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Old November 6th 07, 11:54 PM posted to rec.radio.amateur.antenna
[email protected] nm5k@wt.net is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 757
Default 80m Vertical over lossy soil

On Nov 6, 4:27 pm, (Rick) wrote:

So my conclusion is that even though the vertical might have the low angle
pattern, the losses in the soil do not allow the advantages to be realized.
Phased arrays of similar antennas over lossy soil may show the nice pattern
and f/b but the absolute value of gain expected may not be realized.

73 Rick K2XT


I saw pretty much the same thing. If you want truly top notch
performance
ground mounted, you have to lay out the wire. Well, unless you are at
the beach or something.. :/
I ran mostly 40m using full size verticals, and even with 32 full
length radials,
I saw mediocre results at best. And I'm on a high rated ground as far
as
conductivity.
When I elevated the antenna to 36 ft at the base is when I finally saw
decent
performance.
Of course, it's not going to be easy to run a full size elevated
ground plane
on 80m..
The only way you are going to see the performance you should is by
coughing up more wire.
But according to some I read, 60 will do the trick rather than having
to do
the full blown 120.. Not a whole lot of difference between the two in
theory.
Even elevated at 1/8 wave, a ground plane needs appx sixty radials to
equal
a ground plane at 1/2 wave , using four radials.
And about 120 may well be needed if you really want to equal the
losses of
the high ground plane.
Ground clutter can be another problem, although usually not huge.
But, it's
just another reason why I prefer an elevated vertical if at all
possible.
As far as the modeling, I have to adjust the programs to "very good"
ground
to have it equal what I see in the real world at this QTH.
If they are set to default "average" ground, the verticals get
shortchanged.
But on the other hand, maybe that just tells me the ground here is
better
than average, which actually it is... :/ I'm on the gulf coast, and
most of
the area rates a "30" on the conductivity maps.
Thats no sure thing though.. Even though the ground is decent here, I
never had better than mediocre results using a ground mounted vertical
with 32 full length radials. I had very good results with the 36 ft
high ground
plane though. Was like day and night..
MK