RV Repair: 1993 Dutchmen Classic, tv antenna, cieling

Question

Roof Vent Knob Thing   I recently bought this travel trailer and after looking at the photos my wife sent me I was wondering what in the world this vent and knob are in the roof of it? I have attached a photo and am very curious as to what it is and what it does. Also should I worry about the wear around these two items, Any help would be great

Answer
The vent is probably the air conditioning vent.  AC comes from the cieling and heat from the floor.  The knob is for the TV antenna.  You see the ring and the crank.  The crank lifts the TV antenna off the roof.  You pull the ring down and turn it to adjust the direction of the antenna.  When you put the antenna down before you go, make sure the ring is in the proper position first.  The ring and the plastic that doesn't move at the ceiling have alignment arrows or marks on it.  Match these up and then crank down the antenna.  The damage around these indicate you may need to caulk these things because you have some leakage.  Caulk them on the roof.