I received an email recently asking what all the ads about TVs switching to the digital format mean  and how to tell if you need to take action. It's a really good question. For years lawmakers have been throwing around due dates, but full-power television stations in the US are required to stop using the old method of transmitting TV signals (known as analog) and start broadcasting exclusively in a digital format on February 17, 2009.
Ultimately, it's a win win situation for all us viewers. Digital television offers awesomely sharp pictures and sound and allows TV stations to improve their services with enhanced closed captioning and offer several channels of programming at the same time, known as "multicasting." (That just means there will be more great stuff for us to DVR or TiVo !).
Most major stations in the country are currently broadcasting in digital and it's very likely that your set is already converted, but millions of households risk losing television reception unless they take the simple steps to receive a digital signal. If you are wondering what you might need to do, .
According to DTV Answers , if you use an antenna to watch free, over-the-air television on an analog TV set (and don't subscribe to a pay TV service) then you will be affected by the transition. If you pay for TV services, such as cable or satellite, then you will not need to upgrade.