The only wire dipole with gain is the Extended Double Zepp ("EDZ"). It has 3dbd gain or doubles your power. I studied the possibilities on the internet. I wondered if I could do it in a inverted vee since I only had one 35 foot mast available . So I set out to test this puppy.
Turns out this antenna has 5/8 wavelength on each side of the center insulator. 1005 /frq X.64 It is then fed with a combination of 450 ohm twin lead and 72 ohm RG6 coax to the rig. Use a 4:1 current balun at the joiner of the coax to the section of 450 ohm twin lead. The conventional teaching on the length of twin lead is too dogmatic. You will see all these formulas for the lengths of these enormously long sections of 450 OHM ladder line. They may work but I don't believe the ladder line is radiating-- The 5/8 dipole radiators are radiating on each side of the feed point just like any dipole. Does your feed line radiate on your dipole? I hope not. The Ladder line sets up the match to the 72 ohm coax ( you can use 50 ohm) with the 4:1 balun. I don't care how long that ladder line is.
I only had about 10 feet of Ladder line anyway so let's try that!! I built mine for 30 meters . With trimming to resonance it turned out to be about 69 feet (note that is pretty far off maybe because of the shorter ladder line but keep trimming and adjusting based on that good 'ol Analyzer) on each half of the dipole section. This is why the formula above is 1005/ fq x .64. The ladder line did its matching job with the balun and the EDZ on 30 was a GUN ! I elevated each end using the fiber glass quad spreaders lashed to tee posts and raising the ends to about 14 feet. I use pulleys at the top on the end supports to raise them up and down for quick adjustments. I use a pulley system on the 35 foot center mast.
The results were astonishing. Best wire antenna I ever made and definite gain as advertised. !! Weak Dx came back in one call in small pileups. What a success!! Let me tell you what a success it was. When FT5ZM (Amsterdam Island in the Indian ocean) came up on 30 meters on the 27th of January 2014 , the pile up was expansive. REALLY!!! At 02:26Z I qsoed after two (2) calls with 200 watts. Now you and I both know the luck involved to go 12,269 miles in a raging pile up in two calls-- But I'm just saying, I got there.
But what about 17 meters? While 17 would load on the 30 meter EDZ for some reason-- It had no gain. I wanted this gain on 17!!! ONE ONE FEED SYSTEM!! so I cut the dipole radiators at 5/8 wave on each side and soldered to the center insulator point .The 450 ohm ladder line now fed both the EDZs! (and of course the single 50 ohm coax ) . Well, what do you know? The 17 meter EDZ worked great!! ( you have to trim to resonance) I tied its end to different tie off points to avoid interaction.
I love the gain and simplicity of the EDZ . I have phased verticals on 40 for DX but this EDZ antenna has great potential on 40. Its draw back is it is 81 feet on each side-- (Yuk) Give it a try.
I must add that the two band idea on 17( with the 30) did not out perform either a full wave loop on 17 or a freestanding 17 meter edz flat top at 30 feet. The free standing 17 meter edz is 66 feet long . My two element quad loop is 3 to 5 db better that the EDZ on rx,in my opinion. It has 7.5 dbd gain and I have an article on it.
I want to tell you that I duplicated this 30 meter antenna. I lost the first one in wind and ice so I bought new size 14 insulated wire and raised the system 5 feet. Again it came out to about 70 feet per side to tune to resonance but magnificent results again.
I want to emphasize the utility of big rolls of weed eater line used as guys, insulators and tie off lines. I get 1000 feet for about $40. Try to get .90 or larger. Yes, it deteriorates in the ultra violet sun light. The half life ifs about 3 years. So change it when you need to.
FLASH!!! The old 30 meter EDZ was destroyed in an ice storm. I replaced it with a straight 17 meter EDZ. Same formula. What a wonderful antenna. But the big new was the rebuild of the 30 meter edz. Apex only 30 feet . It was 62 feet on the radiators this time and the 450 ladder was 10.2 feet. The ends are 25 feet off the ground. This time 50 ohm coax . It is awesome. Tests are great against my half sloper 5/8th wave. on RBN. I see some great lobes that are better than others..But one fantastic plus was absolute resonances as a dipole on 80 meter cw!! It makes perfect sense!! 124 feet of radiator plus the ladder line!! Dropped is right in as an 80m dipole. It also is resonant on 15 meters . With tuner on rig-- 40, 20, 12, 10-- no problem.
