DIY cable tv ground loop isolator. please help

[imperfectcircle]

I have a ground lopp problem with my cable box and lcd tv. Ive found the Jensen Isomax isolation device which goins inline with the cable tv cable buts like $60! Seems like alot of money for a pair of capacitors or a common mode choke, im not sure which method they use in thier products. I tried making a small transformer with some magnet wire and a ferrite core, it got rid of the ground lopp hum, but my digital cable wasnt able to reboot with it installed. So i think my little home made choke wasnt passing enough bandwith for the digital cable tv? Can anyone reccomend a suitable choke for this kind of use?? Ive also read that a pair of capacitors wired in series inline with the center conductor and sheild/ground of the cable tv line will redce the 60hz hum. Is this true??