With the June 2009 transition from analog to all-digital television broadcast signals, having a good TV antenna (and knowing how to use it) is more necessary now than ever. When television stations were broadcasting analog signals, if your television antenna had weak reception it meant a snowy or "ghostly" looking picture. With digital signals however, having weak reception means having problems with a scrambled or frozen picture; or even no picture at all. You might need to buy a different type of TV antenna. But before you invest in one, try making adjustments to the antenna you already have.
Adjusting an Indoor TV Antenna
Turn your television and digital converter box (if you're using an analog TV) on. Switch to a television channel where you've been experiencing weak reception. Activate your TV or converter box's signal strength meter so that you may monitor your progress.
Look for sources of "multipath interference" which might cause your TV signal to be reflected. The reflection creates a duplicate signal which interferes with the original signal, leading to weak reception. Raise your indoor antenna above mirrors and large metallic objects, like refrigerator doors.
Experiment with pointing your antenna in different directions. The towers for the different television stations in your area are located in different places. Therefore, your antenna will likely need to be aimed in different directions to pick up a strong signal from various stations. It takes a second or two for digital tuners to properly detect a signal, so move your antenna around slowly to each bearing as you monitor your progress. Try placing your antenna closer to a window.
Use the AntennaWeb.org website (see resources) to obtain a more precise heading of the tower coordinates of the TV stations in your broadcast zone. Use this if you're still having difficulty picking up signals for certain channels. After you type in your home address, this resource will give you the compass bearing (from your house) for each of the local TV station towers in your broadcast zone. Use this information to help your orient you antenna. Then perform channel scan to see if you are now able to pick up your missing channel.
Try using an antenna amplifier to boost your signal reception.
Adjusting an Outdoor TV Antenna
Mount the antenna higher. The higher the better, preferably above your building's roof line. For wood-frame buildings, mount the antenna at least 4 feet above the roof's peak. For flat metal roofs, mount the antenna at least 10 feet above the roof.
Orient your antenna on the side of your building that faces the TV signal tower(s) that have the weakest reception. (Only mount your antenna on the side of your building if you are unable to mount your antenna on the roof.)
Leave room for some mounting flexibility if you are using a multidirectional antenna. Move your antenna around in each direction while monitoring your television reception. When you find the orientation that produces the best picture, then permanently mount the antenna.
Things You'll Need
Digital converter box
If none of these measures are successful, you may be using the wrong kind of antenna for your needs. Make sure your indoor antenna is capable of picking up VHF and UHF channels.
Use the AntennaWeb resource to choose the most appropriate outdoor antenna for your location.
Towers, large buildings and trees can also cause signal interference.