在PAL_D彩色电视接收机中,有一个由超声延迟线组成的梳状滤波器,它使色度信号的两个分量在同步检波之前先分离开,因而克服了NTSC制的相位敏感性.通常,PAL延迟线的参数用延迟时间63.943微秒来标志.对此,国外有关文献认为,PAL制存在着延迟时间与行周期(64微秒)间有57毫微秒误差的缺 In the PAL_D color television receiver, there is a comb filter consisting of an ultrasonic delay line which separates the two components of the chrominance signal before the synchronous detection, thus overcoming the phase sensitivity of the NTSC system.Usually, PAL delay line parameters with a delay of 63.943 microseconds to mark this regard, the relevant literature that the PAL system there is a delay between the delay and the line cycle (64 microseconds) 57 nanoseconds between the lack of error