Bought an HDTV receiver box today and TV modulator to feed vintage TV sets

[wa2ise]

Originally Posted by andy

Removing the chroma from a composite video signal is not at all easy. It's like unscrambling an egg. Even a sophisticated digital comb filter that compares several complete frames of video can't do it perfectly.

I used to do research and development at RCA Labs years ago on this problem. It is very hard to do it well. A reason that we get away with imperfect separation is that the portions of the luma image and of the chroma subcarrier (in terms of areas of the image on the CRT screen) track each other, and that our brains can pretty much ignore the crosstalk. Now if the two signals were unrelated, the crosstalk would be much more objectionable.