Isn't there a Red Sox affiliation with WJAB and WLOB in Portland, Maine?
Yes. And because Atlantic Coast's WJJB/WJJB-FM/WJAE/WLOB/WLOB-FM together don't hit the southern areas of the market, they are also heard on 1400 WVAE in Biddeford, half of "the Bay"... although that deal dates to when the station was WIDE.
But we've seen how Entercom has dealt with the existing Red Sox rights deals in Worcester with WTAG, Springfield with WHYN (AM), and Providence with WPRO (AM). While the Sox may be on a competing station at first and the WEEI "affiliate" will be forced to air Fox Sports for the interim, you know where the rights are going when the contract is up.
For the heck of it, does anyone know when the Sox rights in Portland expire for Portland?
You're correct that there could be some problems with the Red Sox if 93.9 were to simulcast WEEI. There are sometimes ways to work around that, though. I don't know how the Red Sox handle their rights as I've never dealt with them, but I am somewhat familiar with how the St. Louis Cardinals do, or at least did, things as I've worked for several stations that have carried their games in the past. The Cardinals actually had problems with too many affiliates well before the move to 550 KTRS last year. The games were allowed to air on overlapping signals so long as no station infringed upon another's sales territory. So, when I worked for KFRU in Columbia, MO, we could air the games despite some significant overlapping with KKCA 100.5 (Fulton, MO), KWOS 950 (Jefferson City, MO) and KRES 104.7 (Moberly, MO). The overlap was just fine so long as we only sold the games in Boone County. In cases of game conflict with the University of Missouri, we also could only bump the Cardinals to a Columbia licensed station if I'm remembering the contact correctly. KKCA, KWOS and KRES had to follow similar rules as none of them could sell the Cards in Boone County. There's also a similar situation in Springfield, where KTXR 101.3 carries the Cardinals and KJEL, a 100,000 flamethrower just 40 miles away, also airs them. So long as they don't infringe on each other's territories, it's fine. I believe it was KTJJ that lost the Cardinals for a few years in the 80's for infringing on KMOX's territory by selling the games in Jefferson County. If the Sox had deals like this, it would be a lot easier for Entercom to work around the overlap. The New Hampshire stations, for example, would be a non-factor as their territory would almost certainly be limited to a county or two in New Hampshire.
Interesting stuff. I can't imagine that the New Hampshire stations really play into advertising, but they are necessary for fans in southern York County to hear the games when they aren't near a TV.