HF Verticals: interaction with metal fencing?
Dave Palmer
Hi all,
I need to construct a fence around the perimeter of my backyard
which measures about 150 feet by 100 feet. Right in the middle of
this area is a Butternut HF6V HF vertical antenna with 50 buried
radials.. My question is: should I go for a wooden cedar fence, or,
a fence made of wood posts, but with steel mesh all around?
(We need to keep the 1-year old triplets IN, but I still want the
RF to get OUT.). The all wood fence would be pretty invisible to RF,
but if we need to choose the metal fence (at nearest it would be 50 feet
from the HF6V) perhaps grounding it to the radial system at several points
would actually be beneficial??? Or is this something to avoid at all costs?
(Yup, I know it is steel so not the greatest conductor of RF...)
If anyone has ideas on this or experience with fencing and radial systems,
please post a comment or reply to me directly at 73357...@compuserve.com.
Many many thanks!!!!
73, Dave Palmer, N6KL/0, Boulder Colorado
Bill Brannick
On 3 Aug 96 22:36:56 GMT, 73357...@compuserve.COM (Dave Palmer)
wrote:
>Hi all,
>I need to construct a fence around the perimeter of my backyard
>which measures about 150 feet by 100 feet.
Lots of varibles in these situations.. but I can say that the
distances you suggest are far greater then those I have had with my
chain link fence and my GAP vertical ( ground mounted). I am about 18
feet from the fence and I don't think I am suffering from any
interaction. I would test the idea of tying in the fence to your
radial system before spending the bucks to make it permanent, but it
sure could help (IMHO)
Bill Brannick | Bill_B...@akaMail.com
" Life is just one damned thing after another "
-- Frank Ward O'Malley
Alexander Vrenios
In article <960803223656_73...@compuserve.com>,
Dave Palmer <73357...@compuserve.COM> wrote:
>Hi all,
>I need to construct a fence around the perimeter of my backyard
>this area is a Butternut HF6V HF vertical antenna with 50 buried
>radials.. My question is: should I go for a wooden cedar fence, or,
>a fence made of wood posts, but with steel mesh all around?
>
>(We need to keep the 1-year old triplets IN, but I still want the
Dave, I had a split cedar fence with wire mesh inside the rails
to keep my dog in. The yard was slightly bigger, about 180' on each
side, but the HF6V was in the center, ground mounted, just like yours.
I had about twelve burried radials, odd lengths to their respective
ends of runs, based on driveways, sheds, house edges, etc.
Bottom line: I never knew the fence was there. I suspect that the
radiation angle (which I certainly had no exact knowledge of!) was
enough to push the toroid higher than the 3 or 4 feet necessary to
clear it. I believe the wire mesh was "sheep" style, with 4x6" holes
in a rectangular pattern. (Replacing broken posts was a challenge,
but the dog loved the freedom.) Gook luck!
Regards,
Alex Vrenios Distributed Algorithms
Vre...@asu.edu _._ _.._ ____. .. Research Lab
Steve Ellington
Of course the metal fence will effect the radiation pattern. Considering
that your vertical has a very low take off angle, 50ft away is hardly
enough to avoid negative effects. Don't pay any attention to testimonies
like " I have a fence and still work dx".
Fact is, unless you have means to measure the before and after results,
you will never know what happened. If you put up the fence, you will
continue working stations as before and never really be able to tell if
you lost 5db.
Since this is a concern, I would put up a wooden fence and forget using
any metal otherwise, after reading this, you will never sleep. 73
--
Steve Ellington N4...@IGLOU.COM Louisville, Ky
Cecil Moore
n4...@iglou.com (Steve Ellington) wrote:
>Since this is a concern, I would put up a wooden fence and forget using
>any metal otherwise, after reading this, you will never sleep. 73
Of course, the wooden fence must be painted with a waterproof,
non-conductive paint or else he will never sleep. :-)
73, Cecil, W6RCA, OOTC
mike_...@ziplog.com
In <960803223656_73...@CompuServe.COM>, 73357...@compuserve.COM (Dave Palmer) writes:
>Hi all,
>I need to construct a fence around the perimeter of my backyard
>which measures about 150 feet by 100 feet. Right in the middle of
>this area is a Butternut HF6V HF vertical antenna with 50 buried
>radials.. My question is: should I go for a wooden cedar fence, or,
>a fence made of wood posts, but with steel mesh all around?
