When designing
these antennas, great care was taken with the radiation
patterns, both in the 360 degree direction and in the
elevation plane. (See patterns below).
Many competitive omni-directional antennas considerably
over claim their gain figures. Very often the radiation
pattern is not smoothly omni but has shallow nulls in
it. In the elevation direction a feature known as "frequency
scan" occurs. This is where different frequencies
reach maximum gain at different elevation angles. From
the subscribers point of view this shows itself by having
different gain figures at one end of the band as against
the other. All this results in poor system performance
and high bit error rates.
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ELECTRICAL
SPECIFICATIONS 
