All,
I too live in the PNW, an area with tall Douglas Fir trees. I am
blessed relatively large area in which to experiment: a grove of fir trees,
a treed area adjacent to a series of single family homes, and the shore of a
peninsula that juts out into a fresh water lake. I have recently run a
series of A Vs B direct comparison tests with vertical GP's suspended in a
grove of trees compared to free standing verticals mounted on the shore of a
large fresh water lake. The bands of interest were 80 and 40 meters LP. My
conclusion is that on those bands, there is no detectable difference between
the tree mounted and the free standing(out of the trees) antennas for LP on
those bands. The presence of homes has a definite negative impact on
vertical antenna performance. This particular difference is quite
noticeable.
All of my tree mounted vertical antennas are suspended on catinaries
that run between trees. This way, the vertical wire is spaced 30' to 50'
away from the tree trunk in a relatively open space. I wouldn't worry too
about the proximity of tree trunks to verticals if at least a little spacing
is possible.
Regards,
John Petrich, W7FU
----- Original Message -----
From: "Tom Osborne" <w7why@harborside.com>
To: "TowerTalk" <towertalk@contesting.com>
Sent: Tuesday, May 21, 2002 6:11 PM
Subject: Re: [Towertalk] pine tree verticals
>
>
>
> > On Mon, 20 May 2002, Jim White wrote:
> >
> > will be putting up a vertical antenna for receiving this
> >weekend....on 40 and 80 meters - one location is thick with pine >trees
taller than the vertical - should I even think about >problems at this low a
frequency?
>
> Hi Jim
>
> Here in Oregon, there aren't many places you can look and not see
> a tree (thank God). I have all sorts of antennas buried in them,
> verticals, inverted "V's", dipoles, beams, etc. Have never found
> anything detrimental caused to them by trees. All I know is
> trees make a GREAT place to hang antennas.
> I once had a cage vertical in a tree here--4 wires up the tree
> and a top hat in the limbs. Worked like gangbusters on 80. 73
> Tom W7WHY
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