WEEI format change

[Kevin Vahey]

Sox were on HDH from 1947 to the end of the 75 regular season when
they moved to WMEX for the playoffs. Yawkey was angry they had
switched to a soft Top 40 format and MEX agreed to switch to MOR and
got the team.

The team had been with WNAC or WAAB before then. Not sure when AAB
moved to Worcester.

http://sonsofsamhorn.net/wiki/index.php/Category:Red_Sox_Broadcasters