I have gotten through a lot of the Brotherhood of Steel quests at the police station in Cambridge. They are getting quite repetitive now. Go and fetch some device from some location and bring it back. Do these quests ever have an ending or do they just keep repeating forever?
After going through many of these quests myself, I can confirm that this is an endless quest line. You can keep collecting more and more quests until you progress far enough in the main story to determine how the story plays out with the brotherhood.
It does suck that there is no ultimate reward for completing these quests, but it is a really good way to quickly level up and get a lot of easy caps. Take advantage of these quests while they last.