[Dave A]

To save some search time...the Indextron tube is a straight-line stripe from top to bottom with a black guard band in-between each stripe. No shadow mask or wire mask. Just a RGB switched color beam going to it's matching color stripe.

Black/Red/Black/Blue/Black/Green and so on. It knows where it is by sensing the green stripe from the rear of the tube. Thus the indexing. This set actually has a few stripes ahead of the viewing area to get it up to speed and keep it synchronized.

See Chuck A's site for the history of this concept in the Philco Apple tube. Sony ended up with the rights to the concept and this is what they did.

It ain't Linytron or Trinitron.

The black guard band prevents the previous switched color beam from contaminating the next color stripe during the color switch in the guard band. And focus is critical. If the beam spot focus is too big, it leaks across the guard band and contaminates the next stripe before the switch. Red beam in to green stripe, etc. It looks just like a degaussing problem.

If you count the guard band as a pixel, you have a six-wide pixel with no next line stagger for the traditional triad. Double the normal triad RGB pixels and now half the resolution with the color stripes easily visible.

And now that you have a black guard band after every RGB stripe, you have 1/2 of your screen in black. That is assuming that the guard band is as wide as the color stripe. I suspect smaller but that does nothing for brightness and contrast.

All said, I cannot think of any variation of analog tv like this that actually worked other than color wheels. Therein lies the rarity and collectability.

And my Indextron, restored by Andy, will be the set I watch the sunset of analog on.

Dave A