I just watched the very impressive member Steve McVoy...

[JB5pro]

on the History Channel. During the part where he shows and discusses the mechanical color TV the narrator said that the picture was much better than the first electronic color TV in '54.
That does not make sense to me as the '54 Color TV's had beautiful pictures as enjoyable as today's picture with some convergence flaws on outer edge of picture. Am I wrong? I thought I learned that from what I read here?
Did the History Channel make a mistake? Was the mechanical color picture really better than electronic?
Thanks,
John

[jstout66]

Hey John,
I've seen one in operation, and yes, in my opinion, the picture was better.

[David Roper]

Are we talking about CBS color? It's not quite fair or accurate to call it a mechanical system just because the only practical way to display it in '51 was by mechanical means. There would have been tri-color CRT sets for CBS color if the system hadn't been abandoned. As for its superiority, at the time of its approval it was the only system that truly worked, RCA having laid a colored egg (to quote Variety) in demonstrations before the FCC.

Its shortcomings were incompatibility with the black and white standard, relatively poor resolution and flicker. But the simplicity of CBS color wheel sets work in the system's favor. At the 2004 ETF Convention when CBS color was on display for the first time in over 50 years, there was almost unanimous agreement that the CBS color wheel sets out performed a 15GP22 NTSC set in side-by-side comparisons.

[Aussie Bloke]

This is an interesting thread. Has got me thinking and I have a question. Is the superiority of the CBS colour wheel set over the NTSC 15GP22 tube colour TV got anything to do with the fact the 15GP22 and all other colour CRT sets having a shadow mask in which in close range the phosphor dots are seen unlike on the colour wheel set as the B&W tubes have no shadow masks?

[Phil Nelson]

TV shows have been known to over-simplify

The ETF website has loads of information about early color, and that's a great place to learn more:

http://www.earlytelevision.org/color.html

At yesterday's ETF convention, you could see both types of early color TV -- color-wheel and all-electronic -- operating in the same room. Just for fun, I took some snapshots of each example. Without getting into fine points, which experts can discuss for hours, there's no doubt the average person could look at either type of TV and say, "Hey, nice color."

These photos were taken without a tripod while a DVD was playing (i.e., not paused), so all of the screens are somewhat blurry. This is not a lab setting, so don't judge the color by my terrible camera, which auto-adjusts everything in several bad ways.

Of course, the DVD was produced with the NTSC standard, not the CBS color standard, so all that the photos really prove is that either kind of TV can display an enjoyable color picture.

The color wheels were operating in front of ordinary 10" black and white TVs of the day. The smaller CBS color wheel uses a magnifying lens and requires a separate electronic box not shown in the photo.

CBS Color Converter:


Col-R-Tel kit wheel:


RCA CT-100 all-electronic TV (with newly rebuilt 15GP22 CRT):


Any scheme with a color wheel had obvious scalability problems. Look at the size of the Col-R-Tel wheel for a 10" TV. Scaled up for a 21" TV, it would reach the ceiling.

The CT-100 had been hastily set up to demonstrate a freshly rebuilt 15GP22 CRT that arrived from France via air freight at the last minute. It has more convergence and purity issues than a fully dialed-in CT-100.

I think the deal-breaker for the CBS system was lack of compatibility with existing black and white broadcasts. Tens of millions of black and white TVs had been sold. Owners of color sets could not watch any black and white programs. Owners of black and white TVs could not see any programs broadcast in color. Consider today's satellite radio, another commercial flop.

And look how far we've come! Here are two photos from the flat screen TV in my Columbus hotel room.

Game show:


Local digital broadcast breaking up during rain shower:


Phil Nelson

[yagosaga]

Breathless stunning!

[tubesrule]

It's a compliment to the CBS sets at the museum to compare them favorably, and in some cases superior to the 15GP22 sets. Keep in mind though that the 15GP22 and CT100 weren't used during the FCC color trials in 1950/51. The state of the art of RCA color television in 1950 was far from the CT100, so it's easy to understand how CBS won out.

The compatibility issue was a factor but was somewhat overstated by RCA. CBS color sets were designed to receive both standard B&W broadcasts and CBS color broadcasts. CBS also published required modifications for most common sets like the RCA 630 to receive both standard B&W and CBS color broadcasts. (the latter in B&W only of course)

Also while a color wheel would be unwieldy for larger sets, CBS demonstrated drum scanner sets which were much more compact, and when the shadow mask tube was finally perfected, it could have been used just as easily with the CBS system.
These CBS sets are still amazing to watch!

Darryl