Download or read book Preliminary Tests of a Center-fed 8000-foot Vertical Half-wave Transmitting Dipole written by E. A. Lewis and published by . This book was released on 1969 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was demonstrated experimentally that an 8000-foot half-wave antenna-wire, suspended vertically from a helicopter and driven at its center by a battery-powered transmitter, provides an efficient radiating system for frequencies around 60 kHz. In-flight antenna impedance measurements were made in two different ways using telemetry techniques. Supporting information was obtained from a 4000-foot open wire transmission line erected on poles, and from laboratory bridge measurements on short samples of wire. Certain mechanical properties of the wire and the method used for launching the antenna are described. The electric field strengths received on the ground, radiation patterns, radiation efficiency, bandwidth, scattered waves, and atmospheric-electric currents in the antenna, are discussed in detail. (Author).