FM RadioCircuit

Discussion in 'The Projects Forum' started by asoljazworld, May 4, 2013.

  1. asoljazworld

    Thread Starter New Member

    May 4, 2013
    10
    0
    Hi,
    I am having trouble figuring out this circuit. I know what the tank circuit is doing, but I get stuck at the FET with the capacitor across the source and drain. Could someone please help me to understand what is going on the with FET in this circuit and what the capacitor is across the drain and source is for? Please
     
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    Last edited: May 4, 2013
  2. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    Q1 is an oscillator/modulator. The capacitor provides positive feedback to sustain oscillations.
     
  3. asoljazworld

    Thread Starter New Member

    May 4, 2013
    10
    0
    Can u tell me if the FET in the schematic below is doing the same thing?
     
  4. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    Could be. Looks like it might be a regenerative receiver.
     
  5. asoljazworld

    Thread Starter New Member

    May 4, 2013
    10
    0
    What is the source coil designed to do?
     
  6. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    What is a source coil? Which circuit are you asking about? I don't know much about the second circuit, so I'm not going to comment further on it. Maybe someone else can help.
     
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