Haha on the way out the door I ran into one of the medic crews who had just dropped off a patient and totally forgot to ask him. It was just one of those days, but like I said, occasionally I hear ground units, so Im guessing its either something with their handhelds or vehicle radios. I do know that some agencies are able to go to a "direct" transmission, but I have no clue how that works. I wont forget next time