America was still in black and white in 1954

[LMELTON]

https://www.youtube.com/watch?v=4ztRT0pdFWo

[old_tv_nut]

Wow. More AI-voiced crap, written by someone who did 7th-grade level research and glommed onto one scientist's papers. I fear this is evidence that the true history of technology is going to be obliterated in favor of AI hallucinations in the future.

At the start and later the author confuses the Rose Bowl and the Rose Parade. It was the parade that was broadcast in color to a few demonstration receivers across the U.S.

Problems with wrong color had everything to do with circuit drift and nothing whatsoever with the phosphors being wrong. Anyone with the least knowledge knows that the first NTSC sets had the correct phosphor colors, which were quicly followed by revisions to the phosphors that sacrificed the correct hues for more brightness, which was desperately needed as soon as sets went from 15 inch to 21 inch tubes.

6:35 shows the responses of the cone cells in the eye while talking about the phosphor primary colors RGB for a long time withut showing them, then finally mentions the cone cells.

~ 7:39 "The phosphors drifted" - absolutely untrue. There is such a thing as slow phosphor burn in, but this is at an unnoticeable level unless the tube displays stationary high brightness patterns like early video games. Random program material smooths out the burn-in completely.

~10:54 its "phosphors" "in the broad sense," not "phosphorus," dummy.

Ernest Bush (spelling?) may indeed have solved aging problems, but he must have done it before the 15GP22 in 1953, as evidenced by the good tubes we still have. To blame the variation in color programs as written by the newspaper critic on phosphors rather than circuit instability is nonsense. There was no certain direction of color change in receivers from program to program, and long term change in the picture tubes themselves were due to diminishing emission, the same as black and white tubes.

~13:38 Shows a rare-earth tube spectrum and says RCA was using it in 1953. More confused BS. Rare earth phosphors went into use in the 1960s, solving the low red efficiency problem and becoming normal practice for all subsequent CRTs.

~15:40 shows the emission decay after excitation removal at microsecond time scale, totally irrelevant to the aging problem being discussed. The preceding section also seems to confuse phosphor nonlinearity (which can cause off-color highlights in tubes with high intensity beams, like rear projection sets) with the long term burn in that this video seems to be all about.

~ 16:40 the rare-earth vanadate phosphor was introduced to production much later than the 1953 time frame claimed in the narration.
The following narration about the research appears to be about studying vanadate phosphors and solving a problem prior to their introduction, nothing to do with variations of color in sets that had already been put in production and sold to the public. Again, those variations were due to tube circuit instability and the difficulties of setting up. 3-tube image orthicon cameras.

~18.38 NTSC was not "designed around a wavelength of 611 nanometers." This would be a spec for a laser display. NTSC was designed around the color of a particular red phosphor, which had a broad band of emission compared to a laser.

~20:16 this is obviously work on probems with rare earth phsophors prior to ther introduction into product. RCA published data on vanadate phosphors (and IIRC, used them for a time before going to Yttrium oxysulfide. Before the vanadate, there were a few years of all-sulfide tubes, which were a step up in brightness, but had poorer color as the cadmium sulfide red was quite non-linear and turned orangy at high beam currents.

~21:49 long description of the same scaling up process for production that many other companies were doing for their phosphor development; Sylvania was a major force in rare-earth phosphors, and Motorola had worked on the all-sulfide phosphors that preceded them.

~23:06 The "improvement" in the green phosphor was to go from the orignal Willemite (P1) green to a brighter but incorrectly yellowish sulfide phosphor, not from a fictitious early sulfide green. The 1958 and later tubes mentioned definitely did NOT "match what NTSC was designed to deliver." The brightness of sets improved but the color got worse until set makers changed the gains and angles in the color demodulators to correct skin tones and correct other colors approximately.

~24:07 Shows a late 1960s RCA receiver ad with the stupidly incorrect date of 1954 above it. There were no rectangular tube sets sold before the late 60s.

~27:00 and following. The first sets using the 15GP22 produced correct color, not wrong color as claimed. Any instability was due to the tube circuitry, not the phosphors.
Bush's (sp) work was obviously done to fix problems BEFORE with vanadate before any tubes used it. Later tubes actually produced wrong color in favor of brighter images. Dim images were the problem with early 21 inch sets, not wrong color, as the 21AXP22 used the original NTSC phosphors, and were naturally dimmer than the 15GP22, which scanned roughly the same bean current over a much smaller image.

[ppppenguin]

I live in a PAL country and have grown up with the Never Twice Same Colour stories. Well engineered NTSC is very good indeed. The problem is that making it work well with the valve (tube) technology of the 1950s was a bit too hard. I have personal experience of early solid state PAL encoders. Many drifted horribly.

There is a story, I don't know how true, that the Soviet bloc adopted SECAM for technical reasons. Politically the French "sold" it to them but technically it was a good fit for their huge transmission systems. It's also said that their VTRs "Quad-ski", a Russian copy of the Ampex machines, didn't have the "Colortec" fine timing correction that was needed to replay PAL or NTSC. SECAM just needs monochrome timing accuracy.

[Electronic M]

Originally Posted by old_tv_nut

Wow. More AI-voiced crap, written by someone who did 7th-grade level research and glommed onto one scientist's papers. I fear this is evidence that the true history of technology is going to be obliterated in favor of AI hallucinations in the future.

~24:07 Shows a late 1960s RCA receiver ad with the stupidly incorrect date of 1954 above it. There were no rectangular tube sets sold before the late 60s.

