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Is there any easy way to get a tv test pattern on my tv?

Is there any fairly easy way to get a tv test pattern on my tv screen?

Not the color bands but the circle.

The vertical doesn't seem linear.

It has a built in VCR and I have a DVD player. And a computer, and a long term plan to take the output of my computer and put it into my televisions. The plan hasn't even been designed yet, but if this is the only way to get the test pattern, maybe that will spur me on.

The tv is about 5 or 10 years old. If it really is not linear, are there still controls to adjust that? I know there arent' on the outside, but maybe inside?? It's a 12 inch Magnavox with a built-in VCR. I can get the model if it makes a difference.

Strangely enough, the parts that are inconsistent vertically seem to be different depending what is on the screen, even though I never see any movement in the picture. Maybe I'm going crazy so I'd like to know, even if I can't readjust the vertical.

Reply to
mm
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Get a CCTV video camera. Plug video (not RF) output into TV. Pick a test pattern:

Print on 1200 dpi laser printer. Point camera at pattern. Verify that the camera is linear in both horizontal and vertical by rotating the camera 90 degrees. The circle should remains a circle when rotated.

There used to be rotating test patterns on some obscure CATV channels.

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Reply to
Jeff Liebermann

If you have a video camera, take a picture of a circle(s). Feed the video to a tv you are happy with and see if the circle is round. If ok, then feed the signal to the tv in question. There are usually controls, but they are probably mounted directly on the printed wire board and may not be marked as such.

Reply to
hrhofmann

Gotcha.

No cable these days. Although maybe I could get a discount if I signed up only for obscure cable. :)

Thank you both. I only have a web cam, and come to think of it a digital still camera. The webcam isn't hooked up yet (but if I decide to take a big trip, I'll buy a netbook.)

Well, it's good that they might be marked.

This project is going to take a long time. But that's okay. Maybe by the time everything is ready to go, the non-linearity, if present now, will be a lot more visible.

Reply to
mm

I must be slipping in my olde age.

One does not use a circular pattern to adjust vertical (or horizontal) linearity. One uses the cross hatch or dot generators instead. I have used circles in the distant past, but they require a clear plastic overlay with fairly concentric printed circles to generate a Moire pattern. This is far more accurate (used for ancient radar PPI displays to center and align the range circles) than cross hatch, but major overkill for a TV set, which doesn't require such precision.

Many newer TV's have a built in cross hatch test or service mode. However, since the maker and model number wasn't supplied, I'll be lazy and not dig out how to get into the test or service mode. This might be a useful start:

There are also DVD's that can be played which generate various test patterns on the TV. I have one in my palatial office, somewhere, maybe (if I didn't loan it and forget about it). Also, I can't seem to find one with Google. Argh...

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Jeff Liebermann     jeffl@cruzio.com
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Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

Some DVD's, especially those with thx, have test patterns in the menus. There are also special test DVD's such as "Avia" or "Video Essentials".

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Reply to
Andrew Rossmann

I put the idea in your head.

Hey, speak for yourself. Nuthin's too good for my tv.

I'm sure this one doesn't have that. I don't think it would be called "newer".

Very interesting. I'll read more of it tomorrow.

I'll keep my eyes open for such a DVD. Thanks.

Reply to
mm

Thanks. If it's essential, I guess I need it.

Reply to
mm

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