Reactance FM modulator

Discussion in 'The Projects Forum' started by Envy, Aug 15, 2013.

  1. Envy

    Thread Starter New Member

    Aug 15, 2013
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    Hi,
    I'm trying to make a simulation of a reactance FM modulator. I've got a schematic but I don't really know which values I should use for the components.
    Also if anyone has a great tutorial for making one, it is always welcome.
    In the schematic a Clapp-oscillator is used, but I think it's also possible to use a Colpitts or a Hartley.

    Thanks in advance
     
  2. DickCappels

    Moderator

    Aug 21, 2008
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    [​IMG]
    The circuit above is essentially the same thing. Its a Colpitts and instead of a separate transistor as the reactance modulated device, the capacitance of the oscillator transistor is modulated directly by the small differences in base-collector voltage caused by the signal from the microphone.

    Additionally, if you Google Varactor Tuned Oscillator, you will find many reactance tuned oscillators.
     
    Envy likes this.
  3. Envy

    Thread Starter New Member

    Aug 15, 2013
    3
    0
    Thanks for the fast reply! Can you give the link of this circuit so I can have a better look at the values?
     
  4. DickCappels

    Moderator

    Aug 21, 2008
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    Envy likes this.
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