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Can take-off angle be too low?
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by ES5TV on June 28, 2000
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How important is it to have the ability of running very low elevation angles in upper HF contesting? How much does it add to the score if one can run 10 meters with beams higher than 200 feet and get the take-off angle down to 2-3 degrees? N6BV statistics actually indicate the high theoretical QSO precentage at 1-3 degrees.
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RE: Can take-off angle be too low?
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by W4ZV on June 29, 2000
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Yes, take-off angle can definitely be too low! You would never want to have only a single 10 meter antenna at
200 feet because most of time propagation paths are at much higher angles than 1-3 degrees. From here to EU, N6BV statistics show the lowest angle for any propagation is 3 degrees and to Japan it is 1 degree. However, most of the paths are at higher angles, especially while we are at the solar maximum. For example, to EU the range is 3-10 degrees with peaks being at 5 and 7 degrees...to Japan, the range is 1-9 degrees with peaks at 1 and 7 degrees.
Over flat terrain, monobanders at 35/70/105/140ft have take-off angles peaking at 13/7/5/3 degrees on 10 meters. If I had to choose one height for 10 meters at my QTH, it would probably be at 70ft. This is not to say an antennna at 200ft would not be useless! It would certainly be nice for certain openings (long path, backscatter, etc)...it just would not be better than one at 70ft most of the time.
73, Bill W4ZV
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