The setting: city to the west, mountains to the east. For 2 meter
transmissions, should one feel bad that half the coverage area of ones
vertical antenna is wasted on unpopulated mountains, or might the
mountains reflect most of the signal anyway, especially if right
east of us is an idealized vertical mountain wall? Thus no hurry to
upgrade to a yagi?

My guess - the mountains reflect some of the signal, but in a rather
unpredictable manner and with much of the energy being reflected
upwards.

The mountain reflections might help fill in a few gaps in your
coverage pattern. However, the reflections are likely to _hurt_
coverage in some areas, due to multipath interference with the direct
(non-reflected) signal. You might find that your signal suffers from
a greater amount of picket-fencing due to multipath, than it would if
the mountains were not present or if the antenna's pattern didn't
include the mountains. The more vertical (and the more reflective)
the mountain wall is, the stronger the reflections, and perhaps the
more pronounced the picket-fencing.

It might well be worth your while to experiment with a simple
somewhat-directional antenna. A single reflector, located perhaps .1
to .2 wavelengths on the mountainside side (sorry :-) of your current
vertical, cut to perhaps 5% longer than a half-wavelength, could be
used to shape your antenna's pattern into something vaguely cardioid.
This would send your transmit energy (and your receive sensitivity)
where it will do you the most good. Play around with the antenna-to-
reflector spacing and see what it does to your pattern.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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