7 Long Range FM Transmitter

This simple transmitter can transmit FM (frequency modulation) signals more than a mile away. Adjust trimmer C9 to fine tune the transmitter and use battery as a source to minimize noise.
Part List:
R1, R3, R9, R10 - 10 kilo ohms 1/4W
R2 - 22 kilo ohms 1/4W
R4 - 100 kilo ohms 1/4W
R5 - 1.2 kilo ohms 1/4W
R6 - 47  kilo ohms 1/4W
R7 - 120 ohms 1/4W
R8 - 390 ohms 1/2W
R11 - 47 ohms 1/4W
Pot1 - 5 kilo ohms potentiometer
C1, C5 - 0.33uF electrolytic capacitor rated 25V
C2 - 22uF electrolytic capacitor rated 25V
C3  - 10uF electrolytic capacitor rated 25V
C4 - 220nF
C6, C7 - 1000pF ceramic capacitor
C8 - variable capacitor not less than 40pF
C9 - variable capacitor not less than 22pF
Q1, Q3 - 2N2222A or similar NPN transistor
Q2 - 2N2906A or similar PNP transistor
L1 - VK220J or similar RFC inductor
L2 - 3 turns 18AWG magnet wire wound in 10mm diameter plastic former
L3 - 2 turns of 18AWG magnetic wire wound close to L2 using the same core where L2 is wound. See diagram below.
2N2906A pinout
2N222A pinout
Inductor L2 and L3 construction

Note: This transmitter is for educational use only. Long range transmitter is illegal in some countries thus use it at your own risk.


  1. can you give the full cercuit board & symbols i dont understand l3 coil etc where she connected or please add more info

  2. this nice project how amazing range up to miles
    2N2222A NPN Small Signal General Purpose
    2N2906A this is not available what replacement =
    what is this VK220J

    Pot1 - 5 kilo ohms potentiometer

  3. how many watts is it???

  4. Sir I watch your circuit very nice.
    I have same equation how replacement correct or wrong please reply
    Q3 insted 2n2219
    Q2 BC 177
    Qi BC 109.
    I wait ur reply thanks my id