I have the same worries about AI stuff and I wish YouTube would put a warning on AI videos for people who don't want to watch them.


One small nit to pick.
The first rectangular color sets were sold by Westinghouse and CBS in 1957...They ended up mostly recalled, but a few survived that. There's even a Sam's Photofact on them.
https://earlytelevision.org/westinghouse_h22t155.html

Didn't the 23EGP22 sets come out in late 1964 as 65 models?

[old_tv_nut]

Originally Posted by Electronic M

Didn't the 23EGP22 sets come out in late 1964 as 65 models?

I think that's right. RCA brought in rectangular sets in 66-67, which is nicely illustrated in their magazine ad progression. The earlier ads featured mutiple roundy models and one rectangular, then the later ads featured multiple rectangular sets and one roundy. There were a couple of ad pages with the exact same layout except for round vs. rectangular set count.

[old_tv_nut]

ATTENTION: I wrote the above corrections post late at night and may have remembered the exact dates of the introduction of different phosphors wrong. Introduction of vanadate rare earth may have been as early as 1958 as claimed, but I'm not sure.
Sylvania advertised their rare earth "Color Bright 85" round tube in 1965, and the all-sulfide tubes (previous to rare earth) were in use in the early 60s, so the 1958 date for vanadate needs verification.

[old_tv_nut]

Another thing stated near the beginning and end of the video needs correction, that the blue skies in the early sets were too purple. I wonder if this is a comment picked up from the newspaper review by the AI. This could have occurred on a particular broadcast viewed on a particular misadjusted early set, but definitely was not a feature of the phosphors.

The 15GP22 and early 21AXP22 tubes used the NTSC blue phosphor, which was more cyan and less deep violet blue than RCA originally wanted to get maximum deep blue and magenta saturation. RCA had trouble using the sulfide blue they wanted because copper contamination would turn the blue phosphor to green, so they settled on a different phosphor that did not suffer from copper contamination.

Later, at a time I have never found documented, when the copper problem was fixed, the 21 inch blue phosphor was changed to the more violet-blue zinc sulfide (with silver activator). This is the point at which the phosphor choice would make blues more purple and also yellows more greenish. RCA had chassis for a few years in which the color demodulators were not redesigned for the changed phosphor. Eventually, some time after the green phosphor was changed from P1 to the yellower zinc sulfide (deliberately doped with copper!), the demodulator gains and angles were changed to partly compensate for the colors of the new phosphors, particularly the green but also the blue.

Zinc sulfide with silver blue has been used for CRTs ever since, all the way through computer displays and HDTV, and is the blue primary for sRGB color space in jpg images.

[old_tv_nut]

More about confusion of emission decay with non-linearity (around 15:00 or so):

The sulfide phosphors (blue and green) did suffer from non-linearity at high beam current density. The rare-earth reds did not. This was not a problem in direct-view CRTs as the current density was not too high (except in Zenith's tri-potential tubes, which had too sharp a beam at optimum focus, turning highlights pink).

Projection sets however, had a very noticeable shift in highlight color. The green phosphor nonlinearity was fixed variously by going back to P1 phosphor (Zenith) or in some sets by using a rare-earth green, which, however, suffered from producing a paler desaturated green color. The blue phosphor nonlinearity was compensated with an opposite non-linearity in the blue video driver.

[N2IXK]

Another bit of AI slop that jumped out at me was at 19:07 in the video, where we see a process flowchart presented as part of the phosphor production process, but if you actually look at it, it is a flowchart showing how used CRTs are RECYCLED at end of life, and the rare earth elements reclaimed....

These AI videos really seem to be proliferating of late, including several on early TV technology and the demise of the TV repair industry. All share anomalous images and vague descriptions, as well as an apparent lack of review by anyone who actually knows the subject matter.

I also notice that some of the same subjects and images seem to appear across several of these AI content YouTube channels. I wonder if the channels are actually run by the same entity, or just using the same generative AI?

[etype2]

Re: Rectangular color tubes. My first color set purchased new, August, 1966, was an RCA CTC-19 Bremanger with 19 inch rectangular CRT.

[old_tv_nut]

The Performance of Color-Television Picture-Tube Phosphor Screens
Austin E. Hardy
[Radio Corporation of America Electronic Components and Devices, Lancaster, PA]
IEEE Transactions on Broadcast and Television Receivers
Year: 1965 | Volume: 11, Issue: 2 | Journal Article | Publisher: IEEE

Hardy's list of red phosphors stops with yttrium vanadate rare earth doped with europium, so apparently the yttrium oxysulfide:europium was not yet used by RCA.

[old_coot88]

Originally Posted by etype2

Re: Rectangular color tubes. My first color set purchased new, August, 1966, was an RCA CTC-19 Bremanger with 19 inch rectangular CRT.

As a dealer, our first unboxing of a '19 was one of those choir music moments on first beholding a 'sacred object'.
Never foresaw the 6GH8 legacy of the '19 and its derivatives.

[dtvmcdonald]

Originally Posted by old_coot88

Never foresaw the 6GH8 legacy of the '19 and its derivatives.

I never understood why no company simply made a replacement for that tube with higher specs for power dissiption.

Presumbly they would have to be a bit bigger, and thus occasionally not be retrofittable, but fine for new manufacture.

[etype2]

Originally Posted by old_coot88

As a dealer, our first unboxing of a '19 was one of those choir music moments on first beholding a 'sacred object'.
Never foresaw the 6GH8 legacy of the '19 and its derivatives.

I have a spare CRT for this set.