Long range fm transmitter circuit,2W(2 km) 88-108 MHz frequency VHF

This is a long-range FM transmitter circuit in the VHF range. As Figure 1: Sonar with up to 2 watts, when used with a supply voltage of about 24V.

In the case of applications typically do not want a high transmission.

This circuit requires only one power supply 9V Only. If used voltage level of the power supply more than 10V.

How it works

We need a heat sink to transistor-Q2, To prevent this transistor overheating.

long range fm transmitter

Figure 1 the schematic diagram of 2W(2 km) 88-108 MHz frequency VHF/FM transmitter

First, try entering the power supply to the transmitter with the 9 volts battery rectangular (006 p).

To reduce the frequency interfere with each other at a distance innocently and another, reduce crashes hum.

If using a normal DC adapter that low quality, may have this problem.

The Horseshoe-shaped Variable Resistor (VR1) is used to adjust the strength of the audio input. The Trimmer -C6 used to adjust the frequency of the transmitter.

The transmitter is a little device Thus creating easy. In particular, it has copper on the PCB that serves as a coil-L in the circuit. It does not need wind the coil L in place assembly.

the PCB layout
Figure 2 the PCB layout at 300DPI/inch

the component layout
Figure 3 the component layout

Do not use a power supply higher than 24V. Because it can cause