Soundguy, I don't think it's likely that you would find what you're looking for. But probably the best way to try would be to contact the chief of whatever tower you're looking for, explain the project, and hope for the best. But don't be surprised if there's not a lot of enthusiasm. Not that anybody's trying to hide anything, mind you. But having your non-official, (somewhat) private conversations is not something many would be keen on. Recently we had a news station in to do some background audio and video. Supes gave folks the choice to be in or out when it happened. MANY chose not to be recorded.