| 摘要 |
PURPOSE:To simplify the circuit constitution by providing an all-band tuner and a BS tuner in common and using a high frequency amplifier circuit, a local oscillation circuit and a frequency conversion circuit to both tuners in common. CONSTITUTION:A 1st intermediate frequency signal AIF1 for the all-band tuner or a 2nd intermediate frequency signal BIF2 for the BS tuner are outputted by applying frequency conversion to a signal ARF or BIF1 from a high frequency amplifier circuit 31 based on a local oscillation circuit LO to be changed over by means of a frequency conversion circuit 32. Then a changeover circuit 36 throws an output section of the frequency conversion circuit 32 to the position of the 1st intermediate frequency filter 14 side in the case of the all-band broadcast and to the position of the 2nd intermediate frequency filter 24 in the case of the satellite broadcast. Thus, the television tuner is switched into the all-band tuner aud the BS tuner.
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