Expect the first shot in the war on analog TV tonight at 6:30 p.m.

When he launched the “war on terror,” President Bush got low marks for asking U.S. citizens not to sacrifice and instead to go shopping. Now as it nears its end, the Bush administration is revising that call to duty: Go shopping for a digital TV, or at least a converter box.

The nationwide conversion to digital television broadcasting, set for Feb. 17, will free up bandwith for those responding to emergencies like the 9/11 terrorist attacks, according to Secretary of Commerce Carlos Gutierrez, whose agency is spearheading the effort. The first test of the new system is tonight at 6:30 p.m., when TV screens in need of conversion will turn red and carry a message about what their owners can do about it. (Televisions already receiving digital signals will show a green screen.)

A lot of TVs in this blue state will be glowing red — Minnesotans, bless ‘em, are said to get their TV for free via over-the-air analog signals in greater numbers than residents in all but two other states. Because cable and satellite TV subscribers won’t be affected by the conversion, Comcast expects a windfall of 2 million new customers for such services, and retailers of TVs and converter boxes anticipate a sizable bump in business as well. Read about a federal coupon program for a new converter box below.

Television viewers who don’t have a digital TV and don’t pay for cable or satellite TV service will have to buy a converter box. Through Dec. 31, the federal government is accepting applications for $40-off coupon (limit of two per household) that will make a $50–$70 converter box more affordable. After New Year’s Day they’ll be available only while supplies last from the National Television and Information Administration, an agency of the U.S. Dept. of Commerce. (Didn’t know there was a National Television and Information Administration? Then you’ve just been administered some national television information!)