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Groundplane, or something else?
What characteristics would a 1/2 wave dipole have if one side was near vertical, and the other side buried along the ground? Would it act like a poorly counterpoised groundplane vertical, or something else? Any redeeming qualities? Ed |
You guessed it...It's a vertical with one radial...
Qualities? Hummmm....It's a subpar dipole... Hummmm....it's a subpar vertical too...:/ Any redeeming qualities would have to be in the eye of the beholder..MK |
You guessed it...It's a vertical with one radial... Qualities? Hummmm....It's a subpar dipole... Hummmm....it's a subpar vertical too...:/ Any redeeming qualities would have to be in the eye of the beholder..MK In what manner would this vertical be "subpar? "If one were looking for for a vertical with more radiation in one direction, would this be something to consider? Ed |
On Sun, 30 Jan 2005 06:01:26 GMT, Ed
wrote: What characteristics would a 1/2 wave dipole have if one side was near vertical, and the other side buried along the ground? Would it act like a poorly counterpoised groundplane vertical, or something else? Any redeeming qualities? Ed It would fit on your real estate. If you add three radials you would have a good ground plane. I have had in the past the Taylor Radio 4 band vertical and the Hustler 5 band vertical. I ran both of them with only a 6 foot ground rod in the ground with no radials. They worked. I doubt that they worked as well as my dipoles at 65 feet or so, but they did work. Why do you want the antenna? That may determine how good it is. If you want a 'money is no object super duper DX antenna', then it won't be worth the time of day. But if you need an antenna to fit precisely where that antenna is so you can occasionally rag chew and not spend any more money for an antenna, it will be perfect. -- Buck N4PGW |
Ed wrote:
What characteristics would a 1/2 wave dipole have if one side was near vertical, and the other side buried along the ground? Would it act like a poorly counterpoised groundplane vertical, or something else? Any redeeming qualities? When two radials are 180 degrees apart and elevated, they tend to cancel the radiation from each other. When you bury one radial, you ensure that ~half your RF energy is lost. If you bury that one radial vertically, you do indeed lose half your signal since you have put half of your dipole underground. Ground mounted verticals give up approximately half their power to ground losses. Then they give up approximately another 3 dB to a rotatable dipole. Approximately 10 ohms of the feedpoint impedance for mobile antennas is ground losses. (Please note that everything I said is approximate. :-) -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
Compared to a vertical with more ground radials, I believe you'd have
less radiation in other directions rather than more in the desired direction. Roy Lewallen, W7EL Ed wrote: In what manner would this vertical be "subpar? "If one were looking for for a vertical with more radiation in one direction, would this be something to consider? Ed |
It would be subpar because of excess ground losses #1. You only have
one radial, and the antenna is low to the ground. As far as radiation in one direction, I agree with Roy. It would probably be about the same in that direction as another "poorly grounded" antenna, except that in the other directions, it would be even worse. I think in the real world, you will find it to be hardly directive at all. Or at least enough to be useful anyway...To be really directive, a vertical system needs multi elements. IE: phased verticals, bobtail curtains, etc...A bobtail curtain is a mean antenna on 40m at night. Only the curtains, and the few lucky dogs running yagi's could beat my elevated ground plane to VK land late at night. A friend of mine across town ran a bobtail curtain. He could dog my GP most every night. But he's got three elements compared to my one... MK |
wrote:
It would be subpar because of excess ground losses #1. You only have one radial, and the antenna is low to the ground. As far as radiation in one direction, I agree with Roy. It would probably be about the same in that direction as another "poorly grounded" antenna, except that in the other directions, it would be even worse. EZNEC agrees. With four radials one foot above ground the gain is -0.53 dBi. With one radial one foot above ground the gain is -1.62 dBi in the direction of the one radial and - 6 dBi in the opposite direction. -- 73, Cecil http://www.qsl.net/w5dxp ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
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On Sun, 30 Jan 2005 22:56:55 -0600, Cecil Moore
wrote: wrote: It would be subpar because of excess ground losses #1. You only have one radial, and the antenna is low to the ground. As far as radiation in one direction, I agree with Roy. It would probably be about the same in that direction as another "poorly grounded" antenna, except that in the other directions, it would be even worse. EZNEC agrees. With four radials one foot above ground the gain is -0.53 dBi. With one radial one foot above ground the gain is -1.62 dBi in the direction of the one radial and - 6 dBi in the opposite direction. How does it rate it with that one radial buried in the ground as in the OP rather than above the ground? -- 73 for now Buck N4PGW |
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