[Elecraft] Windom Antennas

Fri Jun 6 21:18:00 2003

 I had the great fortune to have dinner with Jerry Sevick years ago (late=
=20
80s).  He was guest speaker at a radio club I used to belong to, the Rari=
tan
Bay Radio Amateurs, based out of Sayreville, NJ.  I was VP and it was my =
job
to entertain the guest speakers (i.e. make sure they got fed!)  Anyway, i=
t
was a delightful dinner and Jerry proved to be one of the best guest
speakers we ever had (at least while I was there).=0D
 =0D
73 de Larry W2LJ=0D
QRPARCI #4488  NJQRP #47=0D
FISTS #1469  QRP-L #778  FP# 612=0D
 =0D
email: [email protected]=0D
URL: http://www.qsl.net/w2lj=0D
 =0D
-------Original Message-------=0D
 =0D
From: George, W5YR=0D
Date: Friday, June 06, 2003 18:38:06=0D
To: Guy Olinger, K2AV; Bob Lewis AA4PB; Elecraft=0D
Subject: Re: [Elecraft] Windom Antennas=0D
 =0D
Guy, you must have had some adverse experiences with verticals somewhere=0D
along the line . . .=0D
=0D
I use the Butternut HF-9V, ground mounted over a field of 18 radials each=
 25=0D
ft long. The antenna resonates per the CIA-HF impedance instrument in eac=
h=0D
of the 9 bands. It loads well with very low line SWR. Based upon the SWR,=
=0D
impedance measurements and the design of the radial field, the total grou=
nd=0D
loss is likely no greater than 3 dB and is possibly less. This is in a=0D
typical backyard with trees, power pole and lines nearby, etc.=0D
=0D
The key thing about the vertical is that in competition with a pair of=0D
20-meter extended double zepps, mounted at 38 ft and at 90 deg, and a low=
=0D
80-meter horizontal full-wave loop, the vertical many times produces bett=
er=0D
signals than any of the other wire antennas.=0D
=0D
I participate in the QRP-L Fox Hunts and most QRP operating events and fu=
lly=0D
a third of the time, the most difficult contacts are made with the=0D
vertical.=0D
=0D
I find that it is noisier than the wires but not exceptionally so. Late a=
t=0D
night when 20 meters is largely asleep, it is interesting to monitor 14,1=
00=0D
and listen to the beacon stations and try the various antennas. You would=
 be=0D
surprised at how often the vertical returns the best signal, even from=0D
locations favored by the patterns of the EDZs.=0D
=0D
All your points are technically valid, and taken in summation would persu=
ade=0D
anyone that using a vertical is heresy. Nonetheless, with proper=0D
installation and attention to the points you mentioned, a vertical - even=
 a=0D
"compromise" multi-band vertical - can provide superior performance when=0D
conditions favor.=0D
=0D
You might enjoy reading of the research done in the 70's with shortened=0D
verticals by Jerry Sevick, W2FMI. His work was published in QST at the ti=
me=0D
and is reprinted in appendices in "Building and Using Baluns and Ununs."=0D
=0D
Jerry provides quite detailed loss measurements and the like for various=0D
radial configurations, etc. I might add that Dr. Sevick, formerly a=0D
scientist at Bell Labs, knows what he is doing, and his work can be relie=
d=0D
upon for accuracy.=0D
=0D
Neither his work nor my experience and measurements can support your dire=
=0D
predictions of 6-10 dB loss with a vertical for the reasons you enumerate=
=2E=0D
=0D
73/72, George=0D
Amateur Radio W5YR - the Yellow Rose of Texas=0D
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE=0D
"In the 57th year and it just keeps getting better!"=0D
<mailto:[email protected]>=0D
=0D
=0D
=0D
=0D
=0D
----- Original Message -----=0D
From: "Guy Olinger, K2AV" <[email protected]>=0D
To: "Bob Lewis AA4PB" <[email protected]>; "Elecraft"=0D
<[email protected]>=0D
Sent: Friday, June 06, 2003 5:00 PM=0D
Subject: Re: [Elecraft] Windom Antennas=0D
=0D
=0D
> I agree with your statement about poor installation. Unfortunately it's=
=0D
quite WORSE than that. Lack of a proper ground connection is only loss=0D
factor #1. Note that poor series ground conductivity at a ground located=0D
feedpoint does not apply to a series of "vertical" antennas that have fee=
d=0D
points up the antenna. But the rest below DO.=0D
>=0D
> Loss factor #2:=0D
>=0D
> An antenna will initially radiate about half its power below the horizo=
n.=0D
Horizontally polarized energy will essentially bounce at some angle, at f=
ull=0D
strength.=0D
