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#1
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![]() I am interested in operation primarily on 160, 80, and 40. I have space for a full-size dipole for 160 but I cannot get it up very high, maybe 30 feet, higher than that only at great expense and with great difficulty. I will likely put up a 160-meter dipole at 30 feet and feed it with ladder line and a tuner, and use it for NVIS work on 160-40. For DX, though, I'm wondering if I will be happy with a vertical such as the Voyager DX from Gap Antennas, or if I should bite the bullet and go to the expense and difficulty of getting the dipole up 60-80 feet (which still won't be very high, compared with a wavelength, at 160 or 80). What's your advice? |
#2
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What's your advice?
Get a copy of ON4UN's low band DXing. Search the Topband archives antennas. Measure/estimate your ground conductivity and permittivity and get comfortable with a modeling program. And finally, experiment. I don't mean to be glib but there's really no quick answer to what antenna you'd be happy with for DX on 40,80 and 160. 30 feet for a horizontal antenna *is* too low, generally. Maybe someone can comment on the Voyager DX... I can't, specifically. Verticals are good, short verticals are compromises and must be treated with care. - - - - - - - - - This is what I use: http://www.n3ox.net/projects/sixtyvert I can certainly work more 40&80m DX on this than on the 30 foot high, 100 foot long centerfed wire I used to use on those bands. As far as 160m goes, this is the first time I can work 160 DX at all... 73, Dan |
#3
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Dan wrote:
http://www.n3ox.net/projects/sixtyvert I can certainly work more 40&80m DX on this than on the 30 foot high, 100 foot long centerfed wire I used to use on those bands. As far as 160m goes, this is the first time I can work 160 DX at all... 73, Dan Hmm... very interesting... and do-able. I've been thinking myself about erecting a vertical for 80/40 (but didn't want to waste my time). Thanks Dan! 73, Bryan WA7PRC |
#4
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On 11 Jan 2007 22:29:52 -0800, "
wrote: What's your advice? Get a copy of ON4UN's low band DXing. Search the Topband archives antennas. Measure/estimate your ground conductivity and permittivity and get comfortable with a modeling program. And finally, experiment. I don't mean to be glib but there's really no quick answer to what antenna you'd be happy with for DX on 40,80 and 160. 30 feet for a horizontal antenna *is* too low, generally. Maybe someone can comment on the Voyager DX... I can't, specifically. Verticals are good, short verticals are compromises and must be treated with care. - - - - - - - - - This is what I use: http://www.n3ox.net/projects/sixtyvert I can certainly work more 40&80m DX on this than on the 30 foot high, 100 foot long centerfed wire I used to use on those bands. As far as 160m goes, this is the first time I can work 160 DX at all... 73, Dan Your sixtyvert antenna has me rethinking my vertical plans. I have a forty foot utility pole laying on the ground while I plan the details for a taller vertical. In spite of my aversion to guys I think this pole is light enough to be workable for me. My current vertical is a 45 foot wire off the side of the tower tuned with an SGC-237. It seems to be working well in spite of a minimal ground. It appears to me that the guy anchors could be as simple as a few five gallon buckets of sand. I sure hate to pay that much shipping though! John Ferrell W8CCW |
#5
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On Fri, 12 Jan 2007 00:33:10 -0500, Rick
wrote: What's your advice? Hi Rick, Choose your poison. A 30 foot high 160M dipole is a notable ground hugging air cooled resistor. A GAP is probably worse. A combination of the two might be in order (which does NOT mean buy a GAP to do this). Erect a 30 foot vertical and top load it with what would have been the dipole. I will leave to others what could be done in higher bands (with one word of advice, GAPs don't usually perform very well on their lowest band(s), but have been to be reported as good verticals otherwise). 73's Richard Clark, KB7QHC |
#6
