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Re: www.vlf.it update

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  • Walter
    Hi, I don t talk about the geometry of the lines up in the air. Your photo shows a 3 phase supply system. We need to look at the voltages only: in a 220 kV
    Message 1 of 71 , Jun 25, 2012
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      Hi,

      I don't talk about the geometry of the lines up in the air.

      Your photo shows a 3 phase supply system.
      We need to look at the voltages only: in a 220 kV system we have

      pahse A : u(t) = sqrt(2)*220000 * sin ( 2* pi*50 *t )
      pahse B : u(t) = sqrt(2)*220000 * sin ( 2* pi*50 *t + 120 degrees)
      pahse C : u(t) = sqrt(2)*220000 * sin ( 2* pi*50 *t + 240 degrees)

      These phase offsets do have a prominent influence on the far field E vector.(a distance large in comparison to the distance between the lines - this is where geometry really counts)
      Likewise for the current under your assumption of purely resistive load.

      I think you do it right only the text was misleading to me.

      Walter
    • reromeroit
      A new article is on line: A High Bandwidth, Low Noise Optical VLF Link This article describes the design, characteristics and use of a high bandwidth, low
      Message 71 of 71 , Feb 2
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        A new article is on line:
        "A High Bandwidth, Low Noise Optical VLF Link"

        This article describes the design, characteristics and use of a high bandwidth, low noise optical system for connecting a VLF receiver to a data sampling system. This easy to build, inexpensive system has a flat response to over 200KHz, and a noise curve well below the VLF band.

        by Mike Smith


        73, Renato Romero
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