Ground Loop Isolator Install Question (1 Viewer)

[Earl J]

Sorry if this is a stupid question. I did a search and found way too many responses that didn't answer my question. I went to Ratshack and asked for the ground loop isolator. The one that they gave me has two rca jacks on both sides of the isolator. Did I get the right one? If so, what two components does it go between. I believe my grounding problem comes from the cable box since the humm goes away when I disconnect the coax from the cable box. However, my cable box does not accept rca connectors, only coax. Any help is much appreciated.

 

[Mike Strassburg]

Earl J,

I just installed the very same one you bought, between my PC and receiver & it worked great. Unfortunately you have the wrong one for a cable issue. Sorry but I don't remember which one you need. Either do a search or ask the guy at RS....

 

[AntonS]

There are isolators that physically disconnect gounds between the line and the cable box (I think they work as minianure transformer coils.) I don't think RadioShack sells them though, but I might be wrong.

I had ground loop problem with cable box too. I completely solved it by grounding the cable. RadiShack does sell a connector that accept cables at both ends, plus a grounding wire. It's about $3. Put it between the incoming cable and the one that goes to the box, attach grounding wire and run it to the ground (center) connector of any power outlet. If you don't want to spend $3, just somehow attach (just twist it on) the wire to the shield of the incoming cable.

 

[Gail M]

Hey Earl,
Some other HTF member recommended this many times in the past. I know he won't mind if I borrow his link to help you. Use the bottom unit in the picture. Link Removed

 

[Earl J]

Thanks for the advice all! I'll bring this thing back to rat shack and try to get the right one.

Earl

 

[Brian Treinen]

Earl,
DO NOT use a cheater plug.
Ok, now that that's over, I got an RF isolator from ratshack which was "supposed" to stop the hum caused by the cable TV, it was $2.99 and it didn't work. I then bought a grounding block, put in the cable line and grounded it to the ground screw on my amps chassis, didn't do anything. Lastly I used a 75Ohm --> 300 Ohm transformer connected to a 300Ohm --> 75 Ohm transformer in line on the cable TV line. BINGO!! No more ground loop hum.
Prior to trying the last thing I even connected the cable outside to our Satallite and electrical ground which helped a lot but didn't kill the hum all together.
Here's a link. http://www.dplay.com/tutorial/cablehum.html

 

[AntonS]

I then bought a grounding block, put in the cable line and grounded it to the ground screw on my amps chassis, didn't do anything.

You amp chassis is not necessarily connected to the ground. Moreover, the grounding screw on the chassis is probably for connecting external ground to it, not for connecting something else in hope it will give you the ground. My guess is that when you connected the cable to the gounding screw, you actually did not do anything.

Earl, just take a piece of wire, put one end into the ground (center) pin of a power outlet, and touch the cable connector with the other end. If the hum goes away, that's all you need.

 

[Earl J]

Brian, thanks for the link. I went to Radio Shack with those two part numbers. After a couple seconds to put them together, I installed it at the back of my cable box. And...........Silence...............The humm is gone.

Thanks for all your help everyone! Damn I love this forum!

Earl

 

[Earl Simpson]

Me too. It's good to see another earl!!!!

 

[Brian Treinen]

Brian, thanks for the link. I went to Radio Shack with those two part numbers. After a couple seconds to put them together, I installed it at the back of my cable box. And...........Silence...............The humm is gone.

Earl,

Glad I could help. When I got my new amp I was soooooo excited to get everything wired when I finally turned it on and heard the hum my heart sank! I used a cheater plug just so I could hear everything but knew it wasn't moret than a 30 min solution. I also didn't want to have to spend $100 on a solution. I found that link and dug into my "goodie box" of old parts and unused crap that's come with various electronics - low and behold I had THREE of each of the pieces I needed! Bring on the hum!

Glad I could help and give a little bit back!

 

[Earl J]

Earl,
I know what you mean. We're pretty far and few between now a days. It's especially difficult in my line of work because I deal with a lot of far east asian clients. They call me everything from Arrow, Ell, and Ow, to Raul, Al, and Ello.
Brian,
After months of humm, I was so happy to watch a dvd last night with only the sounds I'm supposed to hear. Thanks again.
Earl