The station's call letters were later modified to WTMJ-TV (referencing "The Milwaukee Journal"), which first signed on the air on December 3, 1947, originally broadcasting on VHF channel 3. In addition to being the first commercial television station to sign on the air in Wisconsin, the fourth such station to sign on in the Midwestern United States and the 15th to launch in the United States, WTMJ was also the first station located outside of the Eastern Time Zone to be affiliated with a major broadcast television network. At the time it began operations, there were only 500 television sets in Milwaukee; that number would jump to 2,050 by the following April. The existence of television sets in Milwaukee before WTMJ-TV even debuted was because of the fact that the city is close enough to Chicago that television stations from that market could be and still are viewable in Milwaukee; therefore, residents in southeastern Wisconsin had access to WBKB-TV (now WBBM-TV), which signed on from Chicago in 1946 as the first commercially licensed television station outside of the Eastern Time Zone.