Let me know how you come out on your EDZ and feel free to email me at mikew5zo@clear.net if you need a sounding board.
Here you can see the two dipoles are attached to the 10 feet of ladder line at the top of the mast
Here is the current balun at the bottom of the ladder line on the two band edz
Between you and me ,I go back to my work on the "fan Vertical "and apply "W5ZO's Law", that if the feed point impedance is 50 to 75 ohms, and the rf can find a resonant radiator (or proper multiple of one), it doesn't matter how many radiators you have on the antenna , all of the rf goes to that resonator.(actually a hypothesis) .
At Christmas we went to Ruidoso New Mexico and I pre built a 20 meter EDZ (only 7 feet of 450 ohm ladder line.) . We had large pine trees on the property so I used a sling shot and got a good shot of fishing line through the tree at about 32 feet.( I tie the fishing line to a 3/4 inch nut to act as the projectile) I hiked up the center of the EDzepp with weed eater line that I pulled through with the fishing line and tied off the lines inverted vee using weed eater line as usual as a wonderful insulator. The swr worked like it did at home when I built it. 1.1 @ 14.020. I used 80 feet of 70 ohm RG6 to the balun. (look at the loss on that stuff!! beats LMR!!)
The first thing I learned was the while resonant on 20 ,I was able to use an internal tuner (Icom 756P3) and put out a heck of a signal on 15/12/10 meters. Not so good on 17.
THE 17 meter EDZ.
I wanted to do a free standing EDZ for 17 meters and test it against a full wave delta loop at 30 feet. I built the free standing 17 meter EDZ at 36 feet. Each end came down to 15 feet in an inverted vee. Once again,I used 10 feet om 450 ohm Ladder line to a 4:1 balun. Each side resonated for @ 36.3 feet in this configuration . As you may know, I use 75 ohm RG6 because of its extremely low loss ( comparable to LMR) . Now, I would test the two antennas on Reverse Beacon Network ( See my page on using RBM internet to compare two antenna). I first sent cq on the EDZ at 00:06 UTC on 18070.9 . You will see those reports coming back followed by the the same stations coming back on internet on my cq @ 00:07 UTC at 18068.9 on the 17 meter delta loop. You can see the difference for yourself. It was measurably better on the EDZ just as it should be with 3 dbd . The two antenna are on different frequencies so you can differentiate between them.
Here is another RBN confirmation. HERE The 17 meter EDZ is tested first at 21:41z on 18086.9 mhz with a "CQ " for 30 seconds. ( see bottom first ) then at 21:22z the delta loops is used on 18088.3.
Turns out this antenna has 5/8 wavelength on each side of the center insulator. 1005 /frq X.64 It is then fed with a combination of 450 ohm twin lead and 72 ohm RG6 coax to the rig. Use a 4:1 current balun at the joiner of the coax to the section of 450 ohm twin lead. The conventional teaching on the length of twin lead is too dogmatic. You will see all these formulas for the lengths of these enormously long sections of 450 OHM ladder line. They may work but I don't believe the ladder line is radiating-- The 5/8 dipole radiators are radiating on each side of the feed point just like any dipole. Does your feed line radiate on your dipole? I hope not. The Ladder line sets up the match to the 72 ohm coax ( you can use 50 ohm) with the 4:1 balun. I don't care how long that ladder line is.
I only had about 10 feet of Ladder line anyway so let's try that!! I built mine for 30 meters . With trimming to resonance it turned out to be about 69 feet (note that is pretty far off maybe because of the shorter ladder line but keep trimming and adjusting based on that good 'ol Analyzer) on each half of the dipole section. This is why the formula above is 1005/ fq x .64. The ladder line did its matching job with the balun and the EDZ on 30 was a GUN ! I elevated each end using the fiber glass quad spreaders lashed to tee posts and raising the ends to about 14 feet. I use pulleys at the top on the end supports to raise them up and down for quick adjustments. I use a pulley system on the 35 foot center mast.
