This is the antenna I use. Channel Master 4221HD Mid-range outdoor rooftop HDTV antenna at Crutchfield.com
It is the same basic antenna as the coat hanger antenna but it has a reflector which makes it more directional. The range is about 45 miles with no amplifier. It packs into a box which is 2'X3' about 3" tall which I just lay on the upper bed of the 5th wheel in transit. I mount it to a pool cleaning pole which is mounted to a bracket attached to the camper.
The coat hanger antenna is good if you in the center of several transmitters. The Channel Master is better if you have several transmitters in the same direction. Channel Master also makes a two detector antenna which is half the size 18"X 24" but it cost more.
If you go to TV Fool
and plot your camping location it will tell you where the TV transmitters are located in respect to your camp site. This really helps in aiming your antenna.
I don't have any connection with Crutchfields but they have been really great to deal with.