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#62
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Dipoles, why height matters
On 11/23/2014 12:20 PM, John S wrote:
On 11/21/2014 6:41 PM, Jerry Stuckle wrote: On 11/21/2014 5:47 PM, Ian Jackson wrote: In message , Wayne writes wrote in message ... For those that do not have a firm understanding of what the chart of dipole height over ground shows, I offer the following explanation. The charts show, for a dipole antenna at various heights in wavelengths over perfect, very good, average, and extremely poor ground, the gain and elevation angle of the antenna main lobe. The main lobe is where the majority of the energy is radiated. To understand what the charts mean in the real world, first you have to understand a little bit about propagation of RF. For a dipole antenna, there are two modes of propagation that are relevant, and those are NVIS (Near Vertical Incidence Skywave) and skywave which is sometimes called skip. Both modes depend on the RF being reflected or refracted back toward Earth by the ionosphere. For NVIS mode, the RF is directed straight up, that is an elevation angle close to 90 degrees is desired. The range of NVIS communications is on the order of 50 - 650 km, depending on the state of the ionosphere. The amateur bands where this is effective is limited primarily to the 160M to 40M band, again depending on the state of the ionosphere. It is not impossible to have NVIS communications on the higher bands, just much less probable to happen. For skywave mode, a low elevation mode is desired. Most of the literature recommends angles of 30 degees or less. In this mode the RF "bounces" at more obtuse angles, and with good conditions in the ionosphere, more than once, providing communication over global distances. Skywave depends heavily on the condition of the ionosphere and during sunspot peaks often occurs well past 10M. Now since a dipole with a main lobe at 90 degrees still has some gain at low angles, though it can be 20 to 60 dB down from the main lobe, when conditions are very good some stations can still be heard by skywave mode, though it is a rarity and can not be depended on. Conversely a dipole with a low elevation angle of the main lobe has some gain at very high angles and can occasionly hear stations by NVIS mode, but again it is a rarity. The bottom line of all this is that if you desire NVIS communications, you should mount your dipole at a height where the elevation angle is close to 90 degrees while if you desire long distance communications you should mount your dipole at a height where the elevation angle is less than 30 degrees, or higher if possible. If the required height is impractical at your location, then the alternative is a ground mounted vertical or a close to ground mounted ground plane antenna, which will have an elevation angle in the 20 degree range. Along the lines of a "testimonial"... I once lived in the center of a state that had an active 75 meter net. At one point I was asked to be one of the net control stations because of my consistent strong signals within the net. The secret? A 75 meter dipole at 20 feet with 100 watts. On longer paths, of course, the "big boys" kicked my butt big time. Despite the obvious theory, and over 50 years in amateur radio, I still find it hard to believe that, in real life, an 80m dipole at (say) 20' ever really outperforms (at any distance) one at (say) 100'. Given the choice, I know which one I would choose! I never said a dipole at 20' outperforms one at 100'. But I DID say a dipole at 20' does NOT necessarily "suck". It can be a good antenna, depending on a lot of other factors. I've also run dipoles - I got WAS on 75 meters from Iowa with an inverted VEE running from 50' to near ground. And I had a strong signal on the Iowa 75M SSB net. Doesn't sound like it "sucked" to me. If you two really have balls, you will get on Skype, look at each other, and hash out your differences there. Or, maybe become friends. It can happen! I don't make friends with trolls. And I'm not going to waste any time on Skype with him. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#63
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Dipoles, why height matters
On 11/23/2014 1:11 PM, wrote:
