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Old 14th Feb 2019, 10:08 pm   #35
19Seventy7
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Location: Essex, UK.
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Default Re: CRT is brighter to one side [Hitachi CTP213]

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Originally Posted by Maarten View Post
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Originally Posted by InsertNameHere View Post
If delta is a higher resolution, why did CRTs become PIL, or is that just for monitors, which could be capable of a better resolution when the user is closer to the screen?
No need to have a much higher resolution than 576*768 for 625 line PAL (the shadow mask may have a somewhat higher resolution to prevent interference patterns and always give the impression of a sharp image). Also, Sony got away with relatively coarse aperture grilles, even in computer monitors, since they had a theoretically unlimited vertical resolution.
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What sort of mechanical stress can implode them?
Since it already has to withstand thousand kilogram or more of force, it takes a lot of concentrated force to crack the glass. For example a hammer strike, a shotgun shot, but also stress within the glass (spontaneous or temperature related). Picture tubes are pretty safe but not indestructible and when they fail, they should fail as safely as possible, hence either the safety glass plate or the pretensioning.
Would the sony sets be in question the Trinitrons? I think that they have a special shadow mask, i'm not sure... if they do, not sure if the shadow mask design is used in any other sets, sony or not.

If they had almost unlimited vertical resolution, couldn't something similar be done for horizontal, making a very high resolution CRT?

What is the chance of the glass failing? Couldn't an extra measure be taken, and pretension the CRT and have the safety glass?

Thanks
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