GROUP DELAY PRE-CORRECTION

The specifications for a number of television systems state that the transmitted signal must be pre-corrected in terms of group delay pre-correction  to allow for the distortion produced by the IF filters in television receivers.

CCIR Rep.624 recommends three curves which apply variously to the following systems: B/PAL,G/PAL, M/PAL and M/NTSC.

The response of the three networks offered correspond to the three recommended curves in terms of group delay and are equalised to have an amplitude ripple of less than 0.2 dB over the video band. They are supplied in 40 pin encapsulated modules which occupy a board area of less than 11 sq. cm.