PURPOSE: To remove the image frequency of a VHF high band by allowing an HPF constituting a UHF branching circuit to operate as a trapping circuit for the image frequency band in the VHF high band in the case of receiving the VHF. CONSTITUTION: When a tuner receives VHF, a high frequency amplifying transistor(TR) TR 2 in a UHF part is turned off and the serial circuit of a capacitor C 4 ' to be a part of the HPF constituting the UHF branching circuit and a coil L 4 ' is connected between an antenna input terminal T and the earth. The values of the coil L 4 ' and the capacitor C 4 ' are set up so that the circuit 6 acts as a serial resonance trapping circuit for the image frequency of the VHF high band. Thus, the image frequency of the VHF high band can be removed. COPYRIGHT: (C)1988,JPO&Japio




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Patent Citations (2)

    Publication numberPublication dateAssigneeTitle
    JP-S5218010-UFebruary 08, 1977
    JP-S6120170-AJanuary 28, 1986Nec CorpInformation processing system

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Cited By (1)

    Publication numberPublication dateAssigneeTitle
    JP-2007142838-AJune 07, 2007Sharp Corp, シャープ株式会社Electronic tuner