On Sat, 14 May 2005 18:53:06 -0400, "CryptWolf"
wrote in
1116111148.11781a37a6d5a6e2b697012478f45470@teran ews::

Since the radiation pattern is reduced at higher altitudes, there is less
chance
of frequency congestion and receiving a signal you don't want.
With limited frequencies available, you have to depend on other
limits to prevent unwanted reception of other signals.

The radiation pattern also puts more energy where it was needed, as
that energy that would be radiated upward is directed laterally
instead.