| 摘要 |
PURPOSE:To extract only desired sound intermediate frequency signal and to improve the SN ratio by providing the first and the second filters for extracting the first and the second sound intermediate frequency signals and preventing the passage of an input or an output to the second filter when the first sound intermediate frequency signal is extracted. CONSTITUTION:When it is attempted to obtain the sound intermediate frequency signal by any band of 6.5MHz, 6.0MHz, 5.5MHz, a signal of H level is supplied to a control terminal 13. A chroma carrier present in an IF signal is checked by a transistor 12 and not outputted from a ceramic filter 9. When it is attempted to obtain the sound intermediate frequency signal of 4.5MHz band, a signal of L level is supplied to the input terminal 13. Thereby, the sound intermediate frequency signal of the 4.5MHz band is taken out from an output terminal 10 by passing through the ceramic filter 9 without being blocked by a block circuit 11.
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