Quote:
Originally Posted by Kevin Kuehn
Terry,
You sort of lost me here. I'm not exactly sure what you're asking, or how to go about checking for it.
Thanks again for all the help, I'm learning stuff.
Kevin
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Hi Kevin,
From your earlier photos, it appeared as if the horizontal retrace time was too long. That would mean that as the beam is swinging back to the left and if the active video in the signal begins to modulate the CRT beam before the beam reaches the left, then stretched ghost like images (including the white line) will appear in the picture. That is why when you adjust the horizontal hold, the white vertical line moves to the left when the picture moves to the right.
Note that about 10us is allowed to for retrace in the signal. The set has to to be able to retrace within the 10us.
A good test for retrace time is to see if you can see the edge of the active video on the left. When you shrink the scan or shift the raster so you can see the left of the image, up the brightness a bit and you should see a narrow black vertcal band prior to the vertical edge of the active picture. If you do not or if you see the image folded over, then something is wrong.
I only mention this because I had the impression something was wrong with the retrace time from your photgraphs. The same fault also may affect linearity.
Can you hift the raster to the right and photograph the left of the picture?
Thanks,
Terry