[ZLS]

  I have my Cable TV sitting between my speakers.  I switch off between watching and listening to TV through the speakers and listening yo my audio source.  I have what I believe a cable induced ground loop that I need to get rid of.  When I use my battery powered amp it does not exist.  What can I do, or what piece of equipment can I insert to rid myself of this bugaboo.  I tried a filter from part express that went between the cable line and box, but it created more problems than it solved. 
    If this question has been dealt with before i apologize, but I always have believed that there are no stupid questions. 

                                            Thank You

[ctviggen]

What specifically do you mean that when you use your battery powered amp, the hum does not exist?  For instance, can you use the battery powered amp to listen to TV without having the hum?  Does your TV control the sound?  In other words, are the outputs of the TV connected to your amp? 

Basically, what to do is to ensure that the cable coming into the home is grounded to the electrical/house ground.  Typically, the electrical/house ground is a copper rod pounded into the ground near the fuse box.  However, one can also ground to a metallic pipe, given certain conditions.  Regardless, you want to ground the cable to this electrical/house ground. 

If this does not fix the hum, strip the system down to something that works without the hum. Then add items into the system until the hum comes back.  Whatever you just added is what causes the hum. 

Also, the cause of the hum may not be what you think it is.  I had hum in two subwoofers caused by bad interconnects.  In my situation, I started with a complete system, and kept taking stuff out of the system until the hum went away.  I was shocked when I realized that the interconnects were causing the hum.  Nonetheless, replacing the interconnects stopped the hum. 

[Daygloworange]

Chasing ground loops is never fun. But more than likely sounds like it is in fact your Cable TV feed. I had a similar problem years ago. But honestly, don't remember how I rectified it. But it was a nasty buzzing sound.

Cheers

[craig223]

Search this site for info on transformers.  Had the same problem in '05.  Took the advice of others here and put a transformer (Jensen, Rolls) between the cable box and the preamp and the problem went away.

Good luck!

[Dan Banquer]

Search this site for info on transformers.  Had the same problem in '05.  Took the advice of others here and put a transformer (Jensen, Rolls) between the cable box and the preamp and the problem went away.

Good luck!

I would say the same! When two units using an unbalanced connection having their signal grounds earth grounded, you will get a ground loop with 60 Hz hum components. The transformer will isolate the two units and cure the problem. DO NOT USE CHEATER PLUGS TO DISCONNECT THE EARTH GROUND FROM THE UNIT IN QUESTION!!!!!!!!!
That will cause a safety hazard with possible injury and DEATH!
                d.b.

[ZLS]

    Thank you gentlemen very much for your help.  It never fails in reading replies to my inquires, that questions are raised that I should have anticipated.  So, besides learning about Audio (and Video) I get the additional bonus of learning how to logically frame my questions.

                                       Thank You Again.

[DSK]

...I had hum in two subwoofers caused by bad interconnects.  In my situation, I started with a complete system, and kept taking stuff out of the system until the hum went away.  I was shocked when I realized that the interconnects were causing the hum.  Nonetheless, replacing the interconnects stopped the hum. 

Bob, do you mean that you replaced the interconnects with shielded ones, or that the original interconnects were actually faulty?

[gnev]

The cable ground loop hum can be eliminated with one of these:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=180-075

The problem I have, is with the device in place the signal to the digital cable box is reduced.
Creating a new problem: Some channels stutter and cut out, but it eliminated the ground loop hum.
 

[ZLS]

aa   A Pig and a chicken are walking down the road.  They come upon a roadside diner that has a big sign in the window, "Breakfest Special All Day- Bacon and Eggs $2.99"  The chicken said lets go in.  The pig said whoa, wait a minute.  From you they're looking for a contribution, from me they want a total commitment!! 
    The channels the parts express filter cut out were the ones I liked to watch!!