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Richard Fry wrote:
_______ I'm not considering that the ground wave signal _provides_ any of that low-angle DX coverage. It is the direct radiation existing in the radiation pattern of the monopole at low elevation angles that can do so. No ground reflection is necessary to create that field - it is launched by the monopole itself. Below is a link to a clip from Terman's Radio Engineers Handbook, 1st edition, showing that the greatest single-hop range for skywave signals occurs from the radiation of the monopole at elevation angles of less than ten degrees. But looking at a NEC far-field analysis this would seem impossible, due to the greatly reduced fields in this sector that NEC shows for a vertical monopole over real earth. This clip was done for MW frequencies, but the concept would apply equally at HF, would it not? http://i62.photobucket.com/albums/h8...ermanFig55.jpg RF I for one, think you correct. What is "launched" at the antenna obeys physics laws at 100 ft., 1000 ft., 10,000 ft., 100,000 ft., 1,000,000 ft. ... the signal does not ever suffer magical, mystical, supernatural manipulations--EVER! Regards, JS |
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