[etype2]

Thank you, Wayne, Tom, consoleguy67, Electronic M.

“ They simply used existing primary color phosphors when they designed the 15GP22”… My understanding was the phosphors were designed to come as close to NTSC color specifications, after all the 15GP22 was the first color CRT introduced to the public.

“ Because the NTSC correct phosphors we're horribly dim and terribly unbalanced … “ I believe it was more of a problem of the shadow mask design. The first shadow mask blocked 86% of the electron light. RCA could have designed a more efficient shadow mask without changing the color phosphors, but I’m not sure it was technically possible at the time. It is true that later RCA CRT designs were brighter, but at the expense of color accuracy. As Wayne has explained many times, the reds became more orange and greens became more yellow. Precisely why the Chromatron and beam index tubes were developed, to overcome the inefficiency of the shadow mask.

Edit. Sidenote. Muntz tried marketing a Chromatron television.