Last week, more than 400 stations nationwide turned off their analog signals and went all digital as part of the DTV transition—and many consumers suddenly lost TV channels. That’s because digital signals can be harder to pick up by antenna than their analog counterparts. The Federal Communications Commission has launched a Web site http://www.fcc.gov/
mb/engineering/maps/ that might indicate whether you’re likely to have trouble.
Enter your ZIP code or address, and you’ll see a page listing your local television stations. (Click on image at right for a sample.) Click on a station and a box will pop up showing basic information about the station, including its direction and distance from your house—information you’ll need to choose and use the best type of antenna. It takes a little time for the stations in your area to load, so be patient.
At the bottom of the pop-up box, clicking on "Gain/Loss Map" will take you to a color-coded map (bottom image) showing where the station's signal is strong and weak. Green indicates good signal strength, yellow is moderate, orange is weak, and red means no signal. The maps are small, but you can enlarge them by clicking anywhere on the map.
The map also shows the outer limits of a station's broadcast signal, a dashed-line for analog coverage and a solid line for digital. This demonstrates very clearly that digital signals do not travel as far or cover exactly the same "footprint" as analog signals. That's why some households need a more powerful antenna to pick up the stations they got before, or find that they can’t pull in the digital version of a station at all.
Many more consumers will undoubtedly discover these inconvenient truths of physics as the rest of the country's television stations switch off their analog signals over the next few months. All full-powered stations are supposed to discontinue analog broadcasts by June 12th.
A site called AntennaWeb.org (sponsored by the Consumer Electronics Association and National Association of Broadcasters) offers a similar analysis of signal strength for specific addresses. Interestingly, it suggested signals for the address we provided would be weaker than the FCC site indicated.
In the end, the only way to be sure is to try it yourself. Start with an inexpensive indoor UFH/VHF antenna and tinker with placement and position before you even think about buying anything more expensive.