Our TT is 21'.
We added the "wingman" described above. Not much over $30, and a 30 second, no tools install.
then I use antennapoint.com, from my cell or before we go.
Put in the zip where you are, and it shows all available over air stations and a compass heading to point the antenna.
Once or twice we had no useable signals, and a couple weeks ago, outside of Tampa we had about 50 channels.
The batwing lets your antenna pick up the HD channels which are now on, what used to be, UHF.
Easy, cheap, and if your not too far out, works great.
If we are, we use redbox.
Went to a place a couple months ago that hadn't heard of redbox.
Had to get a membership card for the "video store".
Haven't seen one of those in years.