The results were astonishing. Best wire antenna I ever made and definite gain as advertised. !! Weak Dx came back in one call in small pileups. What a success!! Let me tell you what a success it was. When FT5ZM (Amsterdam Island in the Indian ocean) came up on 30 meters on the 27th of January 2014 , the pile up was expansive. REALLY!!! At 02:26Z I qsoed after two (2) calls with 200 watts. Now you and I both know the luck involved to go 12,269 miles in a raging pile up in two calls-- But I'm just saying, I got there.
But what about 17 meters? While 17 would load on the 30 meter EDZ for some reason-- It had no gain. I wanted this gain on 17!!! ONE ONE FEED SYSTEM!! so I cut the dipole radiators at 5/8 wave on each side and soldered to the center insulator point .The 450 ohm ladder line now fed both the EDZs! (and of course the single 50 ohm coax ) . Well, what do you know? The 17 meter EDZ worked great!! ( you have to trim to resonance) I tied its end to different tie off points to avoid interaction.
I love the gain and simplicity of the EDZ . I have phased verticals on 40 for DX but this EDZ antenna has great potential on 40. Its draw back is it is 81 feet on each side-- (Yuk) Give it a try.
I must add that the two band idea on 17( with the 30) did not out perform either a full wave loop on 17 or a freestanding 17 meter edz flat top at 30 feet. The free standing 17 meter edz is 66 feet long . My two element quad loop is 3 to 5 db better that the EDZ on rx,in my opinion. It has 7.5 dbd gain and I have an article on it.
I want to tell you that I duplicated this 30 meter antenna. I lost the first one in wind and ice so I bought new size 14 insulated wire and raised the system 5 feet. Again it came out to about 70 feet per side to tune to resonance but magnificent results again.
I want to emphasize the utility of big rolls of weed eater line used as guys, insulators and tie off lines. I get 1000 feet for about $40. Try to get .90 or larger. Yes, it deteriorates in the ultra violet sun light. The half life ifs about 3 years. So change it when you need to.
FLASH!!! The old 30 meter EDZ was destroyed in an ice storm. I replaced it with a straight 17 meter EDZ. Same formula. What a wonderful antenna. But the big new was the rebuild of the 30 meter edz. Apex only 30 feet . It was 62 feet on the radiators this time and the 450 ladder was 10.2 feet. The ends are 25 feet off the ground. This time 50 ohm coax . It is awesome. Tests are great against my half sloper 5/8th wave. on RBN. I see some great lobes that are better than others..But one fantastic plus was absolute resonances as a dipole on 80 meter cw!! It makes perfect sense!! 124 feet of radiator plus the ladder line!! Dropped is right in as an 80m dipole. It also is resonant on 15 meters . With tuner on rig-- 40, 20, 12, 10-- no problem.
Let me know how you come out on your EDZ and feel free to email me at mikew5zo@clear.net if you need a sounding board.
Here you can see the two dipoles are attached to the 10 feet of ladder line at the top of the mast
Between you and me ,I go back to my work on the "fan Vertical "and apply "W5ZO's Law", that if the feed point impedance is 50 to 75 ohms, and the rf can find a resonant radiator (or proper multiple of one), it doesn't matter how many radiators you have on the antenna , all of the rf goes to that resonator.(actually a hypothesis) .
At Christmas we went to Ruidoso New Mexico and I pre built a 20 meter EDZ (only 7 feet of 450 ohm ladder line.) . We had large pine trees on the property so I used a sling shot and got a good shot of fishing line through the tree at about 32 feet.( I tie the fishing line to a 3/4 inch nut to act as the projectile) I hiked up the center of the EDzepp with weed eater line that I pulled through with the fishing line and tied off the lines inverted vee using weed eater line as usual as a wonderful insulator. The swr worked like it did at home when I built it. 1.1 @ 14.020. I used 80 feet of 70 ohm RG6 to the balun. (look at the loss on that stuff!! beats LMR!!)
The first thing I learned was the while resonant on 20 ,I was able to use an internal tuner (Icom 756P3) and put out a heck of a signal on 15/12/10 meters. Not so good on 17.
THE 17 meter EDZ.
