I own a Raytheon R41X radar. It's a 4kw, open array. Everything works good and seems just fine when I'm under way. But when sitting in the slip with the radar on but without the engine running I hear a tiny "click" in the antenna unit as it goes around. It does it in the same place everytime it makes a revolution. I wonder what this is and if something is wrong with it. Old but not many hours on it.