On Tue, Jan 1, 2013 at 5:36 PM, Mike Waters <mikewate@gmail.com> wrote:
> This is also the impression that I have. I've read countless experiences
> over the years that indicated that trees were no worry on HF. But then this
> thread came along.
>
> I have no other antenna to compare it to, but a tall oak tree supporting my
> 160m inverted-L seems to have little (if any) effect on it.
I hope that I was clear that the sweet gums which had grown right up
into the wire were the culprit. And that the 100' loblolly antenna
tree seemed to be of little effect, other than its fortunate height
and placement for stringing the 3/8 L.
The 100' loblolly doesn't seem to bother it, presumably because the
bulk of the wood is ten feet or more away. Support rope is through
the top of the loblolly to a pulley out ten, eleven, twelve feet (hard
to measure that exactly), and then the bend insulator pulled up to the
pulley with the vertical wire slightly off vertical. The loblolly is
on the west side of the north-south driveway, and the feedline, FCP,
and tuning box on the east. Just looking at it, one would not
describe the vertical or bend as being IN the loblolly, or really next
to the tree. The bend is far enough out that the wire can't tangle in
the crown in a wind storm. But one would have said that the wire WAS
in the sweet gums (RIP), and at that, in them for a good 30-40 feet,
which was also the current max on the wire. The sweet gums grew ten
or fifteen feet in two years, something I had not paid attention to in
years past, a mistake I will not repeat.
So when someone says that they have their antenna supported by a big
oak, the devil is in the details.
If they are going up into the oak's crown and then out through the
branches, that sounds more like my situation with the sweet gums. If
they have a high branch supporting a rope that pulls a wire up
10-15-20 feet away from the trunk and then goes away from the tree
with out ever really being "in" the crown, that sounds like my
loblolly. The former seems to be a loss issue, and the latter an
antenna tree.
Or in a simple sentence for tree support, keep the vertical a moderate
distance from the trunk and avoid taking the wire through any part of
the crown.
73, Guy.
>
> On Tue, Jan 1, 2013 at 11:16 AM, Guy Olinger K2AV
> <olinger@bellsouth.net>wrote:
>
>>
>> There also remains the nagging idea that some species of tree could be a
>> lot worse than others for dielectric loss.
>>
> _______________________________________________
> Stew Perry Topband Distance Challenge coming on December 29th.
_______________________________________________
Stew Perry Topband Distance Challenge coming on December 29th.
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