I still don't have all of the results from my testing, and I still have some testing to accomplish, but I sure have been surprised by the results I've experienced over the last couple of weeks after building several of these: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjG_Jjw5_zJAhXIMj4KHcg_BJYQFggcMAA&url=http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf&usg=AFQjCNGuS5GPn3IYYBaz4GEUNQVxf0xxfw&sig2=TrZ2raPmPZLWF_gQuEiCNQ I'm taking a break from testing them against an approximate 137 foot doublet at about 35 feet above earth, and a 21 foot base loaded vertical over a ground plane of sections of chain link fence laying on the ground. I still don't believe what I'm seeing for impedance at the end of the line, and what I'm hearing on the non-WARC 80-10 meter bands. I feel like I have hit some simple "magic" antenna that will go "poof" when I wake up. There seems to be a lot of others who have also found similar results. I don't want to promote competitors to QRZ, and I especially don't want to promote those who have taken advantage of the initial design and the many kits made available by the Emergency Amateur Radio Club of Hawaii. But, if you "Google" the term "EZ WIRE END FED ANTENNA" or "EARCHI Review" you should find what I'm talking about. I spent several hours last night changing the radiating element lengths and 4-wire and 8-wire ground plane/radial lengths, including removing the ground planes completely from the area. For the latest testing, only the transformer and coax have remained unchanged. Overnight we got a couple of inches of rain, so I though things might change. They didn't. The complex impedance measurements were the same at noon today as they were at about 7:00 PM last night. If you have downloaded the PDF link above, my transformer is exactly as shown, on a T106-2 core. It is a very simple tri-filar winding on a T106-2 core, resulting in a 9:1 voltage un-un. I've settled on exactly 50 feet of 50 Ohm RG-58/U as the feedline, as it is easy to make, buy, and use. I tried a number of other coax lengths, and I've tried various lengths of 75 Ohm RG-59/U. I chose what I did because it worked consistently across 80-10 meters. The antenna radiating element and the radials are #20 teflon coated stranded electrical wire. The feedpoint/transformer is about 12-inches above ground. The radials are laying on top of the ground. I've measured complex impedance at the "shack end" of the coax with radiating elements ranging from about 20 feet to about 60 feet in length, and with various numbers and various radial lengths. With the end of the 42 feet and 9-inches of radiating element, up at about 38 feet above ground, and with the feed point/transformer at about 12 inches above ground, I saw extremes on 80 through 15 meters of: 3.75 MHz, I measure Z = 76 + j1 (SWR about 1.5:1) 14.175 MHz, I measure Z = 37 - j2 ( SWR about 1.4:1) Ten meters was not quite as good using a 42-foot 9-inch length of wire and 15 foot radials. But, it was quite acceptable for a portable antenna. At 28.5 MHz, I measure Z = 51 + j18 (SWR about 1.4:1) 29.0 MHz, I measure Z = 77 + j9 (SWR about 1.6:1) 29.5 MHz, I measure Z = 102 - j10 (SWR about 2.1:1) Each band was measured across the US non-WARC frequency extremes on 80/75, 40. 20. 15, and 10 meters. I was surprised when I was first testing these antennas early last week. Ten and 15 meters were both open to Europe and Scandinavia from here in the mountains of West Virginia on the vertical antennas. Using my little Ten Tec Argonaut 505 at about 3 watts SSB PEP, I made a number of contacts on both 10 and 15. I couldn't even hear these signals on my 137 foot doublet. I am presently writing that off to propagation variations. Enough for now. But, this may be food for thought. According to all the the initial writings I could find about these antennas, they should require antenna tuners to provide a reasonable 50 Ohm match to a transceiver. By doing the optimizations I did, I am not using them with a tuner. For comparison purposes, I am using my 137 foot ladder-line fed doublet antenna through an optimized coaxial choke per-band, and a properly tuned L-Network to provide a 50 Ohm impedance to my transceivers. I've also been using a single coil Z-matching link-coupled balanced tuner with the 137 foot doublet. Other than the Z-network being a lot narrower in bandwidth, I cannot tell a difference between the two tuners when used with the doublet. The weather is beautiful here in the West Virginia mountains. I'm going fishing.