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LOVE MY LOOP"
"I Sure Did"
An All Band 80 Meter Loop
by John Reisenauer, Jr.,KL7JR
Presented here with his
from an article published in 73
"When I think back a few years
ago I had 10 acres
to use for my antenna farm. It was
great to be able to put wires
on the towers or off my
garage or in the field anywhere I
it's a two car garage to experiment in and then
head off somewhere in
the motor home to test the
antennas. I'm in a deed-restricted community of Town
that does not allow any antennas except for
Dish Satelllite (and the 40m loop on my roof
that has been
hidden from everyone for 2 years), hi hi!."
"I LOVED MY LOOP~~~~~I SURE DID"
Now let me tell you about
Much has been printed
in QST over the years on loop antennas. Experimenting with wire antennas
is a favorite pastime for me. I recently had great results with a delta
loop on 10 meters and a rectangular loop on 20 meters, (50+ countries in 3
weeks of casual operating!), then I decided to take the plunge and put up
a 80 meter full-wave horizontal loop which would allow operation on all HF
After gleaning all the info in the articles referenced below,
and adding my own twist, the antenna would either work or be a
happy to say this simple antenna far exceeded my expectations!
found to be so appealing about this antenna was that it was fairly
economical and easy to build and install, works on all HF bands and
requires no special feed networks, only a transmatch, coax and some
METER HORIZONTAL SQUARE LOOP
Length of a full-wave
80-meter loop is about 270 feet long (1005 divided by frequency in MHz) or
about 67 feet per side. I use "about" because exact numbers are not that
critical according to my results.
In my opinion, when constructing
antennas, not only is the old saying "the higher the better" true, but
also "the longer the wire the better" may also fit some loops.
lived on 10 acres in the country, I decided to make my horizontal loop
longer to start with to better fit my backyard. So, my "longer" loop is
about 1.25 wavelengths on 80 meters (2.5 on 40m, 5 on 20m and 10 on 10m)
and is installed between 30 to 40 feet in the air.
versions, say 75% of a wavelength may also work fine if you don't have the
room for a full-wave or longer antenna.
According to antenna experts, a
circular loop is "ideal", but impractical for most hams. I found a square
or even a rectangular loop is easier on the pocketbook and muscles to put
up and would provide about the same results.
To support my loop made
from salvaged telegraph line wire from the Yukon Territory (just think
about the stories this wire has already told!),
I used my 50-foot tall
tower and three masts, each 35 to 40 feet long, made from 2 inch
galvanized water pipe. Each support is "supported" by one ¼ inch diameter
steel guy wire attached by a u-bolt in the opposite direction of the wires
"pull" and a small pulley with 3/8-inch diameter rope for hoisting up the
wire to the top of masts (Figure A below).
Figure A: Detail of a Mast
The telegraph wire is #6 AWG
copper-clad steel and not all that easy to work with, but the price was
For the feedpoint connection I used a 1-1/2" PVC pipe T
terminating the antenna wires to a 1/4 " eye bolt as used on some
commercially made baluns.
RG 213 coax (chosen for
strength, durability and because I may use an amp) terminates on the
eyebolt nuts with two flat washers.
The coax is taped to a ten-inch
long bottom extension of the PVC T to remove strain on the hanging
Silicon caulk was then applied to the connections for
For antenna insulators, I used porcelain electric
Once the support masts are complete with guy
wires and pulleys and installed, raising the wire becomes a one-man
On my tower I installed a six-foot long 4x4 painted wood
post hanging off near the top of tower for one of the four required
supports (Figure B below).
On the post end that is further away
from the tower I used an electric service entrance insulator fastened by
u-bolt to "float" (ref. ARRL Antenna Book page 5-17) the antenna wire as
with the other three supports. I wasn't sure if all "floaters" would
actually allow the wire to float, but they did quite easily.
antenna and feedline connections were made up on the ground then hoisted
up each mast one-by-one with the rope and pulley. Once the wire was in the
air and about a foot or two away from the masts, I merely tied off the
rope to whatever was handy (i.e.- nearby barn roof, tree etc.). I only had
to take up a bit more slack from one pulley (the wire pulls through all
the pulleys) for final wire sag adjustments. Since my wire was very heavy
duty, I could pull it tight. Your sag will depend on the type and size of
wire used. Smaller gauge wires will break if pulled too tight or used on
long spans - just ask me!
