Tom Larson, the legendary Boston sportscaster who covered the Bruins and Red Sox, died Wednesday of complications from cancer, his son told The Boston Globe. He was 84. Starting as Channel 38’s public affairs director in 1969, Larson garnered a reputation as a regular Red Sox and Bruins programming contributor before, in the 80s, moving to WHDH radio as its sports director. In 1981, he vowed he wouldn’t shave his beard until the Bruins won the Stanley Cup again. “I had no idea it was going to be 30 years,” he said after the Bruins’ next championship in 2011, well after his retirement. Larson became a staple of Boston sportscasting, with Boston Magazine in 1983 dubbing him as the city’s “Best Sportscaster.” In 1986 he joined NESN, hosting Red Sox and Bruins programming.