| 摘要 |
PURPOSE:To compensate sound transmission distortion due to ghost wave by transmitting a part of a sound subcarrier through a delay circuit and a phase shift circuit to form the wave into a signal having an opposite phase to that of the ghost wave. CONSTITUTION:A signal received by an antenna 1 is converted into a signal of an intermediate frequency band at a mixer 2, processed by a video system processing circuit 4 and a sound system processing circuit 5, frequency-converted by a mixer 6 and transmitted from an antenna 8. A part of the sound signal is extracted by a distributor 9 in this case to be formed into a sound signal having the same level as that of the ghost wave, the same delay time and of opposite phase by a variable delay circuit 10, a variable phase shift circuit 11 and a level adjusting circuit 12 and the signals are synthesized by a synthesizer 13. Then, the ghost wave is cancelled and the sound transmission distortion is compensated. |
