sounds like you'll probably be ok with the RG59. just remember that AC is noisy stuff and if you do see any degradation in quality, at least you'll know where to look first. twisted pairs like cat5 etc. seem to be the most easily effected but you can also get quite a bit on coax depending on a number of factors, such as shielding on the power cables as well as proximity, voltage running on the AC side, as well as your coax quality. just to be safe quad shield should be run anywhere near AC. just not sure if it's available as siamese. rory should know, he seems to be the resident guru here.