i'm looking for an inexpensive, but well shielded f-type coax cable. 3-10 feet in length and under $10. any suggestions? i have a standard RCA-brand one that's 50' (got it for $2...what a steal!) but it's delivering a picture quality that looks like scat porn alot of the time. when i move it around the signal improves; i'm thinking that b/c it's near my computer and power supplies that interferance is making the picture undiscernable. i've verified that the signal from the wall is good by use of a friend's tv on the same circuit. thanks in advance!