Antenna Positioning and Interferences
Environmental factors are largely unpredictable. What’s best for one location may not be the best for another. Outdoor placement is ideal as an antenna will pick up more signals as it gets closer to the broadcast towers, hence clearer signals with less interference. A small antenna that placed indoors will perform better outside on a patio, or outside a window – especially if facing the cluster of broadcast towers. If outdoor mounting is not possible or preferred, place the antenna as high as possible, such as the attic.
Another big factor to the equation is your tuner’s ability, sensitivity, and selectivity. ATSC tuners have dramatically improved over the last couple of years, and now many digital TVs are have built in ATSC tuners. Check your TV model’s specifications or manual in order to see if your TV has a built-in tuner or not. Most TVs bought after 2007 should have it. If you do not have a digital TV, you will want to look into purchasing a converter box. Regardless of your antenna brand of type, because of the 2009 conversion to digital you will not see a picture with an analog TV unless you have a converter box attached.
Antennas and Digital Television
Federal law required that all full-power television broadcast stations stop broadcasting in analog format and broadcast only in digital format after February 17, 2009. If you have one or more analog TVs that receive free over-the-air television programming with an outdoor antenna or "rabbit ears" on the TV, you will either need a digital television (a TV with a built in digital tuner) or an analog television connected to a "digital-to-analog converter box" (which converts digital signals to analog signals for viewing on your analog set) in order to continue to watch programming from full-power broadcast stations.
Try Using Your Existing Antenna First
Prior to making any changes to your current antenna or antenna system, you should check to see if it will receive the digital signals being broadcast in your area. Connect your existing antenna to either a digital television or a converter box connected to an analog TV. Make sure your TV is set up to receive over-the-air broadcasts (as opposed to being connected to a paid provider such as a cable or satellite TV company). It may also be helpful to perform a "channel scan," in which your TV will automatically check to see which stations it can receive. In many cases, this is all you will need to do to watch digital television broadcasts. If you do not have any kind of antenna to run this test with, there are also other ways to test whether or not digital signals are being broadcast in your area.
During certain hours of the day or times throughout the year, many stations will temporarily operate at reduced power levels. If you are not receiving certain digital TV stations, this does not necessarily mean there is a problem with your antenna or receiver. Check with the TV station to find out whether they are planning changes that will improve reception.
When an analog TV signal is weak or receives interference, static, snow, and distortion will often appear on the screen, but you can watch the picture through the noise. Digital broadcasting will provide a clear picture even with a weak signal and in the presence of interference. However, if the digital signal falls below a certain minimum strength, the picture can suddenly disappear. This “cliff effect” means that if you typically watch analog TV stations that have a lot of static and distortion, you may have to adjust or upgrade your antenna system to get a reliably good signal for digital broadcasts.