Do you need a digital converter box for your TV?

On Feb. 17, 2009, major U.S. television stations will stop broadcasting analog signals and send only digital transmissions. Some questions and answers about the transition:

- Why is this happening?

Stopping the analog broadcasts will free up a huge amount of airwaves. The government has auctioned off some of them for use by wireless broadband and cell-phone TV. There's also a drive to use some of the spectrum for a network that can be used in emergency situations by public safety officials.

- Do I need a digital converter box?

You do if you use a "rabbit-ear" or similar antenna on an older TV. More than 19 million U.S. households have at least one set that receives over-the-air signals, according a survey by Nielsen Co. Sets hooked up to cable or satellite service are not affected. Most new TVs sold today, including flat-panel sets, won't need a converter box because they have a built-in digital tuner, also known as an "ATSC" tuner.

"NTSC" is the old, analog tuner standard. Retailers can still sell older TVs if they are labeled as being analog-only.

- How much do the converters cost?

Go to www.dtv2009.gov or call (888) DTV-2009 " (888) 388-2009 to get up to two $40 coupons per household. The converter boxes generally cost $50-$60, so the final cost is between $10 and $20 per box.