting means of a receiver body to the high frequency signal processing part and the detection signal sent from the high frequency processing part to a low frequency amplifier as optical signals. CONSTITUTION:A receiver body 30 is provided with a channel selecting means 31, a low frequency amplifying circuit 32, a light emitter 33, and a light receiver 34. The channel selecting means 31 adjusts a DC voltage and outputs it to a turning type amplifier 21 of a high frequency signal processing part 20 as the tracking signal. Since the frequency band tuned to a prescribed frequency band is narrower, cross modulation is difficult to occur. Consequently, inter- modulation distortion is small even if the reception level of an objective channel is low and that of a disturbing channel is high. Since the detection output is converted to an optical signal and is transmitted to the receiver body 30, the degradation in tone quality due to noise mixture does not occur. Since the tracking signal is converted to a light and is transmitted, the malfunction of channel selection due to electromagnetic noise is reduced. |
