. QST . enna height. 1 he fieldintensity is expressed in millivolts per meter at a dis-tance of one mile for one kilowatt input. Perfectly con-ducting ground and zero loss resistance are multiband antennas because their angle of radia-tion increases with frequency. This is true exceptfor the region where the vertical antenna is lessthan wavelength long. Between wavelength long the radiation angle de-creases as frequency increases. This is shown inFig. 1, which is a field-intensity plot in thevertical plane of a vertical antenna for threedifferent frequenci
. QST . enna height. 1 he fieldintensity is expressed in millivolts per meter at a dis-tance of one mile for one kilowatt input. Perfectly con-ducting ground and zero loss resistance are multiband antennas because their angle of radia-tion increases with frequency. This is true exceptfor the region where the vertical antenna is lessthan wavelength long. Between wavelength long the radiation angle de-creases as frequency increases. This is shown inFig. 1, which is a field-intensity plot in thevertical plane of a vertical antenna for threedifferent frequencies. These curves assume zeroloss resistance in the antenna and a perfectlyconducting ground plane. The actual value ofresistive loss in the antenna will merely shrink *319 Summit St., Granville, Ohio. 1 The ARRL Antenna Book, page 186, 5th edition. 2 J. D. Kraus, Antennas, page 317; McGraw Hill Book Co. Edward C. Jordan, Electromagnetic Waves and Radiating Systetns, pages 482 and 483; Prentice-Hall, .IS .25 .35 .45 .55 .65 ANTENNA LENGTH IN WAVELENGTHS Fig. 2 — Input resistance is. length in wavelengthsfor vertical antennas of three dififerent length-to-diame-ter ratios. From Jordan. the curves slighth but not distort them. A lossyground plane such as earth will affect the curvesat extremely low elevation angles, which willshorten distances for ground-wave propagation,
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
