| Author |
Message |
    
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 300
Registered: 6-2003
| | Posted on Sunday, November 28, 2004 - 5:52 pm: | 
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I think I've figured out why my dipole works so extra good in a certain location. My dipole is almost vertical (sloped) over the concrete drive. We have a circle drive. I suppose there is mesh wire in that concrete creating a super groundplane. What do you guys think?
mikefromms |
Tech808
Moderator
Username: Tech808
Post Number: 4175
Registered: 8-2002
| | Posted on Sunday, November 28, 2004 - 6:52 pm: |
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Mikefromms,
This would be a good Question for Tech833 in the Ask the Tech Area under Antennas.
With so many different posts and topics in the OPEN area here he might not see it.
Lon
Tech808
CEF808
N9OSN |
Racer X (Unregistered Guest)
Unregistered guest
| | Posted on Sunday, November 28, 2004 - 11:13 pm: |
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Concrete itself acts as an "Ufer" ground. The wire mesh doesn't hurt, but the high mineral content and the tendency of concrete to hold moisture make it a good ground plane. |
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 301
Registered: 6-2003
| | Posted on Sunday, November 28, 2004 - 11:28 pm: |
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This may explain a lot. ummm...the thing is pretty omin-directional yet somewhat at a slant. The performance is astonishing to me and those who hear this antenna. As one man put, I don't see how you could improve on it.
mikefromms |
Tech808
Moderator
Username: Tech808
Post Number: 4184
Registered: 8-2002
| | Posted on Monday, November 29, 2004 - 6:35 pm: |
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Mikefromms,
I asked Tech833 about running my Push-up pole threw the roof and mouniting it to the Concrete floor in our garage and then drilling and running a Ground rod threw it and he Said NO as the Ground under the Concrete dries out and then there is no good ground there after the concrete has been there for awhile.
Not sure about a di-pole but you might want to make a post where he will see it and then you will have the answer.
As antennas are his profession and daily job and field of experience I am quite shure you will get a good answer to your question.
Lon
Tech808
CEF808
N9OSN |
Highlander
Advanced Member
Username: Highlander
Post Number: 701
Registered: 12-2001
| | Posted on Monday, November 29, 2004 - 8:50 pm: |
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My understanding of dipoles is that they do not have or need a groundplane. They are a balanced antenna.
Your dipole is working well because you got it right when you built and installed and tuned it. You might consider getting and using a 1:1 balun to reduce the possibility of feedline radiation and/or a slightly distorted pattern due to feeding it with an unbalanced feedline (coax), but I've used them without the balun with no significant problems. |
Racer X (Unregistered Guest)
Unregistered guest
| | Posted on Tuesday, November 30, 2004 - 5:09 am: |
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If you want to learn about Ufer grounds throw the terms ufer and ground into google (the only worthwhile search engine on the interent that's free) and read all about it.
Here's a link to an article that appeared in Radio World a few years ago:
http://www.scott-inc.com/html/ufer.htm
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Tech833
Moderator
Username: Tech833
Post Number: 897
Registered: 8-2002
| | Posted on Tuesday, November 30, 2004 - 10:02 am: |
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I found this thread but already answered in the other thread. |
Mikefromms
Intermediate Member
Username: Mikefromms
Post Number: 304
Registered: 6-2003
| | Posted on Tuesday, November 30, 2004 - 5:23 pm: |
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Thx for the reply.
mikefromms |
