Wavy lines on tv reception (tapes too!)

[JudgeGarth]

For the past couple of nights I've been getting wavy lines on my cable tv reception (digital and analog stations from a cable box). I also get it when I play a tape that I know is good. It looks like the kind of interference you get when all the cables behind the tv are interfering with each other, but I have another cable/vcr setup in another room and the same thing happens. It doesn't happen all the time, but when it happens on one setup, it also happens on the other setup in the other room. I even get it on "unused" channels. Could it be a satelite/signal problem? I didn't think it would manifest itself that way. I thought you'd get macroblocking or something like that, but anyway, why would that affect playing a tape?

I haven't tried recording anything when it happens, so I don't have any screen shots to post. DVD's work fine, by the way.

[redwudz]

Bad house wiring? Near a TV/radio transmitter?

When you say 'wavy' lines, do you mean the picture is distorted or the lines are imposed over the undistorted picture?

Are the lines smoothly wavy or jagged like a sawtooth pattern?

Are the lines covering the whole screen?

I got wavy lines on my cable TV when one of the local public service vehicles transmitted next to my place. In my case, it was the cable from the pole to my place with a corroded connection.

Noise or interference can also be transmitted over a power line, but it usually only happens with a large transmitter nearby or poorly grounded house wiring.

If you have a older place, you may have problems with your wiring. Are all your outlets and any extension cords 3 wire?

You might want to try recording it, mainly to see if it shows up on the tape.

I would also take a close look at your cables. Especially the ones from the VCR and satellite box to the TVs.

[edDV]

Other things to try.

Turn off everything except the TV. Disconnect everything from the TV except the cable from the cable company. If that is clean then try the cable box. Keep adding equipment one by one until you find the source.

Try powering everything connected to the TV from the same circuit breaker in the house wiring.

[JudgeGarth]

Thanks. I'll give those a try when it happens again.

The lines are smoothly wavy (actually, they look like a bunch of right parentheses). They're superimposed over the undistorted picture. They cover the whole screen and they slowly move up the screen.

[edDV]

Thanks. I'll give those a try when it happens again.

The lines are smoothly wavy (actually, they look like a bunch of right parentheses). They're superimposed over the undistorted picture. They cover the whole screen and they slowly move up the screen.

"Slowly move up the screen" means a power or ground loop influence. If you saw horizontal movement it would be more likely interference from another piece of equipment nearby with unlocked video.