Dave D wrote:

wrote in message
ups.com...

What do the plastic rings on the TV's CRT neck yoke do? Usually there
is more than a few and they are adjustable with tabs, I moved them
around; but they didn't change anything on the screen.



Why on earth adjust something you do not undertstand? Those 'plastic rings'
are there to adjust the convergence (the as near perfect as possible overlap
of the red, green and blue images) when the CRT is manufactured. Each ring
affects a different beam or part of the raster, and each ring can be
dependent on the others, making setup very tricky. They generally do not
require adjustment as part of a service, and they certainly must never be
touched by unskilled hands. Unless you have set them back exactly where you
found them you will certainly have messed up the convergence, and even an
untrained eye should be able to spot convergence errors on a CRT. Look for
coloured fringes around edges, teletext can be useful for this if you have
it You may notice letters that should be crisp and white now have two or
three seperate coloured letters not quite overlapping properly.

Dave

Hi...

If he's really, really lucky they may have had dabs of paint (nail
polish?) marking the original locations that he can use to return
them to their original positions

Course now we have computers and dvd burners, we can make our own
dvd's with dots and cross hatch patterns. Lots easier than in the
real old days carrying a huge, heavy B&K generator

Take care.

Ken