Why did others drop out of early color manufacturing?

[David Roper]

Umm, that's three dead links in this thread now.

[G.B.]

OK, I don't get it but when you click this , & remove the - 2 & hit enter you get the picture ? Shows all Color TV for 1957.......Lets try one more time ? http://community-2.webtv.net/stevete.../importD10.jpg

[Steve D.]

Originally Posted by G.B.

OK, I don't get it but when you click this , & remove the - 2 & hit enter you get the picture ? Shows all Color TV for 1957.......Lets try one more time ? http://community-2.webtv.net/stevete.../importD10.jpg

Don't know what the problem is? I can access the url without any problem. Thanks Chad for posting the thumbnail.

-Steve D.

[G.B.]

T D Ryan I don't ge this. If you put this up & it says it is a dead link. But if you remove the -2 you get the picture you try it Please. Then when you post you get this & it will not open...

[Chad Hauris]

Here it is, I right clicked and saved it:

[G.B.]

Thanks Chad for your help & SteveD. for the history. May be the server of the forum or something. chad did you get my email ? Sent you personal on forum & to your Retro Audio Lab....

[bgadow]

I have the book shown, but thats not the one I was referring to. I saw it in a bookstore somewhere, it was published in the last decade, I think. Had pages of sets-some may have been of the CBS color-wheel variety. All were small screen from c.1954. I seem to recall sets from companies like Andrea, Stromberg-Carlson, etc. These appeared to be new photos, taken of sets in somebodies collections. I only saw that book once; it was too expensive for me to buy it at that time.

[Don Lindsly]

Several factors slowed rectangular color tubes.
1. Availability of blanks from Corning
2. Consistency in corner convergence
3. Shutting down round tube production to make way for rectangular tube capacity
4. Availability of thin CRT guns
5. Availability of yokes, flybacks and other components, in production quantity, to support the new format
6. Reluctance of other manufacturers to commit too soon
7. Heat problems in the thin neck. That's one reason most rectangulat tubes run on lower heater current.
8. Getting the service industry up to speed
9. Why push it prematurely if round tube color sets were selling well? Wait until it's ready. The manufacturers did not want to repeat the first generation mistakes that were still fresh in the serviceman's and customer's minds.
10. Don't forget that most round tube sets looked pretty good 35-45 years ago. They were relatively new, had good bright CRTs and nice pictures. Greed was not the prime factor. It was what the public would accept.

Don

[old_tv_nut]

Cutting off the top and bottom probably made convergence easier, but I think it was mainly that porthole designs were long dead, and black and white sets had already gone from cut-off to rectangular - so going to flat top and bottom was only one stylistic step backwards. The RCA 15 inch tube had an internal bezel defining this shape. Thsi disappeared when tube construction was simplified for the 21-inch, but the external bezel was cutoff the same way.

[G.B.]

Old TV Nut, That's was what I had heard as well. What folks don't understand now was the fact that it was true color & most was ready to watch any shape screen in the early day's....

[frenchy]

What is the difference in total square inches of viewable screen area between a masked 21 inch round and 23 inch or 25 inch rectangular anyway? Since 25 was the biggest size for a looooong time maybe there wasn't that big of an advantage for rectangulars screen-size wise over roundies anyway - mainly it just got rid of the 'round' part.

[andy]

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[Chad Hauris]

A round color tube is a "19V" tube, it has a 19 inch diagonal viewable area. (some of the very late model round tubes are labeled with a 19V" designation)
This is theoretically the same viewable area as on say a 19" Zenith solid state Chromacolor set using a 19V" rectangular tube.

[Whirled One]

Originally Posted by Chad Hauris

A round color tube is a "19V" tube, it has a 19 inch diagonal viewable area. (some of the very late model round tubes are labeled with a 19V" designation)
This is theoretically the same viewable area as on say a 19" Zenith solid state Chromacolor set using a 19V" rectangular tube.

Uh, but the "19V" only refers to the diagonal of the viewable phosphor area on the front of the tube. It has nothing whatsoever to do with viewable area of the tube, or, for that matter, the typical image size shown on the screen. These are all entirely different geometric measurements, and it's easy to demonstrate the lack of relationship between them. There seems to be some confusion here in this thread.

For example, in my living room I have an old 21" roundie (19"-viewable) color and a modern 27"-viewable square-cornered rectangular set. The 27" set of course produces a rectangular picture. The roundie has the typical pumpkin-shaped mask of its ken. If I measure the height of the mask on the roundie, I see that the picture it produces is almost exactly 16 inches in height. Now I make the same measurement on the 27" set. It too produces a picture almost exactly 16 inches in height! Since both are NTSC sets, the images they produce (including non-visible areas) will have the same height/width ratio. Therefore, if both TV sets were adjusted so that the raster perfectly fit that 16 inches of visible height, and were tuned to the same program material, objects shown on both sets would appear exactly the same size. It doesn't matter that the "roundie" has a much smaller diagonal than the 27" rectangular set. The face of the 27" set also has a significantly larger viewable area as well. However, the *size* of the images they show is the same. It's just that the roundie cuts off the corners (as well as parts of the sides), so it displays a less *complete* picture, but it's the same *size*.

Here's another quick experiment which demonstrates the opposite comparison. Take a look at the attached picture. Using a paint program, I've drawn two circles of the same size, labeled A and B. Keep in mind that the "diagonal" of a circle is the same as its diameter. On circle A, I've drawn a 4:3 ratio rectangle in which the width fits just a bit outside the circle. On circle B, I've drawn a 4:3 ratio rectangle that fits just inside the circle. Obviously, rectangle A is much larger than rectangle B. If you were to measure the area of the intersections of the circles and rectangles, you'd still find rectangle A to be larger, though not nearly as much larger as the height/width of the rectangles would suggest. So, it's easy to see that a "19V" roundie (when masked to a 'pumpkin' shape) will produce images that are both larger in height/width as well as square area compared with the "19V" rectangular tube, despite the fact that both have the same viewable diagonal dimension.
[NOTES: These are "theoretical" diagrams for illustrative purposes. In reality, most color roundie sets are maksed such that the usable height of the image is maximized a bit (to get a larger image size) at the expense of width-- note that with a 16 inch picture height, the 19:16 resulting image ratio doesn't match the 4:3 ideal. So "roundie" sets usually actually cut off parts of the sides as well as the corners. Also, most 19" rectangular sets are actually rounded-off rectangles and as such have a somewhat larger image size than the CRT face would indicate; i.e. the rectangle would actually extend beyond the circle a bit if I were to really draw it like rectangle B.]

Okay, I think that's enough geometry for today.

[andy]

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