|
With the Indextron, (or the early "Apple" tube) you should get no convergence error, because there is only one beam emanating from a constant position. The RCA tube, however, moves the apparent point of emission, so its beam is going through a different part of the deflection yoke aperture depending on the color selected. In this case, all bets are off. You have essentially turned one beam into three sequentially. You need specifically to design so the beam hits the same spot on the screen no matter what the color-selection field is doing.
By the way, even a field-sequential set can show "convergence" errors if the high voltage and sweep are not perfectly stable from field to field. We could see this on the "personal viewer" color wheel at ETF when the contrast was turned up too high on the DuMont set, causing alternate fields to have different scan widths.
|