After the Golden Age of Radio

Development of FM and television

NBC and RCA were one of the key forces in the development of television in the 1930s and 1940s, dating back to New York City experimental station WX2BS in 1928. Before the American entry into World War II in 1941, WX2BS was officially licensed as WNBT. By the late 1940s, NBC would complement most of their owned-and-operated stations with an adjunct FM signal and a television counterpart.^{[citation needed]}
By the end of 1950, NBC's owned-and-operated stations were located in New York City (WNBC-AM-FM, changed from WEAF in 1946, and WNBT); Chicago (WMAQ-AM-FM and WNBQ); Cleveland (WTAM-AM-FM and WNBK); Washington, D.C. (WRC-AM-FM and WNBW); Los Angeles (KNBH television); Denver (KOA, purchased in 1941 and KOA-FM); and San Francisco (KNBC-AM-FM). NBC had also sought a TV sister for KNBC in San Francisco, but lost in a comparative bidding war to the San Francisco Chronicle, whose KRON-TV signed on as an NBC affiliate in 1949; that station maintained its association with the network until 2001. NBC sold the Denver outlets to a group that included one of its radio stars, Bob Hope, in 1952.^[12][13]
Many NBC radio stars gravitated to television as it became more popular in the 1950s. Toscanini made his ten television appearances on NBC between 1948 and 1952. In 1950, the network sanctioned The Big Show, a 90-minute radio variety show that harked back to radio's earliest musical variety style but with sophisticated comedy and drama and featuring stage legend Tallulah Bankhead as its host. It aimed to keep classic radio alive as television matured and to challenge CBS's Sunday night lineup—much of which had jumped there from NBC in the late 1940s, including (and especially) Jack Benny. But The Big Show's initial success didn't last despite critics' praises; the show endured only two years, with NBC said to lose a million dollars on the project.^{[citation needed]}
To reflect RCA's ownership of NBC, some of their radio and television stations call letters were changed to "RCA"-derived callsigns in October 1954. WNBC/WNBT in New York became WRCA-AM-FM-TV, WNBW television in Washington became WRC-TV, and KNBH television in Los Angeles became KRCA.^[14] By 1960, the New York flagship radio outlets reverted to WNBC-AM-FM and the television station became WNBC-TV.^[15] In 1962 KRCA in Los Angeles became KNBC (TV), while the former KNBC-AM-FM in San Francisco became KNBR-AM-FM.^[16] WNBQ television in Chicago would become WMAQ-TV in 1964.^[17]
During this period NBC Radio purchased three additional stations: WKNB in New Britain, Connecticut in late 1956; and WJAS and WJAS-FM in Pittsburgh, in 1957.^[18][19] The acquisition of WJAS was made to offset the defection of KDKA from the network several years earlier, while WKNB was a throw-in along with its sister television station. NBC had no interest in owning WKNB, a daytime-only station in the shadow of WTIC, its powerful Hartford affiliate. The network finally sold WKNB in 1960; the Pittsburgh outlets were sold in 1972.^[20][21]