Carlin officially joined WEAF as an announcer on November 23, 1923. He was on the air from 1923 to 1926, and soon became the station's program manager. When WEAF was bought by the
National Broadcasting Company, he rose to become a network executive. Carlin also became known for covering sports. He teamed up with
Graham McNamee to broadcast
college football games, including the Harvard-Yale game in 1925; an early example of chain broadcasting, the game was carried by 13 stations. Carlin and McNamee also collaborated to announce the
1926,
1927 and
1928 World Series, as well as
boxing matches, including
The Long Count Fight between Jack Dempsey and Gene Tunney in 1927. On some occasions, Carlin covered college football games without McNamee. In addition, Carlin covered news and current events, including the
1924 Democratic National Convention and a 1927 reception in New York to honor aviator
Charles Lindbergh. He later announced several musical variety programs, including
The Atwater Kent Hour,
The Goodrich Hour and
The Palmolive Hour. In 1927, Carlin became convinced that NBC programs needed a definitive and consistent ending, to help affiliates know when it was okay to break away from the network for commercials or local announcements. Many stations were already using chimes, gongs or other sounds to signal that a program was over; Carlin liked the idea of chimes, and working with Oscar B. Hanson, NBC's director of engineering and a former AT&T engineer, as well as Earnest la Prada, an NBC orchestra leader, they created what became the famous 3 tones known as the
NBC Chimes. Carlin subsequently rose to NBC's Eastern program manager and then program manager of the entire NBC Red network; he was subsequently moved over to NBC Blue, where he held a similar post. In addition, during the mid-to-late 1930s, he was the executive in charge of NBC's sustaining programs division. During his time as a program manager at NBC, he was credited with introducing a number of soon-to-be famous performers to the radio audience, including
Dinah Shore, the
Ink Spots, and
Dorothy Lamour. After NBC was ordered by the FCC to divest from NBC Blue, Carlin left NBC in mid-November 1944. He soon joined the
Mutual Broadcasting System, where he became the network's vice president in charge of programs. In November 1948, nearly forty of his peers, including radio executives, journalists, and former announcers, honored him with a dinner and a tribute on his 25th anniversary in radio. Carlin continued working as Mutual's vice president of programming until March 1949, when he unexpectedly resigned. For a while, he worked as a radio consultant, before getting into television, where he also worked as a consultant. ==Television==