That transmitter looks like it was heavily modified. Perhaps to accept external battery and maybe connect to a different antenna. They drain 8x AA batteries in few hours and the antenna gives you light shock so that might be the reason why it was modified. Also the original board on yours seem to be re-soldered so who knows what's happening there. I hope someone here can id what those modifications are and give you a solution. This is how an original FP-T2F looks like, you can see that the original battery tray fills the whole space underneath the board and there are no outlets.