Hi Richard,
While I do not have experience with pine trees (they don't grow
here in Oregon) I do have many years of experience with coniferous trees
and antennas. Don't lay your wire across the tops of them as suggested
you will only be frustrated by how little time they will spend in the
air. You may get one month but that would be luck. Any breeze coming
along will knock them down. My trees ( a mix of hemlock, Douglas fir,
and western redcedar) block propagation when they are wet but mostly at
higher frequencies. 70 centimeters is the most highly effected. On a
typically foggy day you need to find a hole in the trees for a hand held
to work at all. However, at the lower frequencies of HF you won't
experience much attenuation at all. Since you're running a wire at
right angles to the trunks there won't be much effect from them. I have
one inverted V and one flat top doublet. 80 meters is limited to upper
California to lower British Columbia and then out into the desert areas
of the northern Great Basin. The biggest problem to propagation is
having the Pacific Ocean out to my west. There are not a lot of 80
meter operators there.
Another problem with coniferous trees is snow loading. This is how
I lose my antennas. After our typically wet snow falls the limbs can
lower by as much as forty feet. The normal failure mode is for the
antenna lines to part from their central connection when the drooping
limbs capture the wires and pull them loose. I then use my F-250 to
pull down the lines holding up the remaining bits of the antenna and
rebuild it. I need to use the truck since the lines are quickly
attached to the trees by growth or from pitch. Limbs falling can also
be a problem but this only happens during the larger storms. Get your
support lines as close as you can to the trunk of the tree; any further
out and the trees will shed the lines quickly letting you practice
putting them back up again.
By the way, fir trees don't become mature until they are around 300
years old. By then they are normally one hundred feet tall if they have
not been pruned by storms. I have a few of these older trees around my
property but most of them are new growth of less than 60 years of age.
While my normal noise floor is S1 it drops even further when there is a
foot of snow on the trees. But then I am also losing a fair amount of
signal to all that supported water. My antennas use insulated wire which
helps them from shorting to ground but when the antennas carry an inch
or two of snow the signal is attenuated. The first breeze coming by
normally clears the antenna wires and my received signal strength jumps
by an S unit or two.
Good luck,
Kevin. KD5ONS
On 6/25/2014 11:12 AM, Rstafford12 wrote:
I realize this is another somewhat not on topic post, but it is in regards to
my KX1 and KX3. I have a mature pine forest; 60 -70 foot trees. How compromised
would an EDZ be hung 45 feet up about four rows of trees in from the perimeter?
No branches or needles inside the forest until 50 feet up. Richard KD0NPM
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