Quote:
Originally Posted by Tom9589
Thanks for the YouTube link. I particularly like the nostalgic last few minutes. It raised two questions about the 23GP22 CRT:
1. Was Motorola the company that designed and produced the first 23GP22s?
2. Why did the 23GP22 have such a short service life? Were the electron guns of inferior design/quality? Did the phosphors require so much drive that the electron guns just didn't last long?
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The way I understand it the 23
EGP22 was developed in 1965 by Motorola (and IIRC was a joint effort with national video or one motos CRT suppliers) to be the first American rectangular color since Westinghouse's failed recalled 1958 rectangular color CRT.
The EGP used a monochrome CRT envelope and was one of the only rectangular color CRTs with the HV button on the side. The EGP had a very orangey red phosphor which made achieving natural looking color difficult....add to that Motorola was using their single tube SODPIL color demodulator circuit which had weak green gain and required both hue and tint controls...this made natural color even more tricky to achieve.
Then on top of that the EGP had cathode emission life issues and an excessive number failed in warranty or shortly after.... I've read on VK that when the plant built to make them got dismantled to be used for something else that debris was found in a wash tank or similar and was probably contaminating the tubes and causing the early failure.
By the time these tubes were failing en masse other makers had developed 25" CRTs that had better reliability and most EGP sets were converted to those.
Doug/DRH4683 will tell you that the EGP is also dangerous to do a cataract removal on....I don't think he is the only member here that has had an EGP implode during a cat removal either.