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.