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TRANSMITTING ANTENNA SYSTEM FOR AUDIO INDUCTION COMMUNICATION SYSTEM

  • US 3,598,923 A
  • Filed: 04/21/1969
  • Issued: 08/10/1971
  • Est. Priority Date: 04/21/1969
  • Status: Expired due to Term
First Claim
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1. An antenna system for use with an audio induction communication system having a signal source for delivering an electrical signal which varies in frequency directly with the frequency of the message to be transmitted and for producing an active message field in a three dimensional pickup zone located in front of an exhibit and which zone extends horizontally along said exhibit, a substantial distance perpendicularly away from said said exhibit and vertically between two limits sufficient to include the levels of receivers as normally worn or carried by persons viewing said exhibit, said antenna system comprising a plurality of antennas each consisting of an elongated magnetic core and a winding on said core, said antennas being spaced from one another along the length of said exhibit and behind said zone so that each produces a magnetic field a portion of which extends forwardly therefrom and passes through said zone and which portion at any given instant has only one generally vertical direction, and means connecting said antennas to said signal source with such a polar relationship to one another that within said zone said fields are in generally aiding relation to each other.

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