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## [TowerTalk] Beam alignment

 To: [TowerTalk] Beam alignment alsopb@vance.net (alsopb@vance.net) Thu, 3 Jul 1997 13:39:00 -0500
 ```Guys, You people wishing to split a gnat's eyelash with beam/rotor alignment ought to also consider the following: 1) Where is your beam pattern really with respect to the physicial antenna? I've seen cases where imbalances in the design and feeding have squinted patterns 15 degrees or more from where you'd expect it to be. Actually measure your pattern sometime with a local and find out. You may be surprised. You people with triband quads and a single feedline may discover that your 10 meter pattern has two lobes about 45 degrees either side of the "true" peak with a depression at the position of the "true" peak. 2) The popular Ham IV rotor has break stopping points only every 4.8 degress. Couple a slight misalignement with this and you could easily be off almost 10 degrees from where you wanted to point it. 3) Signals don't always come from the great circle direction. If you don't believe it, try aiming your 40 meter beam to Japan via great circle in the morning. Then aim it further at the equator and compare the signal strenghts. K3KO's Theorem; The strongest signal always comes from the strongest signal direction. 4) If you have a globe, you can determine an accurate enough true north/magnetic north variation by sticking a pin in Great Bear Lake in VE8(an approximate location of the magnetic north pole, if memory serves. Correct me if you have a better geographical fix), the north pole and your QTH. Run a string from your QTH to the true north pole, another string from your QTH to the VE8 pin and measiure the angle between the two. That's it. There is no magic involved. Oh, by the way, the position of the magnetic North pole is constantly moving. Enough so that the airports have to sometimes repaint the numbers of their runways to keep up.. Bottom line, be practical. The real world isn't neat and clean. Don't waste your time and energies on things that are really not important. Not everything is known with absolute precision or ever will be. Mother nature is full of suprises. Let's see, true north is 6.523 degrees East of magnetic north from here, that means I have to .... de Brian/K3KO Vance Net Inc End Of Message -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com Administrative requests: towertalk-REQUEST@contesting.com Problems: owner-towertalk@contesting.com Search: http://www.contesting.com/km9p/search.htm ```
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