WILMINGTON, N.C. — With the flick of an 8-foot switch at midday Monday, this Southern city became the first market in the U.S. to make the change to digital-only broadcasting.

The switch wasn't really connected to anything, but it did serve as a centerpiece for a downtown ceremony at noon marking the moment commercial TV broadcasters voluntarily turned off their old-fashioned, inefficient analog signals.

Wilmington volunteered to be a canary in a digital coal mine — a test market for the national conversion to digital broadcasting.

The rest of the nation's full-power television stations won't be converting until Feb. 17, 2009, a date set by Congress.

"This switch is the biggest change in television since it went from black and white to color back in the 1950s," Federal Communications Commission Chairman Kevin Martin told the ceremony at historic Thalian Hall in downtown Wilmington.

Wilmington, tucked between the Cape Fear River and the Atlantic Ocean, is the 135th largest television market in the U.S. with about 180,000 television households, according to Nielsen.

In February, Nielsen estimated there were more than 13 million households in the U.S. with television sets that can only receive analog broadcasts. Only about 8 percent of households in Wilmington are in that category, fewer than the national average.

Viewers who receive programming through an antenna and do not own newer-model digital TV sets by the time of the changeover must buy a converter box. The government is providing two $40 coupons per household to help defray the cost, which is usually about $60. Viewers who subscribe to a cable or satellite service won't be affected.