I'm ready to abandon my cable provider and install a TV antenna in hopes of getting free (almost) HD reception. I live on the sixth floor of a high rise building in Ottawa, Canada and the condo rules prohibit exterior antennas. A friend suggested using either the building plumbing or the ground circuit of our electrical service for an antenna. I remember using a hot water system for an FM antenna about 50 years ago and I had to attach a resister (I think) to my antenna wire so as to avoid stray current entering my radio. I'm loath to try anything until I get some advice about protecting my electronics from whatever current my be present on the pipes or the ground circuit. Any advice?