>
>(We need to keep the 1-year old triplets IN, but I still want the
>but if we need to choose the metal fence (at nearest it would be 50 feet
>from the HF6V) perhaps grounding it to the radial system at several points
>would actually be beneficial??? Or is this something to avoid at all costs?
>(Yup, I know it is steel so not the greatest conductor of RF...)
>
>If anyone has ideas on this or experience with fencing and radial systems,
>please post a comment or reply to me directly at 73357...@compuserve.com.
>
>Many many thanks!!!!
>73, Dave Palmer, N6KL/0, Boulder Colorado
>
Of course it affects it. Worse, the effects will be different depending on the
band you are working.
How much effect? You could model it, but that's work. You can measure
it after you have spent the money. That's not so useful.
Like many other things in life, we probably outhg to do things on the basis of
risk for gain. I betcha this is one of them! You have sonething to risk for
chunking up the metal fence and little to risk, RF wise from the wooden
alternative. You have something to risk, perhaps, from your pocket book's
view, between wood and metal. Bottom line, if you can afford the wood,
you do it since the risk is there but unknown as to actuall effect! Right?
Aside from that, your XYL/YL or any other architecturally minded party that
gets to look at your place, will probably think, "My what a neat place",
with a neat wood fence and not think so highly of your tastes otherwise.
Unless, of course, that person were the world's greates industrialist or
thinks like one!
:)
Mike W5WQN
Mike Willis
Dave Palmer wrote:
>
> Hi all,
> I need to construct a fence around the perimeter of my backyard
> which measures about 150 feet by 100 feet.
If I were you I would insulate the metal fence from ground, make
sure it had good contacts all round, and load it up as a horizontal
loop. It will be 500ft long and possibly good for 160m. Call it an
electric fence and keep the triplets off it while transmitting.
Bill Harwood
Dave Palmer wrote:
>
> Hi all,
> I need to construct a fence around the perimeter of my backyard
> this area is a Butternut HF6V HF vertical antenna with 50 buried
> radials.. My question is: should I go for a wooden cedar fence, or,
> a fence made of wood posts, but with steel mesh all around?
>
> (We need to keep the 1-year old triplets IN, but I still want the
> RF to get OUT.). The all wood fence would be pretty invisible to RF,
> but if we need to choose the metal fence (at nearest it would be 50 feet
> from the HF6V) perhaps grounding it to the radial system at several points
> would actually be beneficial??? Or is this something to avoid at all costs?
> (Yup, I know it is steel so not the greatest conductor of RF...)
>
> If anyone has ideas on this or experience with fencing and radial systems,
> please post a comment or reply to me directly at 73357...@compuserve.com.
>
> Many many thanks!!!!
> 73, Dave Palmer, N6KL/0, Boulder Colorado
If you can get a few feet of mast underneith the Buternut and wire the
fence into the ground system and make sure you have continuity you will
get outstanding performance. Get the base of the buternut up about 10
feet, use the twin lead radial kit (or make them yourself) and wire the
ground side to the fence. Watch what happens on 80 and 40. Add the
160 kit and get superior performance. The chain link fence makes an
excellent counterpoise even over poor earth. I did this out here in the
Mojave desert and had tremendous performance.
Bill Harwood AB6DY
Patrick Tice
Dave,
I don't think it will matter if you choose the steel fence. At a
distance of 50' the effects will be negligible (unless it's 20 feet
high!)
It seems to me (a guy with kids in the yard) that you can't elevate
the antenna per Bill's suggestion and keep the resulting elevated
radial system intact -- the kids will soon level it with balls,
sticks, flying objects, etc., etc. -- you know what I mean! Stick
with the current installation, which will not only tune better, but be
easier to maintain. Elevated systems do work well, but with 50
radials, you have a superior system already.
My HF9V-X works great... ground-mounted! I protected it with a small
cedar fence around the base. The coils have taken a cuppla hits by
errant balls, but whatcha gonna do?
Don't worry about the fence... it's too far away to be a concern.
--73--
Patrick Tice, WA0TDA
(Butternut co-founder!)