Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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

On Fri, 11 Dec 2009 20:18:14 -0500, mm
wrote:

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


Get a CCTV video camera. Plug video (not RF) output into TV.
Pick a test pattern:
http://en.wikipedia.org/wiki/Test_card
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.

Not the color bands but the circle.


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



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

On Dec 11, 9:28*pm, Jeff Liebermann wrote:
On Fri, 11 Dec 2009 20:18:14 -0500, mm
wrote:

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


Get a CCTV video camera. *Plug video (not RF) output into TV.
Pick a test pattern:
http://en.wikipedia.org/wiki/Test_card
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.

Not the color bands but the circle.


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

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
#http://802.11junk.com* * * * * * *
#http://www.LearnByDestroying.com* * * * * * * AE6KS


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

On Fri, 11 Dec 2009 20:25:02 -0800 (PST), "hr(bob) "
wrote:

On Dec 11, 9:28*pm, Jeff Liebermann wrote:
On Fri, 11 Dec 2009 20:18:14 -0500, mm
wrote:

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


Get a CCTV video camera. *Plug video (not RF) output into TV.
Pick a test pattern:
http://en.wikipedia.org/wiki/Test_card
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.


Gotcha.

Not the color bands but the circle.


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


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

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
#
http://802.11junk.com* * * * * * *
#http://www.LearnByDestroying.com* * * * * * * AE6KS


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


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.)

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.


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

On Fri, 11 Dec 2009 20:18:14 -0500, mm
wrote:

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


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:
http://myweb.accessus.net/~090/how2adj.html

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

In article , NOPSAMmm2005
@bigfoot.com says...

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.


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

On Fri, 11 Dec 2009 23:02:25 -0800, Jeff Liebermann
wrote:

On Fri, 11 Dec 2009 20:18:14 -0500, mm
wrote:

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


I must be slipping in my olde age.


I put the idea in your head.

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.


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

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


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

lazy and not dig out how to get into the test or service mode. This
might be a useful start:
http://myweb.accessus.net/~090/how2adj.html


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

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...


I'll keep my eyes open for such a DVD. Thanks.
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Default Is there any easy way to get a tv test pattern on my tv?

On Sat, 12 Dec 2009 15:50:00 -0600, Andrew Rossmann
wrote:

In article , NOPSAMmm2005
says...

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.


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".


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