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#1
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I constructed an extended double zepp for
10 meters out of #12 solid house wire . I didn't have any ladder line laying around so I decided to make my own but all I had was some #10 stranded wire. I made the spacers 1" apart and and put about one per foot and the total feedling is approximately 25 ft. and it's going through an MFJ 941E Versatuner . I can't get my SWR's below 2 . I'm sure there are a lot of varibles here but I was hoping someone could point me in the right direction.My first guess is that I should have used the #12 for the feedline and the #10 for the antenna .. Thanks in advance , Will |
#2
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On Jul 15, 9:41 am, "Amerigo Vespucci" wrote:
I constructed an extended double zepp for 10 meters out of #12 solid house wire . I didn't have any ladder line laying around so I decided to make my own but all I had was some #10 stranded wire. I made the spacers 1" apart and and put about one per foot and the total feedling is approximately 25 ft. and it's going through an MFJ 941E Versatuner . I can't get my SWR's below 2 . I'm sure there are a lot of varibles here but I was hoping someone could point me in the right direction.My first guess is that I should have used the #12 for the feedline and the #10 for the antenna . Thanks in advance , Will Seems kind of strange the tuner would not match it.. The spacing probably has more effect on the feedline Z than the wire diameter. Shouldn't really be that critical. The wider the spacing, the higher the Z.. I guess you could try a different length of line.. Or scrounge up some other ladder line, maybe with a different length. Even 300 TV line would be ok if it's not wet. Myself, I used to feed them with coax, and coax series transformers. I imagine you could also feed with coax and use twin matching coils at the feedpoint for both sides of the element. Same as matching a 5/8 GP, you are just doing the same with a complete antenna. I've never tried it, but it should work. MK |
#3
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![]() wrote in message ups.com... On Jul 15, 9:41 am, "Amerigo Vespucci" wrote: I constructed an extended double zepp for 10 meters out of #12 solid house wire . I didn't have any ladder line laying around so I decided to make my own but all I had was some #10 stranded wire. I made the spacers 1" apart and and put about one per foot and the total feedling is approximately 25 ft. and it's going through an MFJ 941E Versatuner . I can't get my SWR's below 2 . I'm sure there are a lot of varibles here but I was hoping someone could point me in the right direction.My first guess is that I should have used the #12 for the feedline and the #10 for the antenna . Thanks in advance , Will Seems kind of strange the tuner would not match it.. The spacing probably has more effect on the feedline Z than the wire diameter. Shouldn't really be that critical. The wider the spacing, the higher the Z.. I guess you could try a different length of line.. Or scrounge up some other ladder line, maybe with a different length. Even 300 TV line would be ok if it's not wet. Myself, I used to feed them with coax, and coax series transformers. I imagine you could also feed with coax and use twin matching coils at the feedpoint for both sides of the element. Same as matching a 5/8 GP, you are just doing the same with a complete antenna. I've never tried it, but it should work. MK The way I understood it was the best way to feed it was with ladderline or something equal to it. I looked at the wireman website and saw their 450 ohm ladderline is only like 26 cents a foot so I'll order 80 feet of it and send the antenna up higher and take it from there. The reason I built the EDZ is it has 3 db over a dipole and it will also work for other bands with a tuner.Another reason I made the EDZ is a real estate issue(lacking) so something monsterous would be out of the question, but hey that's what makes ameteur radio such a great hobby,the experimentation that goes along with it. |
#4
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On Sun, 15 Jul 2007 14:41:33 GMT, "Amerigo Vespucci"
wrote: I constructed an extended double zepp for 10 meters out of #12 solid house wire . I didn't have any ladder line laying around so I decided to make my own but all I had was some #10 stranded wire. I made the spacers 1" apart and and put about one per foot and the total feedling is approximately 25 ft. and it's going through an MFJ 941E Versatuner . I can't get my SWR's below 2 . I'm sure there are a lot of varibles here but I was hoping someone could point me in the right direction.My first guess is that I should have used the #12 for the feedline and the #10 for the antenna . Thanks in advance , Will For what it's worth, a graph in one of my older ARRL antenna books says #10 wire at 1-inch spacing should have a characteristic impedance a little under 400 ohms. bob k5qwg |
#5
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On Sun, 15 Jul 2007 15:53:48 GMT, "Amerigo Vespucci" wrote:
snip The way I understood it was the best way to feed it was with ladderline or something equal to it. I looked at the wireman website and saw their 450 ohm ladderline is only like 26 cents a foot so I'll order 80 feet of it and send the antenna up higher and take it from there. The reason I built the EDZ is it has 3 db over a dipole and it will also work for other bands with a tuner.Another reason I made the EDZ is a real estate issue(lacking) so something monsterous would be out of the question, but hey that's what makes ameteur radio such a great hobby,the experimentation that goes along with it. Hi Amerigo, The transmission line you constucted should work just fine--don't go buying any more line, because the difference will be insignificant. And another point you should be aware of is that the 3dB improvement using the EDZ is only in the direction at right angles to the antenna, because the broadside lobe of the EDZ is somewhat narrower than that of the 1/2 wave dipole, and as a result, the gain in all other directions is LESS than that of the 1/2 wave dipole. Walt, W2DU |
#6
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![]() "Walter Maxwell" wrote in message ... On Sun, 15 Jul 2007 15:53:48 GMT, "Amerigo Vespucci" wrote: snip The way I understood it was the best way to feed it was with ladderline or something equal to it. I looked at the wireman website and saw their 450 ohm ladderline is only like 26 cents a foot so I'll order 80 feet of it and send the antenna up higher and take it from there. The reason I built the EDZ is it has 3 db over a dipole and it will also work for other bands with a tuner.Another reason I made the EDZ is a real estate issue(lacking) so something monsterous would be out of the question, but hey that's what makes ameteur radio such a great hobby,the experimentation that goes along with it. Hi Amerigo, The transmission line you constucted should work just fine--don't go buying any more line, because the difference will be insignificant. I tried pruning the antenna a couple of inches and fiddled with the feeder line and manged to get mr SWR's down below two but with a tuner I'm still not happy. My rig is a Kenwood TS 530S so the finals are a little more forgiving but I still wanna mess with it some more when the weather cools a bit. Thnks all for you help I'll update you later on with whatever progress I get. And another point you should be aware of is that the 3dB improvement using the EDZ is only in the direction at right angles to the antenna, because the broadside lobe of the EDZ is somewhat narrower than that of the 1/2 wave dipole, and as a result, the gain in all other directions is LESS than that of the 1/2 wave dipole. Walt, W2DU |
#7
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Correction,my rig is a Kenwood 520SE
"Amerigo Vespucci" wrote in message news:6Vtmi.4451$225.335@trndny03... "Walter Maxwell" wrote in message ... On Sun, 15 Jul 2007 15:53:48 GMT, "Amerigo Vespucci" wrote: snip The way I understood it was the best way to feed it was with ladderline or something equal to it. I looked at the wireman website and saw their 450 ohm ladderline is only like 26 cents a foot so I'll order 80 feet of it and send the antenna up higher and take it from there. The reason I built the EDZ is it has 3 db over a dipole and it will also work for other bands with a tuner.Another reason I made the EDZ is a real estate issue(lacking) so something monsterous would be out of the question, but hey that's what makes ameteur radio such a great hobby,the experimentation that goes along with it. Hi Amerigo, The transmission line you constucted should work just fine--don't go buying any more line, because the difference will be insignificant. I tried pruning the antenna a couple of inches and fiddled with the feeder line and manged to get mr SWR's down below two but with a tuner I'm still not happy. My rig is a Kenwood TS 530S so the finals are a little more forgiving but I still wanna mess with it some more when the weather cools a bit. Thnks all for you help I'll update you later on with whatever progress I get. And another point you should be aware of is that the 3dB improvement using the EDZ is only in the direction at right angles to the antenna, because the broadside lobe of the EDZ is somewhat narrower than that of the 1/2 wave dipole, and as a result, the gain in all other directions is LESS than that of the 1/2 wave dipole. Walt, W2DU |
#8
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Amerigo Vespucci wrote:
The way I understood it was the best way to feed it was with ladderline or something equal to it. Did anyone tell you that the matching section needs to be about 0.2 wavelength? -- 73, Cecil http://www.w5dxp.com |
#9
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![]() "Cecil Moore" wrote in message t... Amerigo Vespucci wrote: The way I understood it was the best way to feed it was with ladderline or something equal to it. Did anyone tell you that the matching section needs to be about 0.2 wavelength? Explain? -- 73, Cecil http://www.w5dxp.com |
#10
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On Sun, 15 Jul 2007 18:43:14 GMT, "Amerigo Vespucci" wrote:
I tried pruning the antenna a couple of inches and fiddled with the feeder line and manged to get mr SWR's down below two but with a tuner I'm still not happy. My rig is a Kenwood TS 530S so the finals are a little more forgiving Amerigo, Are you expecting that if you get the SWR lower your finals will run cooler? Because the reflected power into them will be less? (Hey Walt !! We need you) Rick K2XT |
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