| 摘要 |
PURPOSE:To judge and display that received broadcasting is high-vision broadcasting by means of a simple circuit at the time of receiving high-vision broadcasting through an NTSC satellite broadcasting receiving equipment. CONSTITUTION:An AGC voltage formed by an FM demodulating circuit 3 and fed back to a BS tuner 2 is compared with a prescribed reference voltage by a comparator 21. The NTSC satellite broadcasting receiving equipment judges and displays the reception of high-vision broadcasting by means of a logical circuit 22 for obtaining AND operation between the output of the comparator 21 and a frame synchronizing error signal detected at the time other than the reception of NTSC satellite broadcasting outputted from a PCM decoder 8 in a BS sound demodulation signal processing part and a display circuit 23 consisting of high-vision display in accordance with the output of the logical circuit 22.
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