For a low horizontal loop you can wind it through trees (I use #12 black
plastic wire that comes in 500 feet rolls from Home Depot and less than
$20). If not there is no reason why it can't be hung from towers but I
feel that it needs to be several feet away and not connected directly.
There has been a big discussion about low full wave loops (say 35 to 50
feet). Dr. Dave W7FB (Ex W0MHS) has a PHD in Antenna ralated theory and
claims a horizontal loop has what he calls elliptical radiation that is not
measured by the modelling programs such as ELnec. This is why most find
that it works better on the low bands than expected. Dave was in Atlanta
long enough to help put up or design many horizontal loops. There was an
article by a German ham in 73 in the late 1970's. He was living in Atlanta
and going to Georgia Tech.
The article is called the German Quad. He had good luck on 80 and 40 with a
full wave 80 loop. I have a loop that started out as an 80 meter loop at
my Island home on St. Simons Island, Georgia. The loop is actual 40 feet
longer than an 80 meter loop as I had to add to it to make the ends meet. I
run it through a tuner. True it has great skywave on 80 and 40 but I have
worked Europe on both bands running 100 watts during the ARRL DX SSB. I
also have 6K QSOs on 20, 15, and 10 IOTA frequencies and have run big pile
ups at times as NA-058. It does well on 17 and 12 also.
I had up a 390 foot loop at my home QTH which I capacity loaded per the
article in QST and later the ARRL Antenna Anthology. I forget the W7's call
but in the April QST its mentioned in the 25 years ago in QST. He reasoned
that since the quad was a magnetic antenna it was best to add capacity
loading to electrically lengthen the antenna. Working from my roof I was
able to tune the loop down to WSB (750) with what he called center in and
back out capacity wires. Just with the center in wires (from the middle
points between the feed point and the opposite side) I tuned the loop for
1845Khz. I found it mostly skywave on 160 ( I remember the ham in Kentucky
that told me I was the loudest station in the CQ 160 SSB...just like a local
and even louder than WB9Z). On DX (NA/SA/EU) I was beaten out easily by
locals running L's and even inverted V's. But on 80 I coould easily run
Europeans on SSB.
Several have had good luck using a full wave loop at less than 10 feet of a
RX antenna. AB0X had an excellent article in the August 1989 CQ on using a
version made from small coax as a shielded link loop. My version was laid
on my roof and then run out in to near by trees.
It worked very well although it was only 200 feet and part of the coax came
down to the receiving antenna jack on the Yaesu.
Dave K4JRB
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