Coilless FM transmitter circuit


Posted on Jun 7, 2012

The RF oscillator using the inverter N2 and 10.7Mhz ceramic filter is driving the parallel combination of N4 to N6 through N3.Since these inverters are in parallel the output impedance will be low so that it can directly drive an aerial of 1/4th wavelength. Since the output of N4-N6 is square wave there will be a lot of harmonics in it. The 9th harmonics of 10.7Mhz (96.3Mhz) will hence be at the center of the FM band .


Coilless FM transmitter circuit
Click here to download the full size of the above Circuit.

N1 is working as an audio amplifier. The audio signals from the microphone are amplified and fed to the varycap diode. The signal varies the capacitance of the varycap and hence varies the oscillator frequency which produce Frequency Modulation.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Pic-plot2: a GPIB to USB converter
    Tone Control Schematic
    Precision peakvoltage detector
    Battery Tester Circuit
    Laser Power Supply Circuit
    Automatic Electronic Emergency Light Circuit Low Cost
    13.8V 40A Switching Power Supply By LM3524 and LM324 PCB
    Mcu Reset And Oscillator Circuits Applicationnote
    Tablet Reminder Uses Watch Module
    GSM Remote Control Temperature Control Schematic
    +5V, 1A DC output flyback switching power supply circuit TOP100Y
    Consumers spark a resistor-capacitor circuit
    Thyristor overcurrent protection circuit 2
    XTR101 bridge input voltage excitation circuit diagram
    AF locked loop circuit diagram



    Top