Jerry Stuckle wrote: On 11/22/2014 11:21 PM, wrote: Jerry Stuckle wrote: On 11/22/2014 9:18 PM, wrote: Jerry Stuckle wrote: On 11/22/2014 7:21 PM, wrote: Jerry Stuckle wrote: snip Once again you refuse to discuss the topic. Instead of admitting you are wrong, you are making ad hominim attacks. How like a troll. You have changed the topic so many times now I lose track. First it was the effects of antenna height in wavelengths. Then it was something about you not liking my response to someone who said their antenna sucked. I called your statement into question because you said any 80 meter antenna under 100' (a little over 1/4 wavelength) sucked. That's not quite what I said, but in any case ANY dipole mounted at less than 1/2 wavelength high will NOT perform as well for DX as a a dipole mounted 1/2 wave length high or higher. It is EXACTLY what you said - except for the parentheses, which I added. The whole point of which is that you used a less than optimal antenna for DX and then became outraged that someone dared to imply your antenna was less than perfect. That is NOT WHAT YOU SAID. Do I need to paste your exact words a *third time*? Is your memory that short? You are correct, it wasn't those exact words, but it was exactly that rephrased. Yes, and in rephrasing it, you completely changed the meaning. How like a troll. You are simply unable to accept the fact that something you had could have worked better, thus you rant and fume and go off on tangents. Where did I say something could not have worked better? Or are you trying to put words in my mouth, again? That's what trolls do, after all. Yes, you can copy and paste charts. But you don't UNDERSTAND them. Where is your explanation that you have been asked for many times now? I'm not going to waste my time on trying to teach a pig to sing. What means you have nothing to say about the charts other than your antenna worked so that must be the standard to which all other antennas should be compared. I am not going to waste my time on trying to teach a pig to sing. And any proof I provide will just be dismissed by you. Plus I NEVER said that my antenna must be the standard for other antennas. But that's another false claim by the troll. If you actually had anything factual to say you would have said it long ago so you could gloat in your superiority but the only thing you seem able to say is that I don't understand what I did. I did, and you discarded it because it disagreed with your fantasies. You have never said ANYTHING other than your antenna worked so that must be the standard to which all other antennas should be compared. Yea, right. Show me the proof, troll! Then it was something about you having a WAS thus proving your antenna was wonderful. Yes, I proved you were wrong with your statement about wavelengths. No, you just babbled nonsense about a WAS somehow magically says something about antenna gain and pattern. I gave you proof that you were wrong. But you just discard it because it violates your fantasies. You gave proof of nothing, just ranting rage about having a WAS, which I am beginning to doubt. ROFLMAO! Trying to change the subject again? Just like the troll you are. YOU are the one that keeps bringing up having a WAS as proof of how wonderful your antenna was. You're the one who keeps dismissing proof that the antenna worked. Tell me how to get WAS on 80 meters with an antenna that "sucks". People are eager to know. Anything that conducts, from a light bulb to a set of bed springs can act as an antenna and some contacts can be made; I've done it with both. Simply because something "works" says nothing about how well it works. OK, let's see YOU get WAS on 80 meters with a light bulb. You are simply unable to accept the fact that something you had could have worked better, thus you rant and fume and go off on tangents. Where did I say something could not have worked better? Or are you trying to put words in my mouth, again? That's what trolls do, after all. Then it was something about 80M and 6M being different when I said that signal reports do not measure antenna gain or pattern. You're the one who brought up 6M, not me. You STILL refuse understand that gain and pattern numbers for an antenna have meaning but awards go not, which was the ENTIRE POINT of the 6M statments. Oh, I understand all right. You're just a troll who keeps trying to change the subject when met with facts that match his fantasies. You STILL refuse understand that gain and pattern numbers for an antenna have meaning but awards do not, which was the ENTIRE POINT of the 6M statments. You fail to understand the awards are, in part, a measurement of *performance of your station*. That includes the antenna. Tell me how to get 80 meter WAS on a light bulb. After all, you claimed it works as an antenna! Anything that conducts, from a light bulb to a set of bed springs can act as an antenna and some contacts can be made; I've done it with both. Simply because something "works" says nothing about how well it works. Let's see you get WAS on 80 meters with a light bulb. You are simply unable to accept the fact that something you had could have worked better, thus you rant and fume and go off on tangents. Where did I say something could not have worked better? Or are you trying to put words in my mouth, again? That's what trolls do, after all. Which topic do you want? I haven't changed the topic at all. But you have tried to do so - several times. Oh, I forgot the one where you stupidly said that numbers expressed in wavelenths were not relevant to all dipoles. I never said that. Prove where I did. In response to Izur Kockenhan, Sun, 16 Nov 2014 06:18:04: "He thinks the charts he copies/pastes are the last word and apply to all dipoles." Which does not say the numbers expressed were not relevant. If you think the numbers are relevant, why do you continue to rant? You are simply unable to accept the fact that something you had could have worked better, thus you rant and fume and go off on tangents. Where did I say something could not have worked better? Or are you trying to put words in my mouth, again? That's what trolls do, after all. All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. You really have lost it. But I have the proof in writing that all of your claims about what I said are bunk. You can't lie your way out of it, troll. -- ================== Remove the "x" from my email address Jerry Stuckle ================== |
