| 摘要 |
A TV tuner is provided to input and synchronize a signal in a VHF low band through a switching unit when selecting the VHF low band and trap a signal around a 6channel band in the VHF low band by operating a 6channel beat trap unit when selecting the 6channel band by composing the switching unit and the 6channel beat trap unit in the front end of a VHF low band input sync circuit, thereby preventing a 6channel beat. A TV tuner includes an HPF(High Pass Filter)(20), an IFT(Intermediate Frequency Trap)(21), a CBT(Citizen Band Trap)(22), an UHF(Ultra High Frequency) input sync circuit(23), a VHF(Very High Frequency) high band input sync circuit(24), a VHF low band input sync circuit(25), a 6channel beat trap unit(27) and a switching unit(26). The HPF passes a high frequency signal more than a predetermined level in a high frequency signal inputted from an antenna. The IFT traps an IF(Intermediate Frequency) signal radiated to the outside in the high frequency signal passing the HPF. The CBT traps a citizen band. The UHF input sync circuit inputs and synchronizes the high frequency signal outputted from the CBT into an UHF band of 470 to 850MHz. The VHF high band input sync circuit inputs and synchronizes the high frequency signal outputted from the CBT into an UHF band of 150 to 470 MHz. The VHF low band input sync circuit inputs and synchronizes the high frequency signal outputted from the CBT into an UHF band of 50 to 150MHz. The 6channel beat trap unit traps a 6channel beat. The switching unit outputs the high frequency signal outputted from the CBT to the VHF low band input sync circuit through the 6channel beat trap unit.
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