Another RCA CT-100 discovery B8001599

[Penthode]

I am impressed with the H840CK15. It has 4 IF stages and appears to demodulate the chroma on the R-Y and B-Y axes. This means early on it appeared to be the sensible way forward.

However I question the written statement that the placement of the color subcarrier at the 50% point is on the curve depicted.

Although it is stated that the the color subcarrier (42.17MHz) is at the 50% point on the curve, it looks to me 42.17MHz is at the 100% point. Perhaps teh 50% is instead 41.70MHz?

[nasadowsk]

Originally Posted by Penthode

I am impressed with the H840CK15. It has 4 IF stages and appears to demodulate the chroma on the R-Y and B-Y axes. This means early on it appeared to be the sensible way forward.

RCA seemed to flop around for a while, trying different schemes. But they settled on R-Y and B-Y, with the CTC-7. I wonder what took them so long, and I wonder if it was more political than technical? After all, RCA was famous for not wanting to be a licensee, and”borrowing” a Westinghouse patent was a no-go. Thus the 4 and 5 were a bit… experimental. Maybe by tge time the 7 came around, they were desperate to get color moving, and gave in?

Also, didn’t Zenith come up with the convergence scheme that ultimately got used by everyone?

(Also, my 4 notes that it uses patens from Phillips. I don’t know what that is about)