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## Re: [TowerTalk] trees and verticals

 To: towertalk@contesting.com Re: [TowerTalk] trees and verticals Jim Brown jim@audiosystemsgroup.com Tue, 27 Dec 2011 09:32:56 -0800 mailto:towertalk@contesting.com>
 ```On 12/27/2011 8:04 AM, Eddy Swynar wrote: > And in 25 words, or less, explain why." My last paragraph attempted to do that. But antennas and radio are far to complex to describe their behavior in 25 words or less. One must struggle to get one's mind around the laws of physics. We can do relatively simple math to describe the behaviour of a simple antenna in free space, or over an ideal earth with nothing in the way, and the patterns are pretty and fairly easy to understand. Trees, rain gutters, buildings, wiring in those buildings, towers, feedlines to other antennas, even losses in the earth itself that vary from one spot to another, are all complications that are incredibly difficult to model mathematically. What I have attempted, and what Doug and Roger chimed in to contribute to, are some careful observations of how antennas we have built have worked around one set of these complications -- trees. To Doug -- my 160M Tee vertical that works well is more or less in the middle of the clearing around my house and shack, which we here in the California mountains have learned is critical for survival in a wild fire. The top of the Tee is suspended from a redwood on one end and big Madrone on the other. I have a 170 ft loaded horizontal dipole for 160M at 110 ft in that clearing, and when I first had both it and the Tee vertical, I spent a lot of time switching between the two antennas in contests. What I learned in that first year of very actively comparing them was that on any given path, at any given time, one might be better than the other, and it was difficult to predict which would be better. BUT -- in the daylight hours (160M contests start at 2PM out here), the vertical was ALWAYS at least 10dB better. I found that I could consistently work everything I could hear out to about 1,000 miles (Seattle, Denver, New Mexico, AZ) before dark, and for a few hours after dark, with the vertical, whereas I wouldn't even get "QRZ?" with the horizontal dipole for those distant stations. And that's a horizontal dipole at 110 ft! And Eddy -- I've heard you a few times during contests in the morning hours, but you don't hear me calling (even though I work a lot of east coast stations). 73, Jim K9YC _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread Re: [TowerTalk] trees and verticals, (continued) Re: [TowerTalk] trees and verticals, Jamie WW3S Re: [TowerTalk] trees and verticals, David Gilbert Re: [TowerTalk] trees and verticals, Eddy Swynar Re: [TowerTalk] trees and verticals, N6FD Re: [TowerTalk] trees and verticals, David Gilbert Re: [TowerTalk] trees and verticals, Stan Labinsky Jr. Re: [TowerTalk] trees and verticals, Rik van Riel Re: [TowerTalk] trees and verticals, Jim Lux Re: [TowerTalk] trees and verticals, David Gilbert Re: [TowerTalk] trees and verticals, K8RI Re: [TowerTalk] trees and verticals, Jim Brown <= Re: [TowerTalk] trees and verticals, kr2q Re: [TowerTalk] trees and verticals, David Thompson Re: [TowerTalk] trees and verticals, john Re: [TowerTalk] trees and verticals, K8RI Re: [TowerTalk] trees and verticals, Jim Chaggaris Re: [TowerTalk] trees and verticals, Roger Parsons Re: [TowerTalk] trees and verticals, Frank Re: [TowerTalk] trees and verticals, David Gilbert Re: [TowerTalk] trees and verticals, Jim Lux Re: [TowerTalk] trees and verticals, David Gilbert