Watch free HDTV with an outdoor antenna

WARNING: Proceed at your own risk and discretion. Please take proper safety precautions if you decide to install your antenna on the roof or another potentially dangerous location. CNET recommends consulting a professional for help installing a rooftop antenna. CNET is not responsible for any injuries or problems that may occur when installing an antenna.

Once you've oriented the antenna for best reception, tighten the screws and secure the rest of the antenna assembly. Then secure the coaxial cable run into your house, avoiding crossing other cables or power lines. We recommend you seal the outdoor leads (where the cable screws onto the antenna) with something called coax seal or RTV to avoid corrosion.

Important: Grounding
At this point you must ground the antenna to protect your valuable HDTV equipment from electrical surges. First, make sure all of your gear is plugged into a quality surge protector, preferably one that's guaranteed for at least the amount of your equipment cost.

Then attach a coax grounding block, available at any RadioShack, to a point near where the cable enters the building. Connect one length of your coax antenna cable between the block and antenna and a second length between the other end of the block and your HDTV receiver. Then run a length of grounding wire from the block to a suitable grounding point.

Grounding points can be a true earth ground (defined as a length of pipe driven eight feet or more into the ground) or a cold-water pipe. The best place to find true ground is at an electrical sub-panel, comms wiring closet or the building construction steel itself. If you use a pipe, make sure to remove any paint at the point to which you attach the grounding wire. Since in new construction many pipes are PVC along some of their lenghts instead of metal, they may not be reliable grounds.

You also need to ground the antenna itself by running another length of grounding wire between the antenna and ground point. Your antenna itself may have special instructions for grounding; if so, be sure to follow them. If you're not sure you've grounded your antenna correctly, consult a professional experienced in installing antennas or the manufacturer of your antenna itself.

With your antenna safely installed, you can now enjoy free over-the-air HDTV.