Ground Loops

Agolk2

I have some questions regarding ground loops. I have a coax. cable connection the exterior of a project on which the TV's are getting interference from what appears to be a ground loop. Right now the coax splitter is grounded to a hose spigot on the exterior of the home. Any ideas of where to reroute the ground to avoid this, or any alternative options?

Thanks

__________________
Andrew Golkin
ANG Visuals
www.ANGVisuals.com
(703)898-4430

nap

when you speak of "ground loop", is this the grounding electrode system?

If so, the splitter needs to be connected to this. Hooking it to a hose bib is cheesy. Are you even sure the pipes are even metal? In todays construction, plastic water pipe is very common.

what makes you believe the interference is from the ground loop? If it actually is, I would suspect there are some problems in the electrical system that are putting current on the ground loop that need to be corrected rather the the ground loop actually causing the problems.

Agolk2

House was built in 1974 so not sure about the PVC.

The reason i think it is the coax cable and the ground loop is that there is also other video systems (xbox, etc.) connected to the TV but not the cable system and they do not have any interference. All are connected to the same outlet/surge protector.

What do you think?

__________________
Andrew Golkin
ANG Visuals
www.ANGVisuals.com
(703)898-4430

MALCO.New.York

I would bet that there is a bad Connection. IE, insulator NOT flush with connection seat or the like.

Describe the Video "Noise" you see on the screens. A Ground loop in a Video system is RARE!

The following picture is from Wikipedia as an example of the "Proper Connection".

WRONG!!!

The Insulator is SHY of the "Seat".



http://upload.wikimedia.org/wikipedi..._Connector.jpg

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MALCO.New.York

The other culprit is often the Set itself.

A loose/mal unioned connection post. This occurs from damage.

The tell-tale here is evenly spaced Cascading Dots .

__________________
Something to One may be Nothing to another!

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Agolk2

Purple and green lines scrolling vertically slowly across the screens in the house and a hum from the audio. I'm not claiming to be an expert, just have done a bunch of reading about the subject and so far it points to ground loops. I'm going to go outside and check the splitter connections on the exterior.

Thanks

__________________
Andrew Golkin
ANG Visuals
www.ANGVisuals.com
(703)898-4430

MALCO.New.York

Run the system in ALL HOME RUNS. As it SHOULD BE, and there is NO chance of a "Ground Loop"!

Just based on MY experience.

__________________
Something to One may be Nothing to another!

Ultimate Wisdom---------
http://www.youtube.com/watch?v=OW-cnizLDEE

acrwc10

Your problem may be that the Main panel is not properly grounded and since the coax is connected to the water line it may have a better connection to earth then the panel, this could cause the problems you are describing, DON'T GO IN THE PANEL AND TRY AND FIX THIS ! Call an electrician these types of issues can be very confusing to people who do not have a very strong understanding of grounding and bonding.

acrwc10

Malco, although the problem could be a bad coax connection, It is VERY common that a bad ground or neutral connection at the receptacle or panel can cause current on the coax. The issue can even be a life threatening issue if it is bad enough.

mdshunk

Actually, that's not true, particularly when you and your neighbor are served on the same transformer. If the neighbor has a service neutral issue, he could be passing neutral current on every available path. SOME of the neighbor's neutral current can be on all the coax shields in the whole house. I've seen it on more than a few service calls. The simple solution is to install a ground loop attenuator. It looks like a coax attenutor, but it breaks the shield.

Agolk2

Thanks Shunk. Does that degrade the signal, i.e. will it carry HD signals thru the coax as well? Where can one purchase those?

__________________
Andrew Golkin
ANG Visuals
www.ANGVisuals.com
(703)898-4430

mdshunk

The insertion loss is just about nil, so it's basically invisible to your TV's. All it does is break the braid. Where can you get one? I have no idea. I get them from a local supplier, but I just Googled 'F connector ground loop isolator' and got a heck of a lot of hits.

edit... you an RCDD, by chance?

Agolk2

Nope, know a bit about electric but I have no certs and don't perform the work in that field. I was asking for a personal project.

Thanks for the info!

__________________
Andrew Golkin
ANG Visuals
www.ANGVisuals.com
(703)898-4430

MALCO.New.York

As usual...............Thanks for the Education.

__________________
Something to One may be Nothing to another!

Ultimate Wisdom---------
http://www.youtube.com/watch?v=OW-cnizLDEE