| 摘要 |
The invention relates to a television signal receiver comprising a radio-frequency tuner ( 1 ) and at least one subsequent surface-acoustic wave filter ( 2 ), in which the radio-frequency tuner ( 1 ) filters a RF television signal applied to its input and converts it to an intermediate-frequency television signal which is coupled to the surface-acoustic wave filter ( 2 ). The RF tuner ( 1 ) has at least one output stage ( 16 ) which supplies the IF television signal converted to the intermediate frequency. The output stage ( 16 ) is directly connected to an output ( 6 ) of the RF tuner ( 1 ), while a switch ( 10 ) is associated with it, by means of which switch the IF television signal is supplied to a second output ( 8 ). A further switch ( 11 ) is associated with the second output ( 8 ), by means of which switch the associated output ( 8 ) is switchable to a fixed reference potential. The RF tuner ( 1 ) precedes at least one surface-acoustic wave filter ( 2 ), in which each time a first input ( 12 ) of the surface-acoustic wave filter ( 2 ) is coupled to a first output ( 6 ) of the RF tuner ( 1 ), and a second input ( 13 ) of the surface-acoustic wave filter ( 2 ) is coupled to the second output ( 8 ) of the RF tuner ( 1 ) via the first switch ( 10 ), and, for switching the filter characteristic of the television signal receiver, alternately the second input ( 13 ) of the surface-acoustic wave filter ( 2 ) can be coupled to the same IF television signal by means of the associated switch ( 10 ).
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