Hiya,

Ever since hooking up my PS3 I've had a problem with a ground loop thanks to it having a grounded power plug and my digital cable box going to the TV. Now, I can't move to a different outlet as I've tried that and I'm in an apartment.

Now I know I can get a surge supressor/protector with Coax support for the cable box and that should resolve it, however I already have more surge protectors than I need.

I will do that if I have to, but my question is that if I buy some really good heavily shielded AV cables for the cable box, will that be enough to shield the TV from the ground loop?

Hiya,

Ever since hooking up my PS3 I've had a problem with a ground loop thanks to it having a grounded power plug and my digital cable box going to the TV. Now, I can't move to a different outlet as I've tried that and I'm in an apartment.

Now I know I can get a surge supressor/protector with Coax support for the cable box and that should resolve it, however I already have more surge protectors than I need.

I will do that if I have to, but my question is that if I buy some really good heavily shielded AV cables for the cable box, will that be enough to shield the TV from the ground loop?

Short answer, No!! Only way is to tie the TV coax shield to the same ground as your power receptacle.


Jon

Read up on ground loops (if you have not already :) )

If the hum goes away when the STB is disconnected, there may be some thing you can do.

Although it might be difficult because you are in an apartment, see if some one can check (or call the cable company to have them check) the grounding block at the cable entrance. There must be one, and the connection from it to the ground rod or service panel must be tight and corrosion free and have a very low resistance. I've noticed that Comcast techs here often redo these as a matter of course.

Look here, http://www.siber-sonic.com/electronics/GLoopFix.html for some more info and check into the Cal Rad isolation transformer. You can buy one from here, http://www.bluejeanscable.com/store/rf/index.htm

Yea I called the cable company about it last night and they won't fix it. They say it's not their problem.

Also I was told the insolation transformer would cut my cable internet speed in half, and it's already very slow so I can't do that.

So is there no other way? One person told me the surge supressor with Coax would fix it and another said it wouldn't.

We need someone with more expertise to jump in here.

Looking at this link to , ISO-MAX VRD-1FF Cable TV Ground Isolator (http://www.cs1.net/cables/products/jensen_transformers/VRD-1FF.htm) the bandwidth is good and the insertion loss looks low to my eye. I don't see why a transformer like this would cut throughput for your internet connection by 50%.



Good luck.

We need someone with more expertise to jump in here.

Looking at this link to , ISO-MAX VRD-1FF Cable TV Ground Isolator (http://www.cs1.net/cables/products/jensen_transformers/VRD-1FF.htm) the bandwidth is good and the insertion loss looks low to my eye. I don't see why a transformer like this would cut throughput for your internet connection by 50%.



Good luck.

I have the Jensen transformer and it does work. Inserted between wall and television cable box it wouldn't have an effect on cable modem would it?

Well, when Comcast came to my house concerning ground loop problems, they simply attached a grounding wire from my cable splitter to the nearest A/C receptacle ground and that was the end of that. Basically they made a plug, but only used the ground. I don't like it but it works perfectly. 99.99% of ground loops are due to your TV cable not being tied to you house ground.

John

Well, when Comcast came to my house concerning ground loop problems, they simply attached a grounding wire from my cable splitter to the nearest A/C receptacle ground and that was the end of that. Basically they made a plug, but only used the ground. I don't like it but it works perfectly. 99.99% of ground loops are due to your TV cable not being tied to you house ground.

John

That's about the best way to solve it. Make sure your cable splitters are all grounded to your main house ground.

Well, when Comcast came to my house concerning ground loop problems, they simply attached a grounding wire from my cable splitter to the nearest A/C receptacle ground and that was the end of that. Basically they made a plug, but only used the ground. I don't like it but it works perfectly. 99.99% of ground loops are due to your TV cable not being tied to you house ground.

John

John-

I'm just curious. Do you now have both a grounding block at the cable entrance and somewhere down stream from that a splitter connected to a power outlet?

If you do it suggests to me that you may not have a good cable service entrance ground or the room power circuit has a poor ground wire or conduit connection.

