Early color TV in Italy

[old_tv_nut]

Originally Posted by ceebee23

NTSC is not capable of producing a true RGB signal ...because of the weighting of the I and Q signals but both PAL and SECAM contain the full RGB components BUT of course an NTSC style system for 625/25 could be set up to provide true RGB

I don't understand this statement at all. I and Q have nothing to do with the correctness of the RGB components. In fact, PAL and SECAM use exactly the same electrical matrix as NTSC - they just modulate the chroma on equal-bandwidth (R-Y) and (B-Y) wothout going to the intermediate non-equal bandwidth I and Q. However, in PAL and SECAM cameras, BEFORE the chroma components are matrixed, modern cameras do have a matrix to form the correct RGB values for the modern phosphors in current picture tubes. NTSC cameras hypothetically have a different matrix to match the original NTSC phosphors, while NTSC receivers are often designed with an (approximate) matrix for modern phosphors that works on the chroma signal only. In practice, modern cameras for NTSC have a matrix that is modified to get pleasing pictures on current studio monitors. This confused situation of some correction at the studio and some in the receiver has never been completely corrected for NTSC, but has been correcterd for high-definition TV.

None of the above has anything at all to do with I/Q modulation.

Originally Posted by ceebee23

In fact NTSC has superior transmission characteristics for long distance cable/microwave transmission than either SECAM or PAL.

That's an interesting statement. In what way is NTSC superior for long distance cable and microwave? I would think PAL to be superior due to the phase distortions that could accumulate in multiple-stage video links.