The federally mandated switch to digital television in the United States took place June 12, 2009. Since this date, U.S. TV broadcasters are no longer permitted to transmit over-the-air analogue TV signals and must now broadcast exclusively in digital format. For viewers, this change comes with a few perks such as the availability of more local TV channels. On the downside, because of the nature of how digital TV signals are formatted, for some this change may also lead to reception problems.
Evaluate the terrain where your home is located. The environment's obstacles, encountered by a TV signal as it travels from a TV station's tower to the antenna on a TV set, can weaken the signal. If your home is down in a valley, within the path of a hill, in a city or heavily wooded area, you could receive a weak TV signal. Broadcast TV signals are encoded into radio carrier waves and are transmitted throughout a TV station's service area via the station's broadcast antenna tower. As a TV signal travels over distances, it's subject to degradation. Because digital TV signals are encoded into the radio carrier waves as a series of zeroes and ones, the signal is received by your TV as either "on" or "off." Therefore, unlike an analogue TV signals which fade as they degrade, when a digital signal degrades it simply goes out. A weak digital TV signal often means no TV signal at all. And no TV signal means no reception for the channel you're trying to tune into.
Examine the immediate environment where your TV is located. Look for large buildings or trees outside the room window(s) where the TV sits. Look around the room for any large metallic objects, such as a refrigerator. These objects and obstacles can create multipath interference reception problems. Multipath interference occurs when a TV signal is duplicated due to reflection as it bounces off of certain kinds of objects. These duplicated signal(s) reach the TV antenna just a little later than the main TV signal. This creates interference, which works to either weaken or cancel out the main TV signal.
Purchase a better-quality indoor TV antenna. If you suspect that you might have multipath interference problems, a high-quality indoor directional antenna, accompanied with an attenuator pad, would best suit your needs. The attenuator pad works to slightly reduce the strength of the TV signal to a level where the presence of duplicated signals won't cause interference. If you suspect that the reception problem you're having is more likely caused by weak TV signals, a high-quality multidirectional TV antenna, accompanied by an antenna amplifier to boost TV signals, would best suit your needs. Whichever type of antenna you buy, be sure to purchase an antenna that is capable of picking up both VHF and UHF TV signals.
Position the indoor TV antenna for the best reception results. Raise the TV antenna above metallic surfaces to reduce the possibility of multipath interference issues. Move the antenna closer to an unobstructed window where the TV signals are likely stronger. Also try orienting the antenna at different angles to get the best reception results for different TV channels.
Invest in an outdoor TV antenna. If purchasing a better-quality indoor TV antenna does not resolve problems with a weak TV signal, you probably need to install an outdoor TV antenna as well. The Federal Communications Commission recommends that consumers use the non-profit AntennaWeb (see the link in the Resources) to help pick out the right type of outdoor TV antenna for your needs.