| 摘要 |
PURPOSE:To compensate the time axis fluctuation of a recording signal due to unevenness of rotation of a head, by detecting a rotating frequency of the rotary head and using this detecting signal as a carrier signal in forming a low converting chrominance signal. CONSTITUTION:A recording signal appearing at an output terminal 22 of a recording amplifier 21 is applied to rotary heads 23A, 23B and recorded on a magnetic tape 25. A magnetic disc 28 is fixed to a drum rotary shaft 26 of the rotary head and a magnetism sensor 29 is provided near the disc 28. A detecting signal from the sensor 29 is applied to PLL circuits 31, 32 via a waveform shaping amplifier 30. The PLL circuit 31 generates a sub-carrier signal, which is applied to balancing modulation circuit 3, 4, the PLL circuit 32 generates the carrier signal having, e.g., 175fH/4 (fH: horizontal scanning frequency) of low converting frequency, and the signal is applied to a circuit 8 converting the chroma signal into the converted chroma signal of the low carrier frequency via a switch circuit 33. |
