fm tracking transmitter circuit


Posted on Feb 7, 2014

This is a design for the tracking transmitter of audio tone in FM band frequency. The circuit can be used a signal transmitter or remote control transmitter. The circuit is use only the available components. The range of the transmitter is 100 m in the distance using 9V power supply and with a matching antenna. The circuit is built by 555 timer IC


fm tracking transmitter circuit
Click here to download the full size of the above Circuit.

for producing the audio tone and based on JFET as core the circuit. This is figure the circuit. The operation of the circuit is the first JFET (Q1) is wired as a Hartley oscillator which is frequency modulated by the audio tone. The second (Q2) JFET is wired as a buffer to isolate the oscillator based on Q1 from the antenna. The diode D1 is used as a varactor here. The diode is reverse biased by the ramping voltage produced at the pin 6&2 of the IC1. This results in the change of junction capacitance of reverse biased diode, which in turn alters the frequency of the oscillator to attain the frequency modulation. The inductor L1 can be made by winding 5 turns of 18 SWG enameled copper wire on a 3/8 inch long, 3/16 inch diameter plastic tube. The coil must be tapped at the center. The antenna can be a 20cm long wire.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    MCS08DZ60 Evaluation Board
    Transistor Checker with 555
    Digital Mixer
    laser tag game multi player
    1000 watt power inverter circuit diagram
    STK4050V audio amplifier circuit
    Full-Wave Rectifier circuit
    HIP6302V Microprocessor CORE Voltage Regulator Multiphase Buck PWM Controller
    Night Light Saver
    Transmitting Audio Streams in Automotive Applications Using the MAX9205/MAX9206 LVDS SerDes
    Wien Bridge Oscillator Design
    R5000 Computer Interface



    Top