There are two distinct and different issues here. Take a look at how the ARRL Antenna Book tackles them quite separately. 1. Antenna efficiency: directly affected by the ground conductivity in the Re
The ARRL Antenna Book puts it much more succinctly than I just did - Page 3-20 of 21st Edition: "In short, far-field losses for vertically polarized antennas are highly dependent on the conductivity
James, I don't know who Mr. Gordo is, but those comments directly contradict the ARRL Antenna Book and the evidence from EZNEC. I've posted the EZNEC elevation patterns here: http://www.karinya.net/g
That sounds like my XYL - she's also right even when she's wrong! 73, Steve G3TXQ _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com
I guess "Gordo" never read any of the Antenna Engineering textbooks! The Handbook of Antenna Design Vol 2, Alan Rudge: "The radial ground system and the ground surrounding it, within a radial distanc
ARRL Extra Class License Manual, Page 9-8 Effects of Ground and Ground Systems: "There is little you can do to improve the far-field, low-angle radiation pattern of a vertically polarized antenna if
The most directly relevant question is E9C15: What strongly affects the shape of the far-field, low-angle elevation pattern of a vertically polarized antenna? A. The conductivity and dielectric const
Stuart, That seems a very "generous" interpretation of what Gordo is quoted as saying: "What strongly affects the shape of the far-field low angle which we want? the low angle elevation pattern of a
Folk who have been following the discussion may be interested in this chart: http://www.karinya.net/g3txq/temp/ground_zones_2.png It shows how the optimum take-off angle of an 80m quarter-wave vertic
Walt, Exactly right! Of course, if those 120 radials extended several wavelengths from the antenna, well into into the Fresnel Zone, they might begin to have some effect on the elevation angle. But b
Rick, I'm right in the middle - about 100 miles from the sea in any direction. For that to work I guess I'm going to have to try the ELF bands ;) 73, Steve G3TXQ _____________________________________
Jerry, That's interesting! Similar response on half a dozen other issues, either within QST articles or the Antenna Book; I've now given up trying :) 73, Steve G3TXQ _________________________________
Jerry, Please don't think I'm trying to be contentious, but your comment challenged my established view of what "dBi" represents. That led me on a literature search starting with my (very old) Master
Jerry, A picture paints a thousand words: http://www.karinya.net/g3txq/temp/ladderline_zo.png 73, Steve G3TXQ _______________________________________________ TenTec mailing list TenTec@contesting.com
Jerry, Then we'll probably have to agree to disagree :) 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
Jerry, I think I had one of the curve "smoothing" options invoked on the spreadsheet graphing - that may account for it! 73, Steve G3TXQ _______________________________________________ TenTec mailing
Jerry, I can understand that the interpretation of dBi which appears in most engineering texts (and possibly the IEEE definition?) throws up conundrums with which you are uncomfortable. But what I th
Ray, If that had happened to me, I would have had little respect for professors who can't resolve such a simple issue! Steve G3TXQ _______________________________________________ TenTec mailing list
Correct! I believe it was Jerry who pointed me to the accurate formula a couple of years ago on this very List. I was considering how to build low impedance balanced line with a Zo in the range 50 Oh
Paul, I tried an 80m vertical dipole with its tip just 1ft above ground. Of course the TO angles are generally lower than the quarter-wave because of the increased vertical dimension. The results pre