If your television set erupts into wavy color lines and voice-of-doom instructions to call a toll-free number Monday, don't worry -- it's not a nuclear attack or a space-alien invasion. It just means your set isn't ready for the switch to digital broadcasting signals scheduled for next year.
Preparing for the changeover, South Florida TV stations will move their programming to the new digital signal twice, for two minutes apiece, on Monday -- at 6:20 a.m. and 6:20 p.m. Viewers whose sets are digital-ready shouldn't notice a thing.
Meanwhile, the analog signal -- the one that will be shut down for good on Feb. 17 -- will carry only the warning message that directs viewers to a toll-free telephone number (1-877-388-5353) and a website (www.dtv.gov) for help.
Viewers who watch television using a cable box or a satellite dish (as about 90 percent of Americans do) shouldn't have to do anything to prepare for the switch to digital. But televisions connected only to antennas -- whether on the roof or the set itself -- must be hooked to digital converter to continue receiving signals after Feb. 17.