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Dave Carlson
10-06-2005, 04:49 PM
I am a new engineer at a small local cable access station. We have video hum, and a stationary transparent bar in our signal. I have eliminated most of the hum (v-roll). It was inductive. I still have the stationary horizontal bar in the video, on both channels, both in house and on air. I think it may be related to the fact that the video components are split on at least two of the three legs of the 3-phase power, and that the grounds in the building are notoriously bad.
Any ideas?

Thanks,

Dave

MiniFireDragon
10-06-2005, 09:26 PM
I'd get ground fault checking powerstrips to see, or maybe run them through a power filtering UPS unit. Also check for any running motors (aka Fans) near cables. I was video capturing and had a fan sitting on my cable line and it caused waves in the video. Also make sure speakers are sheilded and not next to video sources, can cause anomilies too.

JReble
10-07-2005, 06:59 AM
Also, if you have a cable TV feed connected to any of your equipment, you should try a ground blocker. It's amazing how the ground potential from the Cable RF system can bleed into your entire video system.

http://www.hometech.com/video/atten.html

Try #63400

Dave Carlson
10-07-2005, 11:17 AM
Thanks!
Dave