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  #1  
Old 01-28-2018, 03:20 AM
Outland Outland is offline
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Trinitron Visual Phenomena

I've noticed that Trinitrons appear to have a set of unique visual traits.

Are the following issues unique to Trinitron TVs or only to my example? I haven't seen this occur on shadow mask CRTs.

1) Horizontal "ripple." When there is a static picture on one side (for example, a square on the left side) and a moving bright object on the other (for example, white text scrolling up on the right side), when the text moves through the position of the square on the vertical axis, the square slightly deforms. If this is normal, why does this occur? I don't see how a bright object on one side can affect an object that only shares it's vertical position and nothing else.

2) Reflections. In the aforementioned example with scrolling text, when the text scrolls up and away, a white "reflection cloud" appears as the text passes through the top (or bottom) edge of the screen.

3) Reduced image. On almost all Trinitrons, I've noticed that the picture is slightly cut off on all sides and almost always a little lop-sided.

I'm just curious if there are any technical reasons for this phenomena.

Last edited by Outland; 01-28-2018 at 03:36 AM.
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Old 01-28-2018, 07:33 AM
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Don't forget Trinitron's orange-red. Red is never red....it's orange...
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Old 01-28-2018, 09:21 AM
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zeno zeno is offline
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Most of what you see is probably normal & not really the
TV. Old sets dont handle the cable boxes etc well. You can
try turning down the brite & contrast & see if it does better.
The bow effect is usually pin cushion adj. On 70's sonys there
was a little cap that was a common fail. You may also have some Overscan
that may be related to the pin problem BUT its normal to adj a
set to have a little.You may want to put up a screen shot & maybe
we can see something else as it sounds hard to describe.....

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Old 01-28-2018, 08:05 PM
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ChrisW6ATV ChrisW6ATV is offline
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I remember that the shape of the raster changed on my Sony KV-1922 depending on the video content and the specific colors on screen. It was easy to notice when the screen-saver mode was running in the early Atari 2600 game "Air-Sea Battle". That cartridge produced many combinations of horizontal stripes of different colors after the game finished.
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Old 01-28-2018, 08:09 PM
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ChrisW6ATV ChrisW6ATV is offline
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Having said that, one thing I still always liked about Sony color sets over all other brands was their superior high-voltage regulation. The raster may have changed shape a bit, but it did not "bloom" with brightness/content changes as almost every other set did. That vastly annoying effect was really noticeable in MTV videos when the channel logo was on the screen. If your set was not a Sony, that logo was going to jump all over the place with the fast-paced editing of most music videos.
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Old 01-28-2018, 09:44 PM
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Quote:
Originally Posted by Outland View Post
I've noticed that Trinitrons appear to have a set of unique visual traits.

Are the following issues unique to Trinitron TVs or only to my example? I haven't seen this occur on shadow mask CRTs.

1) Horizontal "ripple." When there is a static picture on one side (for example, a square on the left side) and a moving bright object on the other (for example, white text scrolling up on the right side), when the text moves through the position of the square on the vertical axis, the square slightly deforms. If this is normal, why does this occur? I don't see how a bright object on one side can affect an object that only shares it's vertical position and nothing else.

2) Reflections. In the aforementioned example with scrolling text, when the text scrolls up and away, a white "reflection cloud" appears as the text passes through the top (or bottom) edge of the screen.

3) Reduced image. On almost all Trinitrons, I've noticed that the picture is slightly cut off on all sides and almost always a little lop-sided.

I'm just curious if there are any technical reasons for this phenomena.
#1: nothing to do with the type of CRT. What you're describing is either high voltage ripple (due to the current draw of the bright text) or a slight change in sync clipping level due to the bright video. Most sets had a little of this, to varying degrees.

#2): This depends on the geometry of the frame of the grille allowing scattered electrons to go back into the edge of the visible screen; it also occured in some non-Trinitron CRTs

#3): Really? Do you mean black edges, like underscan? Not normal, and if it is underscan, should not appear on any consumer set unless something needs repair. Or are you describing a video game display that is deliberately sized small so that nothing gets outside the viewing area of a normally overscanned TV?
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Old 01-29-2018, 09:14 AM
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"a picture is worth a thousand words" how about posting one so we can see what your are describing.
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Old 01-31-2018, 05:54 PM
Outland Outland is offline
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Quote:
Originally Posted by old_tv_nut View Post
#1: nothing to do with the type of CRT. What you're describing is either high voltage ripple (due to the current draw of the bright text) or a slight change in sync clipping level due to the bright video. Most sets had a little of this, to varying degrees.

#2): This depends on the geometry of the frame of the grille allowing scattered electrons to go back into the edge of the visible screen; it also occured in some non-Trinitron CRTs

#3): Really? Do you mean black edges, like underscan? Not normal, and if it is underscan, should not appear on any consumer set unless something needs repair. Or are you describing a video game display that is deliberately sized small so that nothing gets outside the viewing area of a normally overscanned TV?
Great points.

3) I must have described it inaccurately, I meant overscan. Sony sets seem to have more overscan than others of the time period.

Quote:
"a picture is worth a thousand words" how about posting one so we can see what your are describing.
Good point.
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