I am surrounded on all 4 sides by trees taller (less than 100 ft away from
the tower) and yet I am loud from my qth. I open and close bands to EU when
stations in EU say that I am the only one from the states side they can
hear. So much for tress being a factor. Take a look at other operators that
have buried their vertical antenna next to a tree or hung a dipole off of 2
trees. Lets get over this tree myth. If there is some attenuation as
claimed, its probably negligible to none that would impact anything.
Bottom line, use the HFTA software and understanding your best height.
Whether you use a Steppir or a monobander, your height at your qth based on
the terrain is the right answer.
I heard another response where someone said " A SteppIR will work wonders,
and the tower height should of little impact". Its like saying if you use
the steppir but hang it out of your window, it will do magic !!!!!. What a
ball of wax !!!
Whether it's a Steppir or a monobander, height is everything and determines
your takeoff angle from your qth. Best reading is the ARRL Antenna book and
sections on HFTA.
Good luck.
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Roger (K8RI)
Sent: Sunday, March 09, 2008 4:50 AM
To: David Gilbert
Cc: towertalk@contesting.com; Edward Sylvester
Subject: Re: [TowerTalk] ANTENNA HEIGHT
Trees, particularly in the warmer weather should show up as a *lossy*
rise in the the landscape/terrain close in (near field). How much of a
rise and how lossy is a real wild card but it could, in some cases
have a substantial effect and very little in others. That variability
would make it extremely difficult to model accurately.
Although I hear it said often, I see no real reason for a quad treating
the trees much differently than a Yagi.
Roger (K8RI)
David Gilbert wrote:
> How, pray tell, does using a quad versus a yagi have any effect on the
> attenuation of the signal after it leaves the antenna?
>
> Dave AB7E
>
>
> Edward Sylvester wrote:
>
>> My opinion is that, at treetop level, you will be ok with a Steppir, as
the take off angles will be high enough to miss the trees....But if you are
well below (50' tower below 70' trees), you will signal will suffer some
attenuation. A quad won't suffer as much due to its closed circuit design.
>>
>> I have a Steppir, too but it's in the clear. Best of luck.
>>
>> Ed NI6S
>>
>> Joe <joe@wd0m.com> wrote:
>> My 4L SteppIR is at treetop level - on a 55 foot tower. I've worked 307
>> entities in about 4 years - SWR is flat across the bands, including 40,
>> and 30M is about 1.5 or so to 1. A SteppIR will work wonders, and the
>> tower height should of little impact.
>>
>> Good luck!
>>
>>
>>
> _______________________________________________
>
>
>
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