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Old 12th Feb 2019, 1:36 am   #8
Lloyd 1985
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Join Date: Jun 2008
Location: Coningsby, Lincolnshire, UK.
Posts: 2,814
Default Re: CRT is brighter to one side [Hitachi CTP213]

Quote:
Originally Posted by InsertNameHere View Post
Would a shadow mask from a DG set not work on a PIL set and vice versa with the correct adjustments, or would it just be a mess?
No is the simple answer to that, the shadow mask is an integral part of the CRT itself, it sits just behind the phosphor coating, and the electron beam passes through it, it’s there to direct the 3 beams to their intended phosphor colour. Have a look on YouTube, I’m sure there was a video of someone dissecting a Sony trinitron CRT, or even some of the nasty videos of people bashing TVs with hammers, you will see the shadow mask as what looks like a sheet of metal behind the faceplate glass.

The video that Rambo1152 has linked to will show you a delta gun CRT being assembled, you get to see how the shadow mask is used during manufacture for positioning the phosphor dots (I can’t think of a better way to describe it!) and that a particular shadow mask has to stay with the faceplate it was used with.

If you want, I can get a close up photo of the slots in a PIL shadow mask, as I pulled one from a smashed CRT once.

Regards
Lloyd

Ps, the photo is of my HMV 2711 that has the Thorn 3500 chassis in it, and a 26” delta gun CRT, it’s a right pain in the backside to get the convergence good on it!! There is an old thread from when I got the set in 2009 on here somewhere, with shots of inside the set too, see how different it is inside to your Hitachi!
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