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## Re: [TenTec] NEC, ground, grounds, and radials.

 To: tentec@contesting.com Re: [TenTec] NEC, ground, grounds, and radials. "Dr. Gerald N. Johnson" geraldj@weather.net, Discussion of Ten-Tec Equipment Fri, 07 Jan 2011 18:20:59 -0600 mailto:tentec@contesting.com>
 ```My conundrum is that I expect equal power intensity at the the measuring point from the isotropic source whether a ground plane is involved or not and that I also expect equal intensity from a vertical dipole in free space and a quarter wave vertical on the ground plane (except for the ground absorption at the real ground plane). To add to my confusion? if I take an infinitesimal vertical radiator an infinitesimal distance above the origin, such as a radiator of wire 0.00001 ft diameter spanning from 0.0001 to 0.0002 feet elevation with one segment at 1 MHz with ground plane I see a gain of -57 and a fraction dBi and in free space a gain of -60 dBi and the same fraction. Then if I make that an isotropic source by adding two more wires of the same length at the height of the middle of that first wire, one parallel to the X axis and one parallel to the Y axis and spaced one wire length from the middle of the vertical wire, I get -100 dBi gain over the half sphere over a ground plane or -100 dBi gain in free space. Each wire has a source in it. 73, Jerry, K0CQ On 1/7/2011 5:07 PM, Steve Hunt wrote: > Jerry, > > Then we'll probably have to agree to disagree :) > > On 07/01/2011 22:53, Dr. Gerald N. Johnson wrote: >> I fear its not a commonly held view though I'd think in broadcast >> circles NEC would be held in contempt because it seems by my analysis to >> predict twice the field power than would be measured in the real world. > > Not so! > > If you calculated the power density you would expect to see at that > range from an isotropic radiator in Free Space - one which radiates > uniformly in all directions - then apply the predicted EZNEC dBi figure, > it should match the power density you measured. > > As I see it, it's not a problem with EZNEC, it's how you define the > reference power density; and your definition seems to be out of step > with all the engineering references I can find. > > 73, > Steve G3TXQ > > _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec ```
 Current Thread Re: [TenTec] New and Improved Terminology, (continued) Re: [TenTec] New and Improved Terminology, Steve Hunt Re: [TenTec] New and Improved Terminology, Paul Christensen Re: [TenTec] New and Improved Terminology, Steve Hunt Re: [TenTec] New and Improved Terminology (NVIS origins), Rick - NJ0IP / DJ0IP Re: [TenTec] New and Improved Terminology (NVIS origins), Rick - NJ0IP / DJ0IP Re: [TenTec] New and Improved Terminology (NVIS origins), Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials., Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials., Steve Hunt Re: [TenTec] NEC, ground, grounds, and radials., Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials., Steve Hunt Re: [TenTec] NEC, ground, grounds, and radials., Dr. Gerald N. Johnson <= Re: [TenTec] NEC, ground, grounds, and radials., Steve Hunt Re: [TenTec] NEC, ground, grounds, and radials., Dr. Gerald N. Johnson Re: [TenTec] NEC, ground, grounds, and radials., Steve Hunt Re: [TenTec] New and Improved Terminology (NVIS origins), John Graves Re: [TenTec] New and Improved Terminology (NVIS origins), d . e . warnick Re: [TenTec] New and Improved Terminology (NVIS origins), John Graves Re: [TenTec] New and Improved Terminology (NVIS origins), Rick - NJ0IP / DJ0IP Re: [TenTec] New and Improved Terminology (NVIS origins), Rsoifer