>=0D
> Vertically polarized energy will usually be absorbed instead of bouncin=
g.=0D
UNLESS the ground media at the bounce is salt water or laced with=0D
conductors, like extensive dense buried radials. Both of those are rare i=
n=0D
the typical installation, since the vertical was chosen because of LACK o=
f=0D
good supports for horizontal antennas, or limited space, which means limi=
ted=0D
space to place radials, if even practically possible.=0D
>=0D
> Loss factor #3:=0D
>=0D
> A vertical antenna has a lot of flux directly underneath. It penetrates=
=0D
the ground to a surprising degree. If there is not a conductive dense scr=
een=0D
underneath (even for the "center fed models" not using the ground as a=0D
current sink) the flux penetration of the ground will induce loss current=
s=0D
in the area immediately underneath. This loss is completely independent o=
f=0D
any "ground connection" on the vertical.=0D
>=0D
> Loss factor #4:=0D
>=0D
> High current losses due to compromise tuning for multibanding, shorteni=
ng=0D
for convenience in construction can occur at aluminum joints, traps, and =
in=0D
miscellaneous connections in the antenna.=0D
>=0D
> Loss factor #5:=0D
>=0D
> Trees, buildings, etc in the vicinity will all attenuated a vertical=0D
signal to a higher degree than horizontal signals. This is especially tru=
e=0D
at the low angles we are targeting in the first place.=0D
>=0D
> It's important to remember in this thread that the original post had to=
 do=0D
with a very limited installation of a compromise multiband vertical anten=
na,=0D
not a W8JI ultimate vertical paradise.=0D
>=0D
> IF the owner has the time and inclination to do some work with radials =
and=0D
specifically go after the loss factors, then some considerable success ca=
n=0D
be had.=0D
>=0D
> UNFORTUNATELY, only a tiny percentage of the residential vertical=0D
installations I have seen had 1 through 5 above attended to. Most were=0D
significantly afflicted with these factors, initially not knowing what wa=
s=0D
happening to them, and even a LOW horizontal antenna improved their resul=
ts=0D
dramatically.=0D
>=0D
> If one is going to do the "vertical" thing, DO the ***ENTIRE*** vertica=
l=0D
thing, or don't bother. Don't just stand the thing up, run coax to it, an=
d=0D
think you are done. This is particularly true for the QRP crowd, where th=
e=0D
6-10 db disadvantage you can accumulate in factors 1-5 isn't there to giv=
e=0D
away in the first place.=0D
>=0D
> 73, Guy=0D
> K2AV=0D
>=0D
> >=0D
> > From: "Bob Lewis (AA4PB)" <[email protected]>=0D
> > Date: 2003/06/06 Fri PM 04:40:35 EDT=0D
> > To: "Elecraft" <[email protected]>=0D
> > Subject: Re: [Elecraft] Windom Antennas=0D
> >=0D
> > > ...the joke about verticals is "radiate equally poorly in all=0D
> > directions".=0D
> >=0D
> > I think verticals get this "bad rap" because the typical ham doesn't=0D
> > install them correctly. No good radial or counterpoise system - shove=
=0D
> > an 8-foot rod in the ground and call it "grounded". I wonder how well=
=0D
> > a dipole would perform if you only put up half of it.=0D
> >=0D
> > The bottom line - it's usually easier to put up a "good" horizontal=0D
> > antenna than it is to install a "good" vertical.=0D
> >=0D
> > _______________________________________________=0D
> > Elecraft mailing list: [email protected]=0D
> > You must be a list member to post to the list.=0D
> > Postings must be plain text (no HTML or attachments).=0D
> > See: http://mailman.qth.net/mailman/listinfo/elecraft=0D
> > Elecraft Web Page: http://www.elecraft.com=0D
> >=0D
>=0D
> _______________________________________________=0D
> Elecraft mailing list: [email protected]=0D
> You must be a list member to post to the list.=0D
> Postings must be plain text (no HTML or attachments).=0D
> See: http://mailman.qth.net/mailman/listinfo/elecraft=0D
> Elecraft Web Page: http://www.elecraft.com=0D
=0D
_______________________________________________=0D
Elecraft mailing list: [email protected]=0D
You must be a list member to post to the list. =0D
Postings must be plain text (no HTML or attachments). =0D
See: http://mailman.qth.net/mailman/listinfo/elecraft=0D
Elecraft Web Page: http://www.elecraft.com=0D
=2E=20

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