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-   -   21” RCA Color in 1951 (http://www.videokarma.org/showthread.php?t=273963)

John Adams 04-30-2021 03:47 PM

21” RCA Color in 1951
 
While reading old issues of Radio and Television Retailing on line, the November 1951 issue shows a picture of a experimental 21” color console being shown to the industry. Several months prior, they had a picture and cutaway of a 16 and 21” Tri-color tube. I assume they were referencing the 15” instead of a 16 inch tube. I am curious as to why they did not just jump in with the 21” tube to start with.

Penthode 05-28-2021 11:28 PM

Where is the link to the article?

reeferman 05-29-2021 08:23 AM

If the industry could have started with a 21" CRT, believe me, they would have started with a 21" CRT.
Here's a link to RCA's color TV proposal to the FCC.

https://worldradiohistory.com/Archiv...posal-1953.pdf

Tricolor kinescopes and associated components start on page 263
Tricolor kinescope demonstration in March/April '50 on page 277
Envelope sized pages 296, 297, 322
Receivers for the RCA color TV system page 306.

I have no idea if this will help you or not.

rld-tv01 05-29-2021 10:26 AM

I think this is the link referred to:
https://worldradiohistory.com/Archiv...ng-1951-11.pdf

Page 84 bottom left "Viewing RCA Color TV"

etype2 05-29-2021 05:47 PM

Date of publication, November, 1951. Photo probably shot in October, 1951. From the link provided above.

https://visions4netjournal.com/wp-co...CA36D2D39.jpeg

etype2 06-02-2021 08:02 PM

Another RCA 21 inch color prototype.

https://visions4netjournal.com/wp-co...CA841FB56.jpeg

Electronic M 06-02-2021 09:51 PM

The grille bars and cabinet look similar enough in that bigfoot-sighting-resolution news print to the image you posted that it might be the same set...

Quote:

Originally Posted by etype2 (Post 3234341)
Another RCA 21 inch color prototype.

https://visions4netjournal.com/wp-co...CA841FB56.jpeg


Tom9589 06-03-2021 12:43 PM

The front panel knob configuration looks like the same configuration as the 16 " Tricolor Kinescope receivers 1 and 2.

It could be a mock-up, too. (Photoshop wasn't around back then)

jhalphen 06-03-2021 01:46 PM

Hi to all,

I am very skeptic about an RCA working color CRT in 1951.
For the following reasons :

- Making the 12" 15GP22 was absolute hell : a suspended flat color phosphor plate which frequently cracked during high-temp processing.

- The phosphor plate was produced by silkscreen printing : poor precision and lots of rejects. Much more difficult with 21" than 12".

- The CBS rear-of-screen phosphor deposition process via a lighthouse hadn't been invented yet.

Maybe they made ONE that worked just for the IRE photo...

Best Regards
jhalphen
Paris/France

reeferman 06-03-2021 09:55 PM

A working 21" color prototype in 1951?
I'm like Kojak.
I don't buy it.
I have never seen any proof.
The following is from the late Ed Reitan's website.

"July 9, 1951. A 21-inch direct-view color picture tube was shown by RCA. (RCA used the term "shown" when equipment was not operational!)"

http://www.earlytelevision.org/Reita...bc_firsts.html

John Adams 06-05-2021 05:05 PM

Quote:

Originally Posted by reeferman (Post 3234376)
A working 21" color prototype in 1951?
I'm like Kojak.
I don't buy it.
I have never seen any proof.
The following is from the late Ed Reitan's website.

"July 9, 1951. A 21-inch direct-view color picture tube was shown by RCA. (RCA used the term "shown" when equipment was not operational!)"

http://www.earlytelevision.org/Reita...bc_firsts.html

That makes sense. Appears that several proposed tubes never made it to production. Several CRT manufacturers used terms like "samples" which were furnished to manufacturers prior to production.

Electronic M 06-05-2021 07:59 PM

There were working Apple Chromatron CRTs demonstrated in the 50s, but they never could figure out how to to manufacture them with acceptible yield. Even Sony who actually mass produced that design prior to arriving at the Trinitron, had yield that was close to 50% defective.

It's not implausible that at the same time the 15GP22 was being developed there was a 21" CRT in the works, but it had a worse yield and didn't get produced. RCA spent $6M in 50's money to develop the 15G and other companies like CBS made it woefully obsolete in a few months of production...I'm not sure if you would call that world leading development or getting a workable solution through brute economic force.

etype2 06-05-2021 09:10 PM

Quote:

Originally Posted by Electronic M (Post 3234411)
There were working Apple Chromatron CRTs demonstrated in the 50s, but they never could figure out how to to manufacture them with acceptible yield. Even Sony who actually mass produced that design prior to arriving at the Trinitron, had yield that was close to 50% detective.

It's not implausible that at the same time the 15GP22 was being developed there was a 21" CRT in the works, but it had a worse yield and didn't get produced. RCA spent $6M in 50's money to develop the 15G and other companies like CBS made it woefully obsolete in a few months of production...I'm not sure if you would call that world leading development or getting a workable solution through brute economic force.

The working Apple Chromatron used beam index technology, not Chromatron tech. Code named Apple by Philco, it never got off the ground because RCA once again litigated in court to block the index beam set. The chief engineer in charge of the Apple, later started his own company in the early 70’s (Uniray) to bring to market the Apple. Alas, couldn’t raise enough capital, and the thing died. In 1981, Sony created a working 30 inch beam index tube, then Hitachi with a 1.5 inch.

No doubt there was a 21 inch prototype, being worked on along side the 15, and 19 inch tubes RCA worked on, just never released. You could call then engineering mules, until the 21AXP22.

stromberg67 06-20-2021 07:54 PM

I thought the 19TP22 was the large screen prototype that was similar to the 15G, but didn't go into production because RCA licensed CBS' color CRT technology that allowed phosphors to be directly deposited on the screen, which led to the introduction of the 21AX in the 21-CT-55 set. :D

etype2 06-20-2021 11:10 PM

RCA was pressured to release the 21AXP22 early because of competition from CBS Hytron CRT and the Lawrence Chromatron. It is true RCA abandoned the 19 inch color CRT for release to the public.


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