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Originally Posted by ceebee23
But on the other hand there would have been no phase error ..but then again extracting RBG would been fun ..and no saturation control....mmm...as for color fringing ...perhaps a quick check with the Early Television museum may clear that up ..as they have some CBS field sequential sets working????
Of course just as CBS did the blue banana trick RCA had swirling batons which very neatly showed this problem! ...aaaagh fun and joy
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Having no phase error was true IF the camera tube discharged completely on each field. So, image orthicons worked OK, but vidicon cameras using a color wheel would have contamination from one color into the next, requiring a complex apparatus to store frames if you wanted to fix it. (Or I suppose you could cheat and change the colors of the filters slightly.)
Also, the bit about no convergence errors is only true if the power supplies in the receiver are good. They must have good high voltage regulation so the raster doesn't change size between fields, even if the scene is mostly one color. My old boss who saw the original CBS tests talked about this problem in receiver design. Also, the power supply had to be low ripple, because the 60 Hz line was not in sync with the sweep. The monitors we saw at ETF last year seemed OK in this regard.