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Old 05-14-2019, 12:20 AM
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etype2 etype2 is offline
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Quote:
Originally Posted by old_tv_nut View Post
A slight correction - the Trinitron fine horizontal wires were added to reduce vibration of the vertical wires, not to alleviate effects of heating. The Trinitron vertical wires were under tension until heated very excessively, which normally could not happen with the current densities that could be reached in a normal chassis design. Edit: on large Trinitron tubes, knocking on the face would vibrate the grille, and you could plainly see the effects of the grille wires ringing.

Self-supporting shadow masks were subject to local expansion if there was too much local current, like the white patch in composite color bars/white/I/Q pattern. This could not happen with the Trinitron tensioned grille or the later Zenith flat tension mask tube. Self-supporting masks also were subject to overall expansion due to average temperature, and mounting techniques were developed that moved the mask closer to the phosphor screen as it warmed up and expanded over-all, thus maintaining design aim-point beam landing and good purity.
I can see the horizontal wires preventing vibration, especially in field monitors, but knowing that a shadow mask or aperture grill heating up and warping slightly could cause mis-registered color, it seems likely the tungsten wires also helped prevent warpage. Your comment about the slot mask connections make sense to prevent warpage.

Edit: I stand corrected. The aperture grill will warp, but not in a way that cause mis-registered colors, so I guess that’s another advantage over delta gun CRT’s.
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Last edited by etype2; 05-14-2019 at 02:34 AM.
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