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Modulation index

  1. Jan 1, 2012 #1
    ive been trying to proof the modulation index for Am transmission, it goes like this

    Vmax = a(1+u)
    Vmin = a(1-u)

    it basicilly describes the amount of infromation in the total power transmitted and should allways be between 0 & 1

    eventually the answer should come out to be

    u = (Vmax-Vmin)/(Vmax+Vmin)

    its the maths in between that is anoying the hell out of me, if any body has any info on doing this please help, ive tried matrices so dont bother !! :bugeye:

    thanks in advance.
  2. jcsd
  3. Jan 4, 2012 #2
  4. Jan 4, 2012 #3
    worse than useless response

    it does not address the question what so ever, but thanks anyway
  5. Jan 4, 2012 #4


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    Gold Member
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    You just need to solve the two simultaneous equations that you have at the beginning of your first post:
    Add them and then subtract them, then take the ratio to get u- it falls out in three lines.
  6. Jan 4, 2012 #5
    ok thanks ill try that
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