| 摘要 |
PURPOSE:To respectively obtain an optimum characteristic with EP and SP modes and to improve a picture quality by constituting the titled equalizer so as to switch the characteristic of an FM equalizer. CONSTITUTION:The characteristic of an FM equalizer is determined by the general characteristic of a peaking circuit 1, a phase shifting circuit 3, and a chromatrap 4. At the time of an EP mode, transistors TR1 and TR2 are turned off, and at the time of an SP mode, they are turned on, the Q value of the peaking circuit 1 is changed, and in accordance with it, a frequency characteristic and a phase characteristic are also changed. The characteristic of the phase shifting circuit 3 is also changed in the same way. At this time, respective constants are set so as to be respectively the optimum picture quality with both modes of EP and SP. Consequently, since a frequency characteristic is set in accordance with the modes of SP and EP, the characteristic optimum to respective modes is obtained and the picture quality is improved.
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