Ray,
If we are talking about horizontal polarized antennas
You cant be high enough on 80m/160m
And there is no needs to think a lot about effects of fresnel zone on 160/80
Not even with 300m high tower
Of course if there are no uphills around you .....but so far understand you
That location is free with slight slope around
In my mind its important to have flat or homogeny slope in desired direction
Effect of excellent soil is not so critical for ground reflection if you are
using horizontal polarized antennas!
On other side for vertical antennas soil is more important but directly under
the antennas and in closed flied!
In simple words if you can have antenna in saltwater or very close to it put it
in
If you are far away from good soil with vertical (even 1 wavelength) you will
need standard numbers of radials under the antenna!
Iif you are on flat terrain with excellent soil you will need very large
antenna on high tower to outperform 4SQ on 80m !
On 160m is non sense to even try something else than vertical or vertical arrays
73s
Braco
E77DX
--
Emir Memic
EMS SOLUTIONS
Köhlergasse 12/3
1180 Wien
+4369919227041
emir.memic@emssolutions.at
-----Ursprüngliche Nachricht-----
Von: Topband <topband-bounces@contesting.com> Im Auftrag von Ray Higgins
Gesendet: Donnerstag, 18. April 2019 16:49
An: topband@contesting.com
Betreff: Topband: Fresnel Zone
I have two questions about fresnel zone.
I just purchased 22.5/ac near the ocean near Machiasport, ME. This is in the
Northeast corner of Maine about 30 miles south of Eastport and a Lubec. This is
going to be my personal Remote Contest station! I plan to be contesting from
this new qth starting in 2020 but will be QRV by mid 2019 for testing.
This qth is anywhere between 1-3 miles from the ocean or the bay, it sits on a
high plateau 150’ asl thats slopes in all directions to saltwater (peninsula)
except N/NW. The property has a saltwater river and marsh that runs the
perimeter from south to north favoring the NE direction, the marsh is only
50-100' wide and 1500-2000’ away from the property. The land has a gradual
slope to the marsh.
My questions:
1.) Is the saltwater river bed/marsh wide enough to be an effective field in
the Fresnal Zone?
2.) What is the wavelengths needed to be within the Fresnal zone of a
river/marsh compared to an ocean?
In this photo album (last pic) I have outlined the river saltwater marsh and
property boundry from a google earth shot.
https://photos.app.goo.gl/ui79t2jFo95b29et6
I’m only concerned about 80 and 160m in the Fresnal Zone.
Any input would be welcomed.
Thanks,
Ray W2RE
Sent from my iPhone
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