> I entered a 3/8wave Inv L with a 1/4 wave counterpoise at 5' off ground
> and noticed fairly low gain of .492dbi at maximum takeoff angle. Then by
> accident I eliminated the counterpoise as I was about to add 60 radials
> but executed the model before I added them and noticed the reported gain
> rose to 2.1 dbi with no counterpoise and no radials. With the 60 radials
> of course the gain rose to 2.538 dbi.
>
> Why is there more gain with no counterpoise?
Besides what John posted, there is another effect that we should
keep in mind when modeling.
Eznec "looks at" the antenna from an extremely large distance
away. Looking at the antenna pattern from a distance large
compared to ionospheric height can give the misleading picture of
showing less useful low radiation than really exists.
My 300 ft high dipoles model to show much better FS than my
verticals at almost any wave angle, yet the exact opposite appears
to be true. The dipoles only win a very small percentage of the
time, and almost never beat my verticals distances over a few
hundred miles except at sunrise or under disturbed conditions.
73, Tom W8JI
w8ji@contesting.com
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