Very, very early CoLoR TV

[Steve McVoy]

Username1, the problem with the mechanical (disk) system was picture quality. It was only 30 line resolution.

The Trinoscope was only to demonstrate color TV - RCA never considered selling it. At the time they were developing the tricolor tube, which they thought would be the solution.

There are several one gun color tubes, starting with a 1951 prototype:

http://www.earlytelevision.org/rca_d...al_onegun.html

Later attempts included the Philco Apple and Uniray:

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

[Electronic M]

IIRC Dumont made a tricolor tube with 3 separate guns. Each neck on the CRT was mounted separately on the bell 120 deg offset from the others (from the back the necks looked like a convergence yoke). the screen consisted of a pattern of triangular pyramids inside with each side having a different phosphor painted on so that only the gun that faced that side could scan it's phosphor. To me it looked less awkward than the triniscope and color wheels.

[Steve McVoy]

The Geer tube:

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

also Baird:

http://www.earlytelevision.org/baird...nic_color.html

[Carmine]

Originally Posted by Steve McVoy

The Geer tube:

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

That seems like a pretty good idea. I would think it would eliminate convergence issues (or perhaps create a whole new set of convergence issues). So each of these guns would require it's own yoke? Cost is probably why no one proceeded down that road.

This thread did remind me of a lot of great links I'd read years ago and probably forgotten about. It seems the RCA early color history is very well documented and known. I wish as much info was out there on early Zenith color work. I know they didn't offer a color set until '61-'62, but I recall reading they were the only manufacturer besides RCA that was capable of building their own color tube in 1953, so there was obviously research proceeding it.

[Electronic M]

IIRC Zenith invented electromagnetic dynamic convergence, and also had a rectangular 15GP22 based CRT on display in 1954.

[Steve McVoy]

Here is the CRT (21 inch):

http://www.earlytelevision.org/pdf/z...ngular_crt.pdf

[Robert Grant]

Originally Posted by David Roper

One or another division of RCA for sure. IIRC it was the very last triniscope made, so probably early 1950.

I thought I saw somewhere that a color set using the three-tube principle was actually put into production in Japan, circa 1963. I doubt they actually produced more than a few of them.

[Steve McVoy]

Mitsubishi

http://www.earlytelevision.org/mitsu...trinitron.html

[Sandy G]

Are there ANY survivors of the rectangular Zenith tubes left ? That anyone around here is aware of, anyway ?

[David Roper]

I think those were static displays. They were "shown" but they weren't demonstrated. IOW they didn't work.

[Sandy G]

SOMEWHERE, in the back of my Feeble Little Mind, I remember reading an article in the mid-late Seventies in "Popular Science/Popular Mechanics", one of those mags, of a "Big Development" in color TV that had been undiscovered since its development in the Fifties... There were pics of the display, & the CRT had the familiar "ALMOST Round" shape of Mid-Fifties CRTs. This ringing a bell w/anybody ?

[zeno]

Originally Posted by Steve McVoy

Mitsubishi

http://www.earlytelevision.org/mitsu...trinitron.html

That MGA set is strange. All US tube numbers & a series string. Only
the damper uses a jap number. The yokes look US but everything
else Japan. The 5GH8's bring back not so fond memories of the
first plastic RCA 19" sets.
Gotta be a joint effort US-JP maybe RCA involved ???

73 Zeno

[old_tv_nut]

Originally Posted by Sandy G

SOMEWHERE, in the back of my Feeble Little Mind, I remember reading an article in the mid-late Seventies in "Popular Science/Popular Mechanics", one of those mags, of a "Big Development" in color TV that had been undiscovered since its development in the Fifties... There were pics of the display, & the CRT had the familiar "ALMOST Round" shape of Mid-Fifties CRTs. This ringing a bell w/anybody ?

This rang no bells with me, but a search on the earlier Philco "Apple" beam index tube turned up this article posted at earlytelevision.org:

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

Is this it?

[old_tv_nut]

Here it is on cover of Feb 1972 Pop Sci

http://books.google.com/books?id=Ixq...page&q&f=false

[Steve McVoy]

A couple of years ago we were contacted by the family of the guy who developed the Uniray. They said they had his prototype set and tube. They paid to have it shipped to Hilliard, and we waited excitedly. When the box arrived it contained a CTC-7.

The family spent some time trying to find where the Uniray set was, but never found it.