I have always been very impressed with sky loop antenna performance. Most people ignore this
fine antenna, and stick up a dipole... Sad!
The ARRL wire antenna books states that the Loop is "magical" and I agree.
I decided to make a serious effort to improve on a great thing.
I have created what I call the AG6IF Talented Balun and loop.
The loop antenna will be much quieter noisewise than a vertical.
They operate without a tuner on multi bands, very nicely on their design frequency, and multiples, ie, 80 40 meters, and also 20, 15 and to a degree even 10 meters.
I have been using a 40 meter loop, because that is the size that I can erect in my size lot.
My loop is 128 feet long, and is a triangle shape. (Called a Delta Loop)
It is roughly horizontal, and supported by 3 corners. Each corner is about 6 feet in the air.
SWR is about 1 to 1 on 40, 20, 15 and the high part of 10meters.
The Talented Balun is what makes the magic even better, here is why:
Most Loops seem to be fed with a 4 to 1 balun and a piece of 50 ohm coax. This assumes the loop is 200 ohms, (which it isn't).
It works ok but it isn't perfect.
A regular loop has an impedance more towards 137 ohms than 200 ohms. A 4 to 1 balun is designed for a 200 ohm antenna roughly.
The 2.5 to 1 balun that I use is better at getting the antenna impedance closer to 50 ohms, and when this happens, less power is lost, in BOTH directions.
In other words, you can hear stations better, and you can transmit farther.
I have created a 2.5 to 1 balun to connect coax from Rig to Loop and this has been performing very well.
I have made contacts in Brazil using 1 watt of power with a Talented Balun Loop only 6 feet in the air.
I have also made a contact into Kenya, nearly 9700 miles from my home in California with no power amplifier of any kind.
A couple friends, both antenna guru's, saw what I had and urged me to produce and sell this rig...at first I was reluctant..but changed my mind.
I have not seen any Loop antennas available for sale, so I decided to sell my homebrew setup in my Ebay store.
the 40m version Includes 128 feet of stranded insulated copper wire (speaker wire type), and a 2.5 to 1 balun ready to hoist up and operate.
The Balun will work equally well with a larger wire loop or smaller if your QTH changes..
So if you buy a 40, and have room for 80m or 160 meter loop, just connect up longer wire. The recommended wire lengths are printed inside the Balun enclosure.
The normal loop calculator uses 1005 / Freq. to determine the length of the wire.
This is an old standard that has existed forever, and frankly, it works ok but under the microscope, I have found it to be a series of compromises.
The "magic" however is improved when analysis is completed and I took a good look at this 1005 standard and found some holes in the theory.
With the Talented Balun, the 1005 number is actually 990 at the higher end and 850 at the 160 meter band, the slope is generally linear.
In other words, the Talented Balun makes the antenna wire seem longer, so the 1005 constant can be reduced.
2m band about 7.5 feet, mounted vertically for vert. polarized repeaters
10m 35 feet
20m 63 feet
40m 128 feet
80m 250 feet
160m 508 feet
Generally, a 40m loop will work (1.2-1 swr) on 40 20 15 and 10 meters, and even 2* (* except for the polarization issue)
Interestingly, an 80m loop will work on 2 of the 3 WARC bands, 80 40 20 17 15 12 and 10 and 2m* Still needs a tuner on 30 meters though.
As you might imagine, a 160m loop works on 160 80 40 20 17 15 12 10 and 2*
hope you found this helpful, please check eham for a Talented Balun review, and also check my qrz page for more details.
Here is a comment from a recent customer:
"Having a ball on hf after being off for so many years.
In the last few months up at the lake I have had up a windom.G5RV . Gap titan dx and a Bobtail curtain.they are all coming
down. There is no reason to have anything up but your loop, with 6 s units better than anything else and no tuner required.
Almost too good to be true.you should mention in your e bay ad to see your review on e ham !
What a gas to hear some one from moscow, germany,iceland,scotland, say , BOY , you are very strong here, 10 db over S 9 !!
Jim.just had to tell you this.turned on the hf radio after dinner to have a listen.new Alinco 100 watt Dx SR8.
Could not believe the pile ups on a a Cyprus station
And a Guam station.Thousands of folks calling these two guys.
I was answered on the FIRST call and got a 10 db over S9
From both guys.Both on 18 mhz.
You got to be kidding me !!!!!
Thanks for reading my review, hope to work you on HF!