In the the Fall of  2005 I was frustrated by not being very competitive on 160.  I went off to Lowe's and bought a thousand feet of wire.  I put up an inverted L and then used 500 feet of wire to put down 16 radials, each 30 feet long at the base of the tower. They were laid out all nice & neat. They really looked good. I was ready to knock 'em dead. The 2005-2006 160 season was ok, but I came far from setting the world on fire.  Something just wasn't quite right. This past summer I asked a lot of questions on the Topband reflector and began accumulating wire.  In late September I started putting down radials.  I Put down close to 3000 feet of wire in enough radials to bring my total to 63 or 64. They are all lengths; some are bent, some are only 30 feet long, some go out around the side of the house and are 120 or so feet long. Some are 50 feet long and some are 80 feet long.  My wife said it looked like a giant spider had been busy out around the base of the tower. I also put up a K9AY type receiving array.  Bottom line;  This season already I have worked 15 or 20 new countries including Alaska,  5A7A, HC8N, a couple of Russians, a SM,  a couple of JA's, etc, etc. All with 125 watts. I talked online with lots of folks about how many radials I needed, and consistently the answer came back; If you don't have room for 1/4 WL radials, the magic number is 60-65. Don't worry if some are long & some are short. Just do it. The gist of this story is that you need to plan to put down a significant amount of wire.  Lay the radials on the grass, pull them tight, and tie them down along each one with "U" shaped wires (about 3" long) pushed in the ground. In the spring fertilize a bit and the radials will disappear under the grass after it has grown for a month or so and has been cut a couple of times.

The K9AY Type Array

Below are pictures & discussion of my K9AY type receiving array.  I use the term "K9AY type" because  my configuration deviates from the classic K9AY construction. Look Here . 

As I was researching terminated loop antennas I ran across several references to the KAZ antenna.  This is a Delta Loop configuration used by the SWL folks in which the feed point is at one end of the base leg, and the termination is at the other end.  I modeled this antenna in EZ-Nec and moved the feed & termination to the middle of the base leg as per K9AY.  EZ-Nec showed that moving the feed & termination anywhere either side of the center of the base leg gave essentially the same results as long as the configuration remains balanced (feed on one side of center and termination on the other). EZ-Nec also showed that higher F/B ratios can be achieved with a delta configuration than with the classic K9AY configuration. As luck would have it, I had a good strong tree limb exactly in the right place and at the right height to act as the apex support for my array.  The delta configuration was also much easier to assemble than the classic K9AY configuration because the base leg gives excellent performance at only 6 inches above the ground. The apex is at 18 feet, and the base legs are +/- 20 feet (40 feet over all) from the center. This is a little larger than the classic K9AY array.  After spending quite a bit of time modeling this antenna, it appears that gain is a function of the area of the triangle, therefore the base leg could probably be 30 feet rather than 40, and the only performance loss would be in gain. If the base legs are shortened I suggest that the apex be lowered to maintain the same aspect ratio. I used a terminating resistor of 500 ohms.  This seems to perform well on 80 & 160. I really didn't put a lot of effort into accurately determining the exact value for the termination as it doesn't seem that critical.  The relay box at the antenna is right straight out of the K9AY article as is the switch box in the shack.  I had a significant amount of RG-11 size 75 ohm CATV coax and used that for the feed line.

There has been a lot of discussion about surrounding objects affecting the performance of the array. I actually don't know if that is true or not.  However, the southwest end of the NE/SW loop is 8-10 feet from a chain link fence on the side, and the back leg of that fence is right off the end of that loop about15 feet.  The southeast end of the SE/NW loop is about 1.5 feet from the chain link fence and the northwest end of that loop is roughly 20 feet from a small metal storage shed. The leg northeast of center runs within 1 foot of the guy wires for the tower and looks through the house at a distance of about 30 feet.  The center of the array is approximately 50 feet from the tower that supports the Inverted L. In spite of all of this, the antenna performance is more than satisfactory. I have made no effort to measure the F/B ratio. I can see that there is some, but for me that isn't nearly as important as noise reduction, and the antenna does that in grand style. Noise that is prohibitive on my Inverted L doesn't exist on the RX antenna. I can hear the DX and in my book that makes it a real winner.

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