I listen to WMBR which is MIT's radio station. They used to be WTBS for its parent organization The Technology Broadcasting System, but in the early days of cable TV Ted Turner wanted those letters so he offered them a big chunk of money to let him have them and they put it all into transmission power so they went from a station you could only get near the campus to covering all of Boston/Cambridge and pretty well out to the suburbs.

The new letters are for Walker Memorial Basement Radio since that's where the station is housed in the Walker Memorial building on the campus.