Guglielmo Marconi´s antenna design

The article reviews the antenna design used for the earliest experiments employing untuned systems, culminating in the December, 1901 transatlantic experiment from Poldhu, UK to St Johns, Newfoundland. To understand the system it is necessary to consider the method by which signals were detected. The filings coherer was a device on which Marconi (1967) himself was probably the leading practical expert. This uses an evacuated glass tube partially filled with filings (the material was actually various combinations of nickel and silver), and containing two electrodes immersed in the filings. To compare the performance of various possible antennas we have considered four possibilities which are: a monopole, a Tee antenna (i.e. a monopole with a horizontal top-loading wire), a fan antenna and a cone antenna. All were 43 m high, and the last three had a horizontal extent of 45 m. Any supporting structures were not included in the simulation