I wanted to do a free standing EDZ for 17 meters and test it against a full wave delta loop at 30 feet. I built the free standing 17 meter EDZ at 36 feet. Each end came down to 15 feet in an inverted vee. Once again,I used 10 feet om 450 ohm Ladder line to a 4:1 balun. Each side resonated for @ 36.3 feet in this configuration . As you may know, I use 75 ohm RG6 because of its extremely low loss ( comparable to LMR) . Now, I would test the two antennas on Reverse Beacon Network ( See my page on using RBM internet to compare two antenna). I first sent cq on the EDZ at 00:06 UTC on 18070.9 . You will see those reports coming back followed by the the same stations coming back on internet on my cq @ 00:07 UTC at 18068.9 on the 17 meter delta loop. You can see the difference for yourself. It was measurably better on the EDZ just as it should be with 3 dbd . The two antenna are on different frequencies so you can differentiate between them.
| de | dx | freq | cq/dx | snr | speed | time |
| W3UA |  W5ZO | 18068.8 | CW CQ [LoTW] | 18 dB | 24 wpm | 0007z 22 Feb |
| VE7AB | W5ZO | 18068.9 | CW CQ [LoTW] | 24 dB | 24 wpm | 0007z 22 Feb |
| K2NNY | W5ZO | 18068.8 | CW CQ [LoTW] | 12 dB | 24 wpm | 0007z 22 Feb |
| K1TTT | W5ZO | 18069.0 | CW CQ [LoTW] | 20 dB | 24 wpm | 0007z 22 Feb |
| KM3T | W5ZO | 18068.9 | CW CQ [LoTW] | 6 dB | 24 wpm | 0006z 22 Feb |
| K7EG | W5ZO | 18068.9 | CW CQ [LoTW] | 16 dB | 24 wpm | 0006z 22 Feb |
| KU7T | W5ZO | 18068.9 | CW CQ [LoTW] | 6 dB | 24 wpm | 0006z 22 Feb |
| WZ7I | W5ZO | 18068.9 | CW CQ [LoTW] | 23 dB | 24 wpm | 0006z 22 Feb |
| VE7AB | W5ZO | 18070.9 | CW CQ [LoTW] | 22 dB | 24 wpm | 0006z 22 Feb |
| K2NNY | W5ZO | 18070.8 | CW CQ [LoTW] | 11 dB | 24 wpm | 0006z 22 Feb |
| K1TTT | W5ZO | 18071.0 | CW CQ [LoTW] | 24 dB | 24 wpm | 0006z 22 Feb |
| KM3T | W5ZO | 18070.9 | CW CQ [LoTW] | 13 dB | 24 wpm | 0005z 22 Feb |
| K7EG | W5ZO | 18070.9 | CW CQ [LoTW] | 5 dB | 24 wpm | 0005z 22 Feb |
| KU7T | W5ZO | 18070.9 | CW CQ [LoTW] | 13 dB | 24 wpm | 0005z 22 Feb |
| WZ7I | W5ZO | 18070.9 | CW CQ [LoTW] | 26 dB | 24 wpm | 0005z 22 Feb |
| W3UA | W5ZO | 18070.8 | CW CQ [LoTW] | 29 dB | 24 wpm | 0005z 22 Feb |
Here is another RBN confirmation. HERE The 17 meter EDZ is tested first at 21:41z on 18086.9 mhz with a "CQ " for 30 seconds. ( see bottom first ) then at 21:22z the delta loops is used on 18088.3.
Using the same station just one minute apart negates or at least mitigates the qsb factor. I found EDZ nulls to the north on west . Look at K7EG return a 16 db S/n on the Delta and 4 db S/N on the EDZ. Also look a VE 7AB with 27 DB on the Delta Loop and 12 db on the EDZ. ( The EDZ will have some lobes) But then look at the rest. The total for the remaining 10 stations was a whopping 55 db S/N!! Look at N8MSA ! 3 db on the Delta and 13 on the EDZ. Look at WZ7I. 21 db on the Delta and 30 on the EDZ. That is a whopping 2 S units. W4AX , 11 db S/N on the Delta and 20 big ones on the EDZ. !! That, my fellow hams, is 3 S units. The EDZ out performs the Delta Loop. Again the 17 EDZ is only 6 feet higher than the APEX on the Delta loop.
The 4:1 balun with cut and trim flattened the SWR 1:1.