Well, when Comcast came to my house concerning ground loop problems, they simply attached a grounding wire from my cable splitter to the nearest A/C receptacle ground and that was the end of that. Basically they made a plug, but only used the ground. I don't like it but it works perfectly. 99.99% of ground loops are due to your TV cable not being tied to you house ground.

John

The ground only plug to A/C receptacle is the same thing I attach my grounding strap to for working on my computers. The only scary part, was making sure I had the right wire before putting it on my wrist. ;)


-Jeff

The ground only plug to A/C receptacle is the same thing I attach my grounding strap to for working on my computers. The only scary part, was making sure I had the right wire before putting it on my wrist. ;)


-Jeff

No entrance ground! :eek: :eek: It is a universal safety requirement in the U.S. (at least as far as I know--Indian casinos may have different rules because of sovereignty) to ground cable with a grounding block at the entrance.

A grounding block looks like this-

http://www.cablesnmor.com/ProductImages/tv5001.jpg

It mounts on the side of your home and is connected to the household power grounding point by a number 8 or 10 bare wire. Some localities allow it to be grounded to the service entrance panel. It should never be connected to an outlet in the house.

If you live in lightning country you really don't want to not have this. Especially if you are strapped in at the grounding point.

It mounts on the side of your home and is connected to the household power grounding point by a number 8 or 10 bare wire. Some localities allow it to be grounded to the service entrance panel. It should never be connected to an outlet in the house.

Any idea whose responsibility it is to ensure proper grounding? Cable provider? Owner/renter? I was all set to go with the grounding to receptacle until seeing your post. Guess I'll call RCN first and ask them to check it out.

Sucks having to pull the HDMI cable from the set top box to hook my PC up to the TV and avoid the ground loop hum and scrolling white bar.

Thanks
mike

I can only relate my experience with Comcast (and the company before that) ; in this area they treat it as part of their wire. Every tech who who has ever checked the wire has given it the once over. The last guy out replaced it, not because it was bad, but because, replacing it was a sort of preventative maintainence to avoid future calls.

I can only relate my experience with Comcast (and the company before that) ; in this area they treat it as part of their wire. Every tech who who has ever checked the wire has given it the once over. The last guy out replaced it, not because it was bad, but because, replacing it was a sort of preventative maintainence to avoid future calls.

Called RCN (in the San Francisco area) and the phone support guy said they could have a technician come out to diagnose the problem (for $49.99 :mad: ), but they aren't allowed to repair. He said the actual repair would have to be done by an electrician, and basically implied that the problem was with the household wiring and not the cable.

- :confused:

I'll check the ground at the service entrance myself (per http://archive2.avsforum.com/avs-vb/showthread.php?t=621272\ ) and if that's all and well I guess I'll try the Jensen isolator mentioned above.

Thanks all!

Well Mike yet another reason for moving out of the City! Check out the grounding block first because it is also a safty issue and it might solve the problem. You might be able to call the City electrical inspection office. They might tell you the offical requirement.

Well Mike yet another reason for moving out of the City! Check out the grounding block first because it is also a safty issue and it might solve the problem. You might be able to call the City electrical inspection office. They might tell you the offical requirement.

Working on getting out of here, as soon as possible (might be a few years, though).

I popped open the service box and traced the ground wire until the point where it lead straight out to electrical pole in the sidewalk. I couldn't confirm whether or not it was grounded from up there, but the rest of the installation looked so clean I would guess that it was handled properly.

We had Comcast some years ago and the service panel is still there. The ground from that one went to what looks like a grounding post in the electric service panel (3 bolts on the top). Had ground loop issues with that provider as well, though.

Might as well give the isolator a try.

Thanks again
mike
*update* just wanted to mention that I picked up the isolator from Markertek and it worked perfectly. Can't believe I waited so long to try it. Games look crazy on the big LCD!

From time to time my Cox cable TV/Internet feed introduced HUGE horizontal hum bars into my TV system. When I unconnected the incoming cable coax all horizontal hum bars disappeared. To solve the problem I installed a Iso-Max VRD-1FF from Full Compass which completely solved my hum bar problems. Cable TV, both analog and digital and Internet are all working perfectly after installation.