Quote:
Originally Posted by Tom9589
A field sequential medical closed circuit monitor would not have used a -P22 CRT. It would have used a -P4 CRT.
|
IIRC CBS themselves made atleast one field sequential set with one of the prototype Shadow mask tubes that eventually became the 15G.
It was absolutely possible to make field sequential on a shadow mask tube and the converse was also done...Col-R-Tel made a color wheel converter for monochrome NTSC sets.
http://earlytelevision.org/col-r-tel.html
Prior to CBS color becoming standardized Zenith was one of the big players in the medical closed circuit color market. Before CBS color was on air there was a sizable closed circuit field sequential network between hospitals and medical schools to make surgical procedure education easier. I don't remember reading much about the replacement of that equipment with NTSC, but I would assume since it was costly and had a decent install base that it persisted into the NTSC era and that if any new recievers were needed after the 15G came on the market that engineers would have been tempted to use it. I'd bet you a cookie the last field sequential recievers receiving actual program material in the 50s were medical CC monitors.
Wayne/Old TV nut you are right the shadow mask implementation would be dimmer than NTSC on a shadow mask, but I think you overlooked the fact that the color filters in color wheel converters also significantly attenuate the light passing through them...I don't have the figures on hand, but I suspect the difference in brightness would not have been quite as substantial as one might think.