[Elecraft] Windom Antennas

Fri Jun 6 21:49:02 2003

The point is NOT that a vertical CAN'T work. Never said that. Not
against verticals. Never said that. I HAVE had some adverse
experiences.

Just said that if the details aren't taken care of, beyond just
propping it up and hooking up coax, there are a ton of possible losses
to get hooked into, and most of the bought vertical installations I've
seen don't deal with them all.

As I stated earlier, my 14AVQ Hygain trap vertical up on top of all
those copper roofs in Wash DC was a killer antenna.

When it moved with me to my little 1/4 acre suburban house, it turned
into a dud even though the SWR was a perfect 1:1. A Windom 20 ft high
beat the pants off it, to anywhere, on any band 40-10, all the time.
TODAY I know why.

Back then I didn't understand much of anything. If I'd known better I
would have put down radials just under the grass and probably had MUCH
better luck.

73, Guy.

----- Original Message ----- 
From: "George, W5YR" <[email protected]>
To: "Guy Olinger, K2AV" <[email protected]>; "Bob Lewis AA4PB"
<[email protected]>; "Elecraft" <[email protected]>
Sent: Friday, June 06, 2003 6:36 PM
Subject: Re: [Elecraft] Windom Antennas

> Guy, you must have had some adverse experiences with verticals
somewhere
> along the line . . .
>
> I use the Butternut HF-9V, ground mounted over a field of 18 radials
each 25
> ft long. The antenna resonates per the CIA-HF impedance instrument
in each
> of the 9 bands. It loads well with very low line SWR. Based upon the
SWR,
> impedance measurements and the design of the radial field, the total
ground
> loss is likely no greater than 3 dB and is possibly less. This is in
a
> typical backyard with trees, power pole and lines nearby, etc.
>
> The key thing about the vertical is that in competition with a pair
of
> 20-meter extended double zepps, mounted at 38 ft and at 90 deg,  and
a low
> 80-meter horizontal full-wave loop, the vertical many times produces
better
> signals than any of the other wire antennas.
>
> I participate in the QRP-L Fox Hunts and most QRP operating events
and fully
> a third of  the time, the most difficult contacts are made with the
> vertical.
>
> I find that it is noisier than the wires but not exceptionally so.
Late at
> night when 20 meters is largely asleep, it is interesting to monitor
14,100
> and listen to the beacon stations and try the various antennas. You
would be
> surprised at how often the vertical returns the best signal, even
from
> locations favored by the patterns of the EDZs.
>
> All your points are technically valid, and taken in summation would
persuade
> anyone that using a vertical is heresy. Nonetheless, with proper
> installation and attention to the points you mentioned, a vertical -
even a
> "compromise" multi-band vertical - can provide superior performance
when
> conditions favor.
>
> You might enjoy reading of the research done in the 70's with
shortened
> verticals by Jerry Sevick, W2FMI. His work was published in QST at
the time
> and is reprinted in appendices in "Building and Using Baluns and
Ununs."
>
>  Jerry provides quite detailed loss measurements and the like for
various
> radial configurations, etc. I might add that Dr. Sevick, formerly a
> scientist at Bell Labs, knows what he is doing, and his work can be
relied
> upon for accuracy.
>
> Neither his work nor my experience and measurements can support your
dire
> predictions of 6-10 dB loss with a vertical for the reasons you
enumerate.
>
> 73/72, George
> Amateur Radio W5YR -  the Yellow Rose of Texas
> Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
> "In the 57th year and it just keeps getting better!"
> <mailto:[email protected]>
>
>
>
>
>
> ----- Original Message -----
> From: "Guy Olinger, K2AV" <[email protected]>
> To: "Bob Lewis AA4PB" <[email protected]>; "Elecraft"
> <[email protected]>
> Sent: Friday, June 06, 2003 5:00 PM
> Subject: Re: [Elecraft] Windom Antennas
>
>
> > I agree with your statement about poor installation. Unfortunately
it's
> quite WORSE than that. Lack of a proper ground connection is only
loss
> factor #1. Note that poor series ground conductivity at a ground
located
> feedpoint does not apply to a series of "vertical" antennas that
