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Old 01-19-2017, 12:11 PM
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old_tv_nut old_tv_nut is offline
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Quote:
Originally Posted by zeno View Post
... Also the CRT's used a green phosphor
that was stunning. ...
This is a very interesting observation.

I believe by this time they had dropped the cadmium from the green (which made it brighter, but yellower, producing a cyan color bar that was very grayish). (The cadmium was determined to be an environmental hazard.) This means that the green formula was based on copper-activated zinc sulfide like everyone else's green, but there could be unique differences among makers depending on the use of co-activators like gold or aluminum. With the deletion of cadmium, the efficacy of the green was reduced such that it could be the limiting primary for tube brightness rather than red, for D65 color temperature. However, no TV manufacturers at the time setup for D65; they were generally much more blue/cyan, partly as a habit from earlier days. Zenith used a unique 8000K setup that was not as blue as others, but still had a clean white look that accented reds and yellows by contrast, and provided more stable skin tones. I don't know exactly what combination of activators Zenith used in green or the exact color coordinates of the resulting green. I also note that the "stunning" nature of a particular color bar can be influenced greatly by the color demodulator gains and angles.
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