My loop is fed about mid-span and the coax
drops 30 feet straight down into my shack.
Figure B: Detail of the Tower
HOW DOES IT
During the first 3 months of
use, (October through December), 75 percent of my QSOs on 10 and 20
meters were either 5x7 or 5x9 reports "both ways". About 75
percent of them being with stations outside North America *(about 10%
were 5x9 +20!), and about 20 percent of the total QSO's were 5x5 to
5x1 quality "both ways".
For those doing the math, call the remaining 5
percent split equally either 3x3 signals or simply "no contact at
all" (you can't work them all!).
Also, my log indicates "sent" report
was the same as "received" most of the time. I even broke several big
pileups on the first or second call.
Directivity? Well, the
loop seemed to work just fine equally in all directions (I'm still
scratching my head!). That's what I really like about this
Gain, you ask? Well, some..... depending on your choice of
feedline and how high you install your antenna. L.B. Cebik W4RNL goes into
a lot of detail on gain (see ref #4 below) in his article so I won't get
into that here.
Although I have mostly tried this antenna on
10 and 20 meters, I was also pleased with a weekend of experimenting on 15
and 17 meters.
DX worked on 15 meters: KL7, HL5, JR1, KH0, RV9 and
DX worked on 17 meters was KL7 and OH1. Many Ws and VEs were also
worked on 15 and 17 meters.
Both bands produced about the same results
on signals mentioned above over the two-day period of tests.
confident this antenna will produce good results on 40 and 80 meters as
well. I know it tunes 40 and 80 meters quite fast!
To give a better perspective on
this versatile antenna, on December 29, 2001, I worked my buddy Rick KL7AK
back-to-back on 15, 17, 12 and 40 meters! On 15 and 17 meters we both
exchanged 59 +20 reports, on 12 and 40 meters we were up to 55 quality.
Not bad for a piece of wire, eh?
I did learn however, both 300
watt manual tuners (MFJ and Vectronics) that I used took some time to tune
the loop, with a couple bands requiring a lot of patience! I did not try
the auto-tuner on my TS-570D since my Tucker 1.5 kW tuner easily handled
the job quite fast on all bands 80-10 meters.
My tribander will
remain stored in my garage as I work on a new loop design around 1200 feet
long supported off of 60 foot tall power poles (but that's another
article!) - when I tire of this antenna that is!
I highly recommend
this antenna. Good luck with your antenna experimenting! Any and all
feedback is appreciated.
**I worked all over the USA
and Canada, including: KL7, KH6, JY4, V47, KH0, WP2, WP3, HP1, FO, PA2,
8R1, DS3, G3, LU1, ON7, JA (all), DU1, I2, ES1, UA9 and UA6 to name a
Some final? words!
Believe me when I say, it was the best all
around antenna I ever used.
I liked it so much I decided not to waste
my time and effort putting the tribander back up. Often times on 80m
nets I was 20 over S9 to other
WA and OR stations who were 100-200
miles away. I wasn't using an amp
either. I regret only
using the antenna 4 years. I even had plans for a higher and longer
version in the future as mentioned in the article.
I guess we all have had a favorite antenna at one time or another.
summary........" I LOVED MY LOOP"
1. "The Loop Skywire",
by W0MHS, QST Nov. 1985, page 20 and ARRL Antenna Book 16th edition, pages
2. "The Droopy Loop" by KJ7MZ, QST July 1996, page
3. "Loop Antennas", ARRL Antenna Book, 16th edition, pages
4. "HO-HO-HOHPLs" by W4RNL
(www.cebik.com) Do a
(Note: #1 is available to
download from ARRL website, do "search" for "constructing loop
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