| 摘要 |
PURPOSE:To suppress the disturbance due to direct mixing of an FM sound signal and a pilot signal, and the beat disturbance produced by the nonlinearity of a tape and a head system, by emphasizing a mainly side band energy of a chrominance signal dunamically at recording and deemphasizing it dynamically at reproduction inversely. CONSTITUTION:An output signal of an ACC amplifier 4 is connected to an emphasis circuit 35 via a switch 30, a burst emphasis circuit 5, and a switch 52 at the recording and the result is connected from a terminal 102 to a converter circuit. Switches 28, 30, 52 are changed over to opposite positions from those shown in a figure at the reproduction, and an output signal of the ACC amplifier 4 is connected to the emphasis circuit 35 via the switch 30, a comb line filter 16, a differential amplifier 300 and the switch 52 and its output is fed back negatively from the terminal 102 to a terminal of the differential amplifier 300. The output signal is extracted from an output of the differential amplifier 300 to a burst deemphasis circuit 17. Since trap circuits 214, 213 are used in common for the recording/reproduction, the dispersion in the frequency characteristic is reduced. |