have feed
> points up the antenna. But the rest below DO.
> >
> > Loss factor #2:
> >
> > An antenna will initially radiate about half its power below the
horizon.
> Horizontally polarized energy will essentially bounce at some angle,
at full
> strength.
> >
> > Vertically polarized energy will usually be absorbed instead of
bouncing.
> UNLESS the ground media at the bounce is salt water or laced with
> conductors, like extensive dense buried radials. Both of those are
rare in
> the typical installation, since the vertical was chosen because of
LACK of
> good supports for horizontal antennas, or limited space, which means
limited
> space to place radials, if even practically possible.
> >
> > Loss factor #3:
> >
> > A vertical antenna has a lot of flux directly underneath. It
penetrates
> the ground to a surprising degree. If there is not a conductive
dense screen
> underneath (even for the "center fed models" not using the ground as
a
> current sink) the flux penetration of the ground will induce loss
currents
> in the area immediately underneath. This loss is completely
independent of
> any "ground connection" on the vertical.
> >
> > Loss factor #4:
> >
> > High current losses due to compromise tuning for multibanding,
shortening
> for convenience in construction can occur at aluminum joints, traps,
and in
> miscellaneous connections in the antenna.
> >
> > Loss factor #5:
> >
> > Trees, buildings, etc in the vicinity will all attenuated a
vertical
> signal to a higher degree than horizontal signals. This is
especially true
> at the low angles we are targeting in the first place.
> >
> > It's important to remember in this thread that the original post
had to do
> with a very limited installation of a compromise multiband vertical
antenna,
> not a W8JI ultimate vertical paradise.
> >
> > IF the owner has the time and inclination to do some work with
radials and
> specifically go after the loss factors, then some considerable
success can
> be had.
> >
> > UNFORTUNATELY, only a tiny percentage of the residential vertical
> installations I have seen had 1 through 5 above attended to. Most
were
> significantly afflicted with these factors, initially not knowing
what was
> happening to them, and even a LOW horizontal antenna improved their
results
> dramatically.
> >
> > If one is going to do the "vertical" thing, DO the ***ENTIRE***
vertical
> thing, or don't bother. Don't just stand the thing up, run coax to
it, and
> think you are done. This is particularly true for the QRP crowd,
where the
> 6-10 db disadvantage you can accumulate in factors 1-5 isn't there
to give
> away in the first place.
> >
> > 73, Guy
> > K2AV
> >
> > >
> > > From: "Bob Lewis (AA4PB)" <[email protected]>
> > > Date: 2003/06/06 Fri PM 04:40:35 EDT
> > > To: "Elecraft" <[email protected]>
> > > Subject: Re: [Elecraft] Windom Antennas
> > >
> > > > ...the joke about verticals is "radiate equally poorly in all
> > > directions".
> > >
> > > I think verticals get this "bad rap" because the typical ham
doesn't
> > > install them correctly. No good radial or counterpoise system -
shove
> > > an 8-foot rod in the ground and call it "grounded".  I wonder
how well
> > > a dipole would perform if you only put up half of it.
> > >
> > > The bottom line - it's usually easier to put up a "good"
horizontal
> > > antenna than it is to install a "good" vertical.
> > >
> > > _______________________________________________
> > > Elecraft mailing list: [email protected]
> > > You must be a list member to post to the list.
> > > Postings must be plain text (no HTML or attachments).
> > > See: http://mailman.qth.net/mailman/listinfo/elecraft
> > > Elecraft Web Page: http://www.elecraft.com
> > >
> >
> > _______________________________________________
> > Elecraft mailing list: [email protected]
> > You must be a list member to post to the list.
> > Postings must be plain text (no HTML or attachments).
> > See: http://mailman.qth.net/mailman/listinfo/elecraft
> > Elecraft Web Page: http://www.elecraft.com
>
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be a list member to post to the list.
> Postings must be plain text (no HTML or attachments).
> See: http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com
>