AM BROADCAST ANTENNAS WITH ELEVATED RADIALS - VARYING THE NUMBER OF RADIALS AND THEIR HEIGHT ABOVE GROUND

Previous computer-modeling studies indicated that four elevated radial s may be used in conjunction with an elevated vertical monopole (tower ) to produce radiated field strength which is equivalent to that emitt ed by a similar monopole using 120 buried radials. [1] Inquiries have been received concerning the effect of increasing the number of elevat ed radials, and/or changing the height of the radials above ground. An alysis shows that there seems to be an optimum number of elevated radi als for each height and soil type. Surprisingly, the continued additio n of more and more elevated radials eventually produces a reduction in performance. The computer code used for this work was NEC, a ''Method of Moments'' program developed at Lawrence Livermore National Laborat ory. [2]