[Antennas] Ground Planes

[Ron W7MRR]

One might also consider the effects of burying all that copper under the sod.  You might end up with alot of dead grass . . . 

Ron W7MRR



 --- On Tue 04/05, Dr. William J. Schmidt, II < bill at wjschmidt.com > wrote:
From: Dr. William J. Schmidt, II [mailto: bill at wjschmidt.com]
To: antennas at mailman.qth.net
Date: Tue, 5 Apr 2005 21:45:04 -0500
Subject: Re: [Antennas] Ground Planes

One would think this would be the ultimate approach... but....  I have made <br>a study of radial installations, and the law of diminishing returns comes <br>into play very fast as the coverage of the radial dimension increases. <br>Notable pioneers in broadcasting of the mid- 1930's pretty much got it right <br>in their experiments... for recap, see the July 2000 QST article by Rudy <br>Severens on "verticals, grounding systems and some history".  What you find <br>is that once you get past a specific radial coverage/ density, the marginal <br>improvement per radial (read that coverage) is very very small... and in <br>some cases immeasurable.<br><br>In my case, I installed a mil. Shakespeare 222 in my antenna-challenged <br>community as a stealth device.  I designed a radial burying device for my <br>medium sized tractor (which I now sell commercially) to bury radials.  As I <br>began burying radials, I made measurements on the resulting system (they are <br>quarter wave for 80 meters)... impedance measurements on the antenna on <br>80-10 meters, and distant/ elevation field strength measurements.  I reached <br>the limits of my test equipment when I hit 240 radials... and basis my <br>threshold, about 120 radials was really optimum given the cost of the wire.<br><br>Meshing your back yard...  while it may give you wood... isn't really cost <br>practical.<br><br>Sincerely,<br><br>Dr. William J. Schmidt, II  K9HZ<br>Trustee of the North American QRO - Central Division Club - K9ZC<br><br>Email: bill at wjschmidt.com<br>WebPage: www.wjschmidt.com<br><br>"If computers get too powerful, we can organize them into a committee; that <br>will do them in."  -- Bradley's Bromide<br><br><br>----- Original Message ----- <br>From: "Mel Vance" <icra at galaxynet.com><br>To: <antennas at mailman.qth.net><br>Sent: Tuesday, April 05, 2005 4:53 PM<br>Subject: Re: [Antennas] Ground Planes<br><br><br>>> Let me set up the parameters.  I have a back yard some 50-75 ft by<br>>> 50-75ft.  I am going to have it resodded.  I want to go to Lowes or<br>>> Home Depot and buy copper screening. , Roll it out and solder each<br>>> section together.  After the screening is in place, it will be covered<br>>> by sod.  It I put a mast in the center and bond it to the screen and<br>>> place an all band vertical on the mast, will this satisfy the ground<br>>> plane requirements of a vertical.   This would be great to anyone<br>>> building a new home and in need of an excellent ground plane for a<br>>> vertical.  Any comments would be appreciated and should help others on<br>>> the reflector.<br>>><br>> Boy...thought I was the only one who had thought of this........<br>><br>> Well....part of this will depend on how much you have to spend.........<br>><br>> If the funds are available, I would put 2 or 3 layers, over-lapping the <br>> seams, and solder it all<br>> together well. This will make it last longer than just a single layer.<br>><br>> I would also use some copper stakes about every foot and solder to the <br>> screen. Just a foot<br>> long would do it. These will help bond it all to your soil (electrically), <br>> and help keep it from<br>> working to the surface due to freezing and thawing. You still may need to <br>> add soil from time<br>> to time due to settling or erosion.<br>><br>> An idea I had was to add 1/4" copper pipe with very small holes drilled <br>> used to dribble water<br>> through the ground mat area.....more erosion potential, but better soil <br>> conductivity...I hope.<br>> Could catch rain from your down spouts in a barrel to feed the system.<br>><br>> Just my thoughts..........<br>><br>> Mel<br>> N7OKL<br>><br>> ______________________________________________________________<br>> Antennas mailing list<br>> Home: http://mailman.qth.net/mailman/listinfo/antennas<br>> Help: http://mailman.qth.net/mmfaq.html<br>> Post: mailto:Antennas at mailman.qth.net<br>> <br><br><br>______________________________________________________________<br>Antennas mailing list<br>Home: http://mailman.qth.net/mailman/listinfo/antennas<br>Help: http://mailman.qth.net
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