Line conditioners don't usually fix ground loops. At least that's my understanding.
In my system (and this is explained in detail in a recent post called "Ground Loop - New Twist?") the problem was that the cable installer had my cable entry grounded to a neighbor's electrical system (I'm in a "condo" of a sort). If the cable system is connected and the problem didn't exist before, that is, in all likelihood, the culprit. Look for info on CATV ground floaters like the Mondial Magic.
In my system (and this is explained in detail in a recent post called "Ground Loop - New Twist?") the problem was that the cable installer had my cable entry grounded to a neighbor's electrical system (I'm in a "condo" of a sort). If the cable system is connected and the problem didn't exist before, that is, in all likelihood, the culprit. Look for info on CATV ground floaters like the Mondial Magic.