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#1
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Anyone know where I can find plans for an artificial ground?
napisal w wiadomosci ... I'm probably known as the anti-ground.. lol.. IE: I don't believe in RF grounds in the shack unless the antenna is fed directly from the shack. Which is fairly rare for me, but I have done it on 160m a few times.. My way of thinking is that an RF ground should always be a part of the antenna itself, preferably away from the shack. IE: a dipole is a complete antenna, and requires no ground for proper operation at the antenna, or at the shack. You don't need an RF ground at all. Your dipole is not the dipole but the monopole with the one radial. In the case of a vertical, the RF ground should be under the antenna if a monopole. IE: ground radials under a ground mount, or elevated radials for a ground plane. Your dipole is a horizontal monopole with the one radial. The vertical monopole can have only one radial. More radials is necessary for a strong stations. Do you understand? The only difference between your monopole and your vertical antenna is the direction. Do you agree? S* With either one of these, no RF ground is required for the shack. Ditto for a half wave vertical, which is a complete antenna. The only worry with it, is feed line radiation, which is a bit different issue. It just needs to be decoupled for the best operation. But that is something to be considered with any antenna, including the dipoles. The only ground I use at the shack is the safety ground for line voltage gear.. All lightning grounding must be at the antenna/mast, and at the entrance to the shack. "ground window". I quit using a shack RF ground in the mid 90's or so.. Ain't missed it all at so far... I actually had more issues when running high power "KW+" with a shack RF ground vs not using one. The use of the ground wire tuning may well help it work better on certain bands to prevent a hot shack. But I consider it a band aid to help hide problems that actually should be addressed at the antenna. Or in a perfect world at least.. BTW, I do not agree with the notion that an antenna needs to be resonant. That is another wives tail, as pointed out by Cecil. Even a dipole that is .05 WL long will radiate nearly all power that is applied to it. And antennas are reciprocal between radiating, and receiving. The trick is getting the power to and from the small antenna without it turning into heat. :/ There can be problems with excess loss, but it's not the element's fault for being non resonant. |
#2
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Anyone know where I can find plans for an artificial ground?
On Friday, April 26, 2013 2:59:05 AM UTC-5, Szczepan Bialek wrote:
IE: a dipole is a complete antenna, and requires no ground for proper operation at the antenna, or at the shack. You don't need an RF ground at all. Your dipole is not the dipole but the monopole with the one radial. A monopole with one opposite radial is a dipole. :/ In the case of a vertical, the RF ground should be under the antenna if a monopole. IE: ground radials under a ground mount, or elevated radials for a ground plane. Your dipole is a horizontal monopole with the one radial. No, it's a dipole. The vertical monopole can have only one radial. I suspect that statement is going to be quite a shock to the hundreds of stations that lay out 120 or more of them. More radials is necessary for a strong stations. To equal a certain level of ground loss, over a given amount of ground conductivity, the number of radials required under a monopole will depend on it's height above ground in wavelength. Do you understand? Probably, when I'm under the clinical supervision of a doktor. :/ The only difference between your monopole and your vertical antenna is the direction. Do you agree? No, because you are mislabeling a dog, and trying to compare it to a cat. In free space, the only difference between a vertical dipole, and a horizontal dipole is direction. |
#3
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Anyone know where I can find plans for an artificial ground?
napisal w wiadomosci ... On Friday, April 26, 2013 2:59:05 AM UTC-5, Szczepan Bialek wrote: Your dipole is not the dipole but the monopole with the one radial. A monopole with one opposite radial is a dipole. :/ "A dipole is a symmetrical antenna, as it is composed of two symmetrical ungrounded elements. Therefore it works best when fed by a balanced transmission line, such as a ladder line." From: http://en.wikipedia.org/wiki/Dipole_antenna The only difference between your monopole and your vertical antenna is the direction. Do you agree? No, because you are mislabeling a dog, and trying to compare it to a cat. In free space, the only difference between a vertical dipole, and a horizontal dipole is direction. Dipole has "two symmetrical ungrounded elements". Your dipole has the one grounded: http://en.wikipedia.org/wiki/File:Di..._in_meters.png A Dog and a cat are animals. But quite different. The name "dipole" is like animals. The dipole with grounded one leg is quite different from the "symmetrical dipole". Do you agree? S* |
#4
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Anyone know where I can find plans for an artificial ground?
On Friday, April 26, 2013 10:52:18 AM UTC-5, Szczepan Bialek wrote:
The dipole with grounded one leg is quite different from the "symmetrical dipole". According to the official IEEE definition of a "dipole", it is any antenna with approximately the same radiation pattern as a dipole. -- 73, Cecil, w5dxp.com |
#5
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Anyone know where I can find plans for an artificial ground?
