Zenith 19" Chromacolor II service suggestions

[Kevin Kuehn]

I will have to try this again because it's a little difficult to visually process with the picture rolling. My impression was that the moire ripple pattern and location did not change, but as the picture content moves past it becomes more or less predominant. I suppose that effect could also happen because I had the DVD content paused(stationary picture) rather than random content change. Sort of gives the appearance of magnetic interference pattern. I wish I could photograph it better but my camera messes with it and often shows more of a moired rainbow pattern.

same

Originally Posted by old_tv_nut

So, the moire does not ripple or change polarity at all? Did not expect that.
Edit: or are you saying the ripples change but just stay prominent in the same area? That's what would be expected if it's caused by the interaction of the scan lines and the phosphor pattern. If this is the case, it shows it's not a signal problem because it is modified by the exact position of the scan lines.

[old_tv_nut]

Originally Posted by Kevin Kuehn

I will have to try this again because it's a little difficult to visually process with the picture rolling. My impression was that the moire ripple pattern and location did not change, but as the picture content moves past it becomes more or less predominant. I suppose that effect could also happen because I had the DVD content paused(stationary picture) rather than random content change. Sort of gives the appearance of magnetic interference pattern. I wish I could photograph it better but my camera messes with it and often shows more of a moired rainbow pattern.

same

Forget using the vertical hold, and adjust the height very slowly. Moire caused by the CRT should stay in the same area but ripple through.

[Kevin Kuehn]

Originally Posted by old_tv_nut

Forget using the vertical hold, and adjust the height very slowly. Moire caused by the CRT should stay in the same area but ripple through.

I'm not exactly clear on what you mean by ripple through, although I do see the spacing between the shading change, and if I continue changing the height the pattern can even change it's shape. I'm testing with a stationary picture. As Zeno mentions this may not be what most would consider a textbook moire. Sometimes it shows up in smaller area's, but it's more of a rippled shading effect rather than a distinct color changing pattern. If you look at shading at the tops of the two pictures it's almost more a sinusoidal pattern. The finer fingerprint on the right side of the green background is a camera artifact.

[old_tv_nut]

Originally Posted by Kevin Kuehn

I'm not exactly clear on what you mean by ripple through, although I do see the spacing between the shading change, and if I continue changing the height the pattern can even change it's shape. I'm testing with a stationary picture. As Zeno mentions this may not be what most would consider a textbook moire. Sometimes it shows up in smaller area's, but it's more of a rippled shading effect rather than a distinct color changing pattern. If you look at shading at the tops of the two pictures it's almost more a sinusoidal pattern. The finer fingerprint on the right side of the green background is a camera artifact.

You are describing exactly the kind of effects expected due to the CRT and not the signal circuits, so, case closed.