In 1950, WFAA switched its primary affiliation to NBC, and also affiliated with ABC on a secondary basis. DuMont shut down in 1955, amid various issues that arose from its relations with Paramount that hamstrung it from expansion. Although it had been apparent from the start that Dallas and Fort Worth (which Arbitron originally designated as separate media markets) were going to be collapsed into a single television market due to their close proximity, "Fort Worth Star-Telegram" owner Amon G. Carter—who founded WBAP-TV through his company, Carter Publications—did not care whether residents in Dallas could view that station; WFAA affiliated with NBC under a time share arrangement with WBAP-TV to expand coverage of the network's programming to areas of central and eastern Dallas County that only received rimshot coverage of the Channel 5 signal.