"W5DXP" napisal w wiadomosci ... On Friday, April 26, 2013 10:52:18 AM UTC-5, Szczepan Bialek wrote: The dipole with grounded one leg is quite different from the "symmetrical dipole". According to the official IEEE definition of a "dipole", it is any antenna with approximately the same radiation pattern as a dipole. Of course: "Dipoles have a radiation pattern, shaped like a toroid (doughnut) symmetrical about the axis of the dipole. The radiation is maximum at right angles to the dipole, dropping off to zero on the antenna's axis. The theoretical maximum gain of a Hertzian dipole is 10 log 1.5 or 1.76 dBi. The maximum theoretical gain of a ?/2-dipole is 10 log 1.64 or 2.15 dBi." The antenna like this: http://en.wikipedia.org/wiki/File:Di..._in_meters.png ". However, coax is not symmetrical and thus not a balanced feeder. It is unbalanced because the outer shield is connected to earth potential at the other end. When a balanced antenna such as a dipole is fed with an unbalanced feeder, common mode currents can cause the coax line to radiate in addition to the antenna itself,[5] and the radiation pattern may be asymmetrically distorted" Such antenna is MECHANICALY symmetrical. But electrically is rather like the Marconi monopole: http://en.wikipedia.org/wiki/File:A6-3EN.jpg Remember: The grounded leg is the radial. S* |
#6
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Anyone know where I can find plans for an artificial ground?
Szczepan Bialek wrote:
Remember: The grounded leg is the radial. You think that because one end of the coax has its shield grounded, the other end has its shield at ground potential. That is not true. At radio frequencies, there can be a potential at one end of a conductor even when the other end is grounded. It will result in a radiating outer conductor of the coax, but not in a grounded leg of the dipole. |
#7
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Anyone know where I can find plans for an artificial ground?
Szczepan Bialek wrote:
"W5DXP" napisal w wiadomosci ... On Friday, April 26, 2013 10:52:18 AM UTC-5, Szczepan Bialek wrote: The dipole with grounded one leg is quite different from the "symmetrical dipole". According to the official IEEE definition of a "dipole", it is any antenna with approximately the same radiation pattern as a dipole. Of course: "Dipoles have a radiation pattern, shaped like a toroid (doughnut) symmetrical about the axis of the dipole. The radiation is maximum at right angles to the dipole, dropping off to zero on the antenna's axis. The theoretical maximum gain of a Hertzian dipole is 10 log 1.5 or 1.76 dBi. The maximum theoretical gain of a ?/2-dipole is 10 log 1.64 or 2.15 dBi." True. The antenna like this: http://en.wikipedia.org/wiki/File:Di..._in_meters.png ". However, coax is not symmetrical and thus not a balanced feeder. It is unbalanced because the outer shield is connected to earth potential at the other end. When a balanced antenna such as a dipole is fed with an unbalanced feeder, common mode currents can cause the coax line to radiate in addition to the antenna itself,[5] and the radiation pattern may be asymmetrically distorted" True to a point. The outer shield may or may not be connected to earth potenial anywhere. Such antenna is MECHANICALY symmetrical. But electrically is rather like the Marconi monopole: http://en.wikipedia.org/wiki/File:A6-3EN.jpg Confused babble. The antenna is the antenna and the feedline is the feedline. Whether or not the feedline radiates is totally irrelevant to what the antenna does. This is something you are totally incapable of understanding. Remember: The grounded leg is the radial. Remeber: This is puerile, ignorant, nonsense. -- Jim Pennino |
#8
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Anyone know where I can find plans for an artificial ground?
Szczepan Bialek wrote:
Dipole has "two symmetrical ungrounded elements". Yep. Your dipole has the one grounded: Nope. http://en.wikipedia.org/wiki/File:Di..._in_meters.png No ground here idiot. A Dog and a cat are animals. But quite different. The name "dipole" is like animals. The dipole with grounded one leg is quite different from the "symmetrical dipole". Do you agree? S* I agree everything you just said is ignorant gibberish. -- Jim Pennino |
#9
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Anyone know where I can find plans for an artificial ground?
On Friday, April 26, 2013 10:20:00 AM UTC-5, wrote:
In free space, the only difference between a vertical dipole, and a horizontal dipole is direction. So --- which way is up? -- 73, Cecil, w5dxp.com |
#10
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Anyone know where I can find plans for an artificial ground?
On Friday, April 26, 2013 11:21:35 AM UTC-5, W5DXP wrote:
On Friday, April 26, 2013 10:20:00 AM UTC-5, wrote: In free space, the only difference between a vertical dipole, and a horizontal dipole is direction. So --- which way is up? Good question.. |
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