| 摘要 |
Samples of the amplitude of a quadrature amplitude modulated (QAM) subcarrier signal are taken at times corresponding to each axis crossing of each of the two quadrature related signal components. The polarity of alternate ones of the samples is inverted and the signal is reconstructed from the inverted and non-inverted samples whereby the phase of one of the signal components is reversed without alteration of the phase of the other. Where the QAM signal is a television chrominance signal, means are provided for periodically inhibiting inversion of the samples on alternate lines whereby PAL type chrominance signals may be converted to or from NTSC or NTSC "like" chrominance signals.
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