Sorry Hem, I'm with Prodigy on this one.
You use a signal booster/amplifier and you boost the noise as well.
If your out of range, you just get a *rap signal.
You'll have to do some homework before you leave home, and work out the coverage of the area your going into.
The old style yagi type aerials still work, you just have to get one for the right frequency/band.
The longer, and more elements, the more amplification you get.
Then you have to work out if type of TV signal is vertical or horizontal oriented.
Obviously the higher you can get the aerial/antenna the better.