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![]() On Thu, 11 Jan 2007 22:36:23 -0800, Richard Clark wrote: A 30 foot high 160M dipole is a notable ground hugging air cooled resistor. A GAP is probably worse. Good morning, Richard. Actually, 30 feet is on the low side of "about right" on 160 and on the high side of "about right" on 80, for NVIS work, of which I do a lot. For DX, I agree that it's not of much use. And yet... My current antenna is an inverted V up about 35 feet in the center, 90 feet each leg, fed with ladder line. It started life as a 60-foot-high inverted V, full length for 160, in which configuration it worked rather well. Then a storm came by and knocked a tree down .... well, I digress... :-( I had earlier put up the inverted V via one of those "expensive and difficult" mechanisms I mentioned earlier (hired a 60-foot cherry picker and operator). I couldn't do that again, so I hoisted what was left of the antenna up to the top of my 35-foot tower, and trimmed the legs so that they would stay within the property line. Kept the ladder line feeder, and I tune it with an LDG RT-11 autotuner with the LDG balun. I use that antenna on all bands including 160, with a Yaesu FT-817 running a cloud-burning 5 watts, and it works amazingly well for the power level. But, as usual, I want more. :-) Thanks to you and others here for the feedback on the GAP. I REALLY wasn't up for spending almost half a grand for a vertical. |
#7
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Rick wrote:
I am interested in operation primarily on 160, 80, and 40. I have space for a full-size dipole for 160 but I cannot get it up very high, maybe 30 feet, higher than that only at great expense and with great difficulty. I will likely put up a 160-meter dipole at 30 feet and feed it with ladder line and a tuner, and use it for NVIS work on 160-40. For DX, though, I'm wondering if I will be happy with a vertical such as the Voyager DX from Gap Antennas, or if I should bite the bullet and go to the expense and difficulty of getting the dipole up 60-80 feet (which still won't be very high, compared with a wavelength, at 160 or 80). What's your advice? Hi Rick, As someone has said get a copy of ON4UN's Low band dxing.. I would not particularly recommend the Gap Antenna for Low Bands. Than being said if you and put out a decent radial system for dx Transmitting anyway I'd say you want some sort of vertical. Why not try a Inverted L. Try to get as much vertical as possible. Base tune it with a matching network- The SGC line works well for that application. you can read more about Inverted L's in Cebik's write up at: http://www.cebik.com/wire/ltv.html Good Luck 73, Dave Kc1di |
#8
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Rick wrote:
What's your advice? Check out the Inverted-L antenna. Also check the vertical Vs horizontal noise level at your QTH. My 40m vertical had 2 S-units higher noise than my 80m dipole rendering it useless for weak signal DX. -- 73, Cecil http://www.w5dxp.com |
#9
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On Fri, 12 Jan 2007 13:57:24 GMT, Cecil Moore
wrote: Check out the Inverted-L antenna. Doesn't the horizontal part of the inverted L need to be as high as possible for best results? I'd run into the same problems I'm running into in putting a dipole or inverted V up high enough. Also check the vertical Vs horizontal noise level at your QTH. My 40m vertical had 2 S-units higher noise than my 80m dipole rendering it useless for weak signal DX. I have a fairly high noise level around here on any of the horizontal antennas I've tried. But, I have an MFJ-1026 "Deluxe Noise Canceling Signal Enhancer" :-) that does an amazing job of cutting down the noise IF the noise is primarily from one general direction (which seems to be the case around here although I haven't been able to pinpoint it). That's one of the reasons I wanted to try some kind of a vertical and see how that worked. I read somewhere that ground mounted verticals with radials on or buried in the ground tend to be noisier. Is that true? That's one of the reasons I was considering the GAP Voyager DX... doesn't require an extensive radial system. |
#10
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Rick wrote:
Doesn't the horizontal part of the inverted L need to be as high as possible for best results? I'd run into the same problems I'm running into in putting a dipole or inverted V up high enough. Not exactly. Make the vertical section of the Inv-L as long as feasible. The vertical section is the highest current section and therefore has the greatest effect. Or instead of an Inv-L, make it a T antenna with a vertical section and a symmetrical top hat. The symmetrical top hat doesn't do much radiating. Here's what EZNEC says using VERT1.ez as the reference. 40m 33' Vert1 has -0.04 dBi gain omnidirectional. 16.5'-16.5'Inv-L has 1.04 dBi gain with some directivity. 16.5'-23.5' T antenna has 0.19 dBi gain omnidirectional. Note: 16.5' = vertical, 23.5' = horizontal top hat. Performance wise, I don't think you could tell the real vertical from the T except for the T's lower feedpoint impedance. -- 73, Cecil, http://www.qsl.net/w5dxp |
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