On Fri, 18 Jan 2008 12:36:01 -0800, "Juan M."
wrote:

A problem seeking a solution.


I live in a wooded area of the Pacific Northwest with dozens of fir trees of
100 ft or more in height that make wonderful supports for high dipoles and
other wire antennas. These particular trees have very few limbs at anything
below the 60 ft level so using a crossbow or slingshot for installation is
not practical. I have been forced to employ a professional tree climber to
install the eyebolts and halyards. Using this system, the antennas can be
raised and lowered for maintenance or modification.

This system works fine until our winter storms kick in. Often, during those
storms, a tree will lose a limb or two and take the antenna down with it. I
am then left with a halyard tied to an insulator 50 ft or more above the
ground with no way to get the insulator back down short of hiring another
costly climber.

Does anyone have any solutions to this problem?



73,

John

AE7P

I can't speak for your specific situation, but here is how I handled
the similar situation.

I used either a multi-band-parallel dipole (sometimes referred to as a
fan dipole) or a 135 foot dipole fed with 300 ohm twin-lead. These
antennas were raised about 100 feet or so into trees by mason's line
which can be purchased at Walmart or most hardware or building supply
stores.

My first antenna was taken down by tree movement shortly after having
put it up. After that, I created a 'fuse' mechanism that released the
line if too much tension was placed on the antenna end.

What I did was to pull the antenna up partially until the antenna was
just above the ground. I wrapped the excess line around two nails I
used as a make-shift cleat. Then I wrapped the string around a nail
and mounted it into the bark of the tree. I did this several times a
different intervals until the antenna was raised to a maximum height
still providing for general tree movement in the wind. When an excess
wind strikes, it removes one or more of the nails lowering the antenna
without breaking the string, or if a limb hit the wire, the antenna
was low enough for me to reach the end of the line and put it back up.

disclaimer:

I didn't really trust the mason line to work as well as it did. I
typically replaced it every six months or so (as I replaced antennas
this often, mostly in experimentation or for improvements.)

While I still use it today, I don't recommend it for anyone wanting to
put up a permanent antenna and just leave it alone for more than a
year.

Buck

--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."