cant work 80 meters, I dont have a good 80 meter antenna"
How many hams have made a statement like the
title of this piece? Quite a few, Id be willing to bet. There are
numerous reasons why people shy away from trying to put up a good antenna for this band:
I dont have enough room for a full-length antenna.
I cant get an 80-meter antenna high enough to do any good.
You cant work DX without some kind of directional antenna and
thats not very possible on 80.
Takes too much wire.
I could put something up but the coax would be too long and lossy.
I could put something up but the coax would be too expensive.
Im sure there are several other reasons you could give but
Im here to tell you, Im running an 80-meter antenna that, by all definition
and rules of antenna theory, it shouldnt work. At least, it shouldnt
work as well as it does. Let me describe this strange quirk of physics and then
Ill enumerate some of my success with it.
My antenna is 130 feet long, made of #12 stranded wire.
Its fed in the center with 450-ohm ladder line and I use a Ladder Grabber center
insulator, which is an excellent product from EmTech of Tracyton, Washington.
It cost me only $8.00 postpaid when ordered through the Internet and a recent check
shows it still the same price.
[The "blob" on the left side
of the insulator is not some secret trap material made to make it work better. It's
a piece of leaf which got wrapped around the wire and it was just too far away for me to
Antenna purists will tell you that unshielded feedline, such as
ladder-line, should always be supported away from touching metal, wood, trees, or anything
which could upset the balance feature of the line. I believe that theory and
Id certainly do that if I could. Where the feedline exits the house I do use
an insulated PVC flexible hose to (sort of) keep it away from the other coax feedlines.
[Some day I'm going to gather
up all these feedlines to make them look nicer............maybe next week........ or next
From the point where the feedline exits the attic over to the center
insulator of the antenna, Id like to keep it totally clear of everything, however, I
just couldnt do that. Ive got a big tree in the way so I just wove the
ladder-line through the branches. As I mentioned, an antenna purist would NEVER
weave this feedline through a tree
. but Im not an antenna purist.
Ive mentioned before, in other articles, that my antenna theory is, do the
best you can. Put up the best antenna you can, as high as youre able and then just
use it. Youve done the best you can so just use it and enjoy it.
[It's difficult to see the 450-ohm
ladder-line as it threads through the tree but if you squint just right, you'll see it.
I made no effort to isolate the feedline from the branches.]
Another thing, which will make antenna purists wince, is the
coupling I added to my ladder-line antenna. I planned to experiment with various
antennas fed with 450-ohm ladder-line so out among the tree branches I terminated my
ladder-line with a pair of banana jacks mounted in an old pill bottle. Then, when I built
another antenna I could plug it into this coupling and try it out. So far
Ive not tried any other antennas since my first one worked so well. The ladder-line
feedline coming from my 80-meter antenna is terminated in a pair of banana plugs that
plugs into the coupling at eye level. So far it has weathered and worked quite well.
[This is the pill bottle connection
to allow hooking various experimental antennas to the ladder-line coming from the
hamshack. It's not completely waterproofed so I periodically have to dump the water
Well, at least I know I should have my antenna up pretty high.
A full wavelength would be optimum but it should be at least a half wavelength.
On 3.750 MHz, a full wavelength would be just short of 250 feet, which, for me, is
far more than impossible, and not even within the "dreaming range." Even a
half wavelength is almost 125 feet and thats not even a possibility for me. I
do have several towers but the shorter one is only 39 feet and thats what I had
available for an end support for my 80 meter antenna. Actually, the support bar
where its hooked is at 38 feet or so above the ground. Currently, I have a deep lot
with an acre and a quarter but I have nothing at the back part of my lot for an anchor so
the other end of my antenna is tied to the fence and is no more than 4 1/2 feet off the
ground. Certainly this antenna would qualify for a good NVIS antenna but this is
not NVIS territory.
[This tower is a 40 foot Rohn 25. The bracket where
the antenna's pulley is attached is a foot or so below the rotator. The picture on
the right shows this bracket up a bit closer. This is the HIGH end of the antenna.]
