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ANTENTOP- 03- 2003, # 004

The Underwater Communication System



To differentiate Tesla's wireless method from contemporary understanding of the technique, and from the misunderstandings arising from the chronology of Tesla's research into the nature of electrical communication, his method can be contrasted with modern patents for electrostatic submarine communication and the inventor's earlier work in this field. 


Contemporary Patents


L. Gilstrap's patent for an Electrostatic Communication System, #3,964,051, issued June 15, 1976, describes a device consisting of two concentric conducting spheres (#26 & #28) separated by a dielectric layer to form a monopole radiator for electrostatic waves.


Gilstrap patent 3,964,051


Curry states:


 The antenna system for an electromagnetic emission into space circulates energy in accordance with the laws governing electrical current in motion.  Since the field strength pro­duced by an antenna is propor­tional to the alternating currents circulating in it, its optimum struc­tural relationships are directed to a reduction of the total antenna resis­tance, thus to increase the total cur­rent for a given power input to a radiator.13


   He adds:


Being a current-actuated device, such an [electromagnetic] antenna will not operate in any physical conducting medium such as


water or earth.14

The patent states that "longitu­dinal electrostatic or capacitive waves, also called scalar or polarization waves because of their relationship to the Maxwell wave equa­tions" are the means of propagation but the patent does not explain how these waves differ from conventional forms of electromagnetic radiation.  It simply states that as the spheres are subject to voltages of opposite polarity the "outer sphere then appears as an ideal mono­pole radiator to the external dielectric medi­um, in this case water."12


In this configuration, electric field is confined to the region between the two conducting spheres of the transmitter. Little energy, if any, is available to stress the external dielectric medium, the water.


P. Curry's patent for an Underwater Electric Field Communica-tion System, #3,265,972, issued August 9, 1966 proposes a ra-diator of a different configuration and presents a detailed discus-sion of communication by electrostatic induction.




While a radiator for electromagnetic emission produces its field strength by the effect of changing currents; the radiator for electrostatic emission of the type here to be described produces its field strength by the effect of changing potentials.15



   Curry proposes "the electrical potentials of the signal to be transmitted to two equal metal plates (#17 & #18) each of which is hermetically sealed within insulating material (#20 & #21) … immersed in a conducting fluid such as sea water."16 By applying a varying potential to the plates of the radiator, charge of opposite polarity accumulates on the two plates such that a charge gradient exists in the region between the radiators. The patent explains:

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