Am modulation and demodulation trainer

Discussion in 'Wireless & RF Design' started by sgfh182, Aug 25, 2014.

  1. sgfh182

    Thread Starter New Member

    Aug 25, 2014
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    hello guys..im new here and im doing diploma in electronic commucation.....im been trying to make am modulation and demodulation trainer for my project...by using the MC1496 AM modulator and demodulator...the problem is my supervisor ask me to make variable input signal. seriously i have no idea how to make an variable carrier signal input and variable audio signal input...if someone can help me with schematic for variable signal input and variable audio signal input i appreciate it...


    [​IMG]
     
    Last edited by a moderator: Aug 25, 2014
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I notice that there should be an image, but can not see it.
    Please upload the image to the forum.

    Bertus
     
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  3. alfacliff

    Well-Known Member

    Dec 13, 2013
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    why do you need to vary both the rf input and the audio input? wouldnt it be best to hold the rf input constant and show the results of varying the modulation level? for some ham radio classes I either use a signal generator or one of my more portable trancievers (yeasu ft 817) and an osciliscope.
     
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  4. sgfh182

    Thread Starter New Member

    Aug 25, 2014
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  5. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Did you have a look at the datasheet of the chip?

    In there you will find this schematic for an AM modulator:

    [​IMG]

    Bertus
     
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  6. sgfh182

    Thread Starter New Member

    Aug 25, 2014
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    im sorry i was wrong...its true to keep the rf input constant... the aim of this trainer is to show the varying modulation index..how to create a variable audio input....is there any schematic diagram...i need to build a trainer with an adjust tool on it to control the modulating signal for the input to be varied.....thanks for the reply i really appreciate it
     
  7. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    For the carrier you would need an RF oscilator.
    For the audio, you could use a function generator.
    A function generator can change the frequency and the amplitude of the audio signal.
    To see the result, you would need an oscilloscope to show the modulated signal on the output of the modulator.

    Bertus
     
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  8. sgfh182

    Thread Starter New Member

    Aug 25, 2014
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  9. bertus

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  10. sgfh182

    Thread Starter New Member

    Aug 25, 2014
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    you're the man!!!thank you very much....i really appreciate it
     
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