In the past 75 years, television programming has changed a lot. But, until recently, broadcasting technology hadn't. Today, digital broadcasting, using 1s and 0s, is widespread, running alongside regular analog TV service. Analog service ends in February 2009, freeing spectrum for use by public safety agencies and wireless communications, among other uses. This could affect your ability to watch TV.

Preparing for the transition

Broadcasters will bear the brunt of the transition, but individuals also could be adversely affected. When the change comes, your TV must be capable of receiving digital signals. Otherwise, you won't be able to watch TV.

If you have cable or satellite, you don't need to worry. Those companies will provide any necessary equipment. Telephone companies' fiber-optic service should also continue to work.

Does your TV have a digital tuner?

If you use an antenna, your TV will need a digital, or ATSC, tuner. Do not confuse this with NTSC tuners, which are analog. (ATSC stands for Advanced Television Systems Committee, which develops digital TV standards. NTSC stands for National Television System Committee, which developed analog standards.)

Laws have helped ease the transition for consumers. Since July 2005, digital tuners have been required in sets 35 inches or larger. The same requirement was imposed on sets 25 inches or larger in March 2006.

And since March 2007, all TVs have been required to have digital tuners. Stores can sell their existing inventory of analog TVs, but the TVs must be clearly marked.

All high-definition TVs are capable of receiving digital signals; older, standard-definition CRT TVs aren't.

What if you have an analog tuner?

Again, you will only have a problem if you use an antenna to receive your signal. Even then, you do not need a new set. There are other solutions.

Converter boxes will be available to translate digital signals to analog. Your TV must have inputs for the converter box.

The boxes should cost between $50 and $70 when they're available, but individuals won't have to bear the full cost.

The government has established a $1.5 billion fund to subsidize purchases. Households can apply for up to two $40 coupons. The coupons can be requested between Jan. 1, 2008, and March 31, 2009. They are valid for three months from the issue date.

A digital converter box will not give you a high-definition signal. Your old analog TV does not have enough pixels for that. The signal is downgraded to analog for these sets.

Your DVR may help

You can also use another gadget that contains a digital tuner. For example, a videocassette recorder, DVD recorder and digital video recorder with a digital tuner will work.

After connecting the recorder, you leave it on while you're watching TV. You change the channel on the recorder rather than on the TV. Your old TV still will display the picture as standard definition.

However, using this system, the signal is not necessarily downgraded. If you use a high-definition monitor, you can see an HD picture.

But there's a catch. You won't be able to record from one channel while watching another unless the recorder has two tuner cards.

You can learn more about the transition to digital television on the FCC's site and, the official website of the National Association of Broadcasters. You'll also find information on the coupon program.

Kim Komando hosts the nation's largest talk radio show about computers and the Internet. To get the podcast or find the station nearest you, visit: www.komando.com/listen. To subscribe to Kim's free e-mail newsletters, sign up at: www.komando.com/newsletters. Contact her at gnstech@gns.gannett.com.