A rooftop antenna allows you to watch more television stations by picking up broadcast signals that are too weak for your indoor antenna to recognize. Omnidirectional antennas receive signals from all directions equally, but directional indoor antennas receive signals according to their orientation. For this reason, it is important to point a directional rooftop antenna toward the broadcast towers of the stations you want to watch.
Locating Broadcast Towers
If you know a specific television station in your area that you would like to watch, you may be able to find the location of their broadcast tower through their website or by calling them. If you are using your directional rooftop antenna to receive more stations in general, and do not have a specific station preference, you can use online tools to help you find the location of all the television stations in your area. HD TV Antenna Labs has a broadcast search tool at Hdtvantennalabs.com. Another search tool is available from Antennaweb.org.
Use these tools to locate the television broadcasts in your area, and note the compass direction of the stations relative to your home. In some cases, the stations will be in opposite directions from your home, and you must choose which stations you are most interested in receiving.
Adjusting the Antenna
Before adjusting your antenna, you need to figure out which end of your antenna is the front. Outdoor antenna designs vary between manufacturers, so check the owner's manual of your antenna. If you have an antenna made by Yagi, the front end is the side with a single pole extending outward.
When going to your roof to adjust the antenna, bring a compass and a list of the compass directions of the stations in your area. Hold the compass next to the antenna, and level with the ground. Align the compass so that the arrow is over the mark indicating north. Use the markings on the compass to determine the direction to the broadcast towers, and turn your antenna so that it points in that direction.
If there are several broadcast towers in your area, located in different directions from your home, you may want to try several different orientations for your antenna. Some stations may only be picked up when the antenna is pointed directly at them, while others will be received even when the antenna is at an angle. In most cases, you should point the antenna at the stations you are most interested in receiving, or the stations with the weakest signals, but you can also experiment to see which orientation receives the most channels.