I start reading about acoustic analogy.
I found that: "Over long distances, the atmosphere can cause the
polarization of a radio wave to fluctuate, so the distinction between
horizontal and vertical becomes less significant." From:
http://whatis.techtarget.com/definit...843762,00.html

The my question a
1. What means "long distances" in km (or miles),
2. What is the best orientation of the antenna for long distances.
S*