[The left picture shows the end of the
antenna running out to attach to the fence. The grey end insulator is just about in
the center of the picture. The right picture shows that same end insulator from the
other side and gives a good idea how low this antenna really is. You might be able
to see the ladder-line feed coming out from the tree.]
WHAT? A successful 80 meter antenna thats only 38 feet
high on one end and 4 1/2 feet on the other? Yep, thats what Im saying.
How good is it? The following are some of the stations I have contacted on 80
meters with my strange antenna:
ZL1IU New Zealand - April 2007 SSB
3B7C St. Brandon Island September 2007 SSB
OK5R Czech Republic March 2007 - SSB
HC8N Galapagos Islands October 2007 - SSB
AO8A Canary Islands October 2007 SSB
ZY7C Brazil October 2007 SSB
ON4UN Belgium March 2007 SSB
HG3DX Hungary March 2007 SSB
CN2R Morocco October 2007 SSB
C52C The Gambia October 2007 SSB
KH7XS - Hawaii November 2007 SSB (now twice)
OE6MBG - Austria - November 2007
EI6S - Ireland - November 2007
Many stations in the Caribbean area
Every time I get ready to try to work a DX station on 80 meters I
tell myself, "Theres no way I can get to them with that low-down antenna.
I have not, however, told my antenna that information so it continues to surprise me and
continues to produce good and surprising contacts. Perhaps all the praise should go to the
abilities and equipment of these stations on the other end. I have no doubt that
plays a part but the fact remains that my signal, hugging the earth, seemed to somehow get
to where they are.
I should also describe the other end of this antenna. When the
ladder-line enters the attic it runs for a while and attaches to a large 4:1 balun.
This balun is fed with 50-ohm coax, which runs the rest of the distance into the hamshack,
a distance of less than 15 feet. The coax runs to my Dentron MT-3000A antenna tuner,
which takes care of any misadjustments. I do run a kilowatt and I must admit that
power here often helps a great deal. Its often been said that its better
to have an extra good antenna rather than high power because the antenna helps on both the
transmitting and the receiving end. In my case, however, I didnt have the
opportunity to put up any better antenna so this one seems to work well enough on both
Most of this article has dealt with the use of this antenna on 80
meters but it goes without saying that if you are actually running your antenna through a good antenna tuner, you can cover all ham bands from 160
- 10 meters and all the frequencies in between. This antenna would be a good choice
for an antenna when the ham could only put up one antenna. My friend Jerrie - KD5KD
has been using an antenna like this with great success on his Navy MARS net which is near
the 80 meter band. Jerrie has his antenna mounted as an inverted V with the center
at about 38 feet and the ends drooping down to around 20 feet off the ground.
Note that I said "through a good antenna tuner"
and that doesn't particularly mean an expensive antenna tuner. I would recommend an
external tuner be used, either a manual or automatic model. Many folks consider
their antenna tuner to be the auto tuner build into their transceiver but most of those
tuners have a limited range. Typically, the tuners built into commercial
transceivers cannot tune anything above about a 3:1 SWR (about 20 to 150 ohms) and that
may be insufficient to tune this antenna on some frequencies. A good external
tuner may be able to match impedances from 5-10 ohms to over 1000 ohms. This is
particularly important if you plan to use this antenna over a wide range of bands and
By the way, this antenna runs roughly from Northeast to Southwest.
At this low altitude, however, I doubt that the pattern is anywhere close to a
typical dipole's pattern. I suspect that if I tried to run the figures for this
antenna through an antenna modeling program it would come to a screeching halt and display
the message, "You've GOT to be kidding!!!"
My final advice is If you want to put up an 80-meter antenna
but you hesitate because you think you can't have any success, I'd say, "just do
it." Do the best you can with what you have available. Put up what you
can and as high is you can. Even though its not an antenna which is destined
to be displayed on the cover of CQ Magazine, just go ahead and use it and enjoy it.
It might just surprise you.
Created November 7, 2007
Page visited 15 times
Last updated 11/06/2012 16:59:21 PM
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