These EDZs are worth your effort. Where else do you get 3 db gain (dbd) with a dipole? Good luck. Email me for suggestions. w5zo@arrl.net
| N8MSA | W5ZO | 18088.3 | CW CQ [LoTW] | 3 dB | 24 wpm | 2142z 26 Feb |
| K2NNY | W5ZO | 18088.1 | CW CQ [LoTW] | 7 dB | 24 wpm | 2142z 26 Feb |
| W2AXR | W5ZO | 18088.3 | CW CQ [LoTW] | 17 dB | 24 wpm | 2142z 26 Feb |
| WZ7I | W5ZO | 18088.2 | CW CQ [LoTW] | 21 dB | 24 wpm | 2142z 26 Feb |
| WZ7I | W5ZO | 18088.2 | CW CQ [LoTW] | 4 dB | 24 wpm | 2142z 26 Feb |
| W4AX | W5ZO | 18088.2 | CW CQ [LoTW] | 11 dB | 24 wpm | 2142z 26 Feb |
| N6TV | W5ZO | 18088.2 | CW CQ [LoTW] | 19 dB | 24 wpm | 2142z 26 Feb |
| W3UA | W5ZO | 18088.2 | CW CQ [LoTW] | 22 dB | 24 wpm | 2142z 26 Feb |
| KM3T | W5ZO | 18088.2 | CW CQ [LoTW] | 8 dB | 24 wpm | 2142z 26 Feb |
| KU7T | W5ZO | 18088.2 | CW CQ [LoTW] | 11 dB | 24 wpm | 2142z 26 Feb |
| AA4VV | W5ZO | 18088.2 | CW CQ [LoTW] | 16 dB | 24 wpm | 2142z 26 Feb |
| K7EG | W5ZO | 18088.2 | CW CQ [LoTW] | 16 dB | 24 wpm | 2142z 26 Feb |
| W3OA | W5ZO | 18088.3 | CW CQ [LoTW] | 17 dB | 24 wpm | 2142z 26 Feb |
| VE7AB | W5ZO | 18088.3 | CW CQ [LoTW] | 27 dB | 24 wpm | 2142z 26 Feb |
| AA4VV | W5ZO | 18086.9 | CW CQ [LoTW] | 27 dB | 24 wpm | 2141z 26 Feb |
| KP3Z | W5ZO | 18087.0 | CW CQ [LoTW] | 6 dB | 24 wpm | 2141z 26 Feb |
| K7EG | W5ZO | 18086.9 | CW CQ [LoTW] | 4 dB | 24 wpm | 2141z 26 Feb |
| N2QT | W5ZO | 18087.0 | CW CQ [LoTW] | 7 dB | 24 wpm | 2141z 26 Feb |
| W3OA | W5ZO | 18087.0 | CW CQ [LoTW] | 22 dB | 24 wpm | 2141z 26 Feb |
| VE7AB | W5ZO | 18087.0 | CW CQ [LoTW] | 12 dB | 24 wpm | 2141z 26 Feb |
| N8MSA | W5ZO | 18087.0 | CW CQ [LoTW] | 13 dB | 24 wpm | 2141z 26 Feb |
| K2NNY | W5ZO | 18086.8 | CW CQ [LoTW] | 9 dB | 24 wpm | 2141z 26 Feb |
| W2AXR | W5ZO | 18087.0 | CW CQ [LoTW] | 17 dB | 24 wpm | 2141z 26 Feb |
| WZ7I | W5ZO | 18086.9 | CW CQ [LoTW] | 7 dB | 24 wpm | 2141z 26 Feb |
| WZ7I | W5ZO | 18086.9 | CW CQ [LoTW] | 30 dB | 24 wpm | 2141z 26 Feb |
| W4AX | W5ZO | 18086.9 | CW CQ [LoTW] | 20 dB | 24 wpm | 2141z 26 Feb |
| N6TV | W5ZO | 18086.9 | CW CQ [LoTW] | 17 dB | 24 wpm | 2141z 26 Feb |
| KM3T | W5ZO | 18086.9 | CW CQ [LoTW] | 17 dB | 24 wpm | 2141z 26 Feb |
These EDZs are worth your effort. Where else do you get 3 db gain (dbd) with a dipole? Good luck. Email me for suggestions. w5zo@arrl.net