#64
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Dipoles, why height matters
Jerry Stuckle wrote:
All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. No, you went into a multipost rage over the implication something you did was less than perfect. -- Jim Pennino |
#65
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Dipoles, why height matters
Jerry Stuckle wrote:
ssnip All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. You went into a multipost rage when it was implied that something you did was less than perfect and you are still raging about it. -- Jim Pennino |
#66
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Dipoles, why height matters
Jerry Stuckle wrote:
On 11/23/2014 1:11 PM, wrote: Jerry Stuckle wrote: On 11/22/2014 11:21 PM, wrote: Jerry Stuckle wrote: On 11/22/2014 9:18 PM, wrote: Jerry Stuckle wrote: On 11/22/2014 7:21 PM, wrote: Jerry Stuckle wrote: snip Once again you refuse to discuss the topic. Instead of admitting you are wrong, you are making ad hominim attacks. How like a troll. You have changed the topic so many times now I lose track. First it was the effects of antenna height in wavelengths. Then it was something about you not liking my response to someone who said their antenna sucked. I called your statement into question because you said any 80 meter antenna under 100' (a little over 1/4 wavelength) sucked. That's not quite what I said, but in any case ANY dipole mounted at less than 1/2 wavelength high will NOT perform as well for DX as a a dipole mounted 1/2 wave length high or higher. It is EXACTLY what you said - except for the parentheses, which I added. The whole point of which is that you used a less than optimal antenna for DX and then became outraged that someone dared to imply your antenna was less than perfect. That is NOT WHAT YOU SAID. Do I need to paste your exact words a *third time*? Is your memory that short? You are correct, it wasn't those exact words, but it was exactly that rephrased. Yes, and in rephrasing it, you completely changed the meaning. No, I did not change the meanging. The bottom line is, and always has been, you went into a multipost rage because it was implied something you did was less than perfect. And you are still raging about it. -- Jim Pennino |
#67
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Dipoles, why height matters
On 2014-11-23 20:54:25 +0000, Jerry Stuckle said:
All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. He's already agreed with you that that was not an accurate assessment and didn't represent his overall judgement, just a careless reiteration of what someone else said; and that was about 4000 posts ago! -- Percy Picacity |
#68
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Dipoles, why height matters
On 11/23/2014 4:06 PM, wrote:
Jerry Stuckle wrote: All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. No, you went into a multipost rage over the implication something you did was less than perfect. Your proof? -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#69
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Dipoles, why height matters
On 11/23/2014 4:22 PM, Percy Picacity wrote:
On 2014-11-23 20:54:25 +0000, Jerry Stuckle said: All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. He's already agreed with you that that was not an accurate assessment and didn't represent his overall judgement, just a careless reiteration of what someone else said; and that was about 4000 posts ago! No, he has never admitted that. He has tried to explain it away - but never said his assessment was inaccurate. In fact, he has repeatedly argued the opposite. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
#70
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Dipoles, why height matters
On 11/23/2014 4:07 PM, wrote:
Jerry Stuckle wrote: ssnip All I said was your comment about an 80 meter dipole under 100' off the ground sucks is wrong. And I supplied the proof for it. You went into a multipost rage when it was implied that something you did was less than perfect and you are still raging about it. Your proof, troll? Oh, on the rage issue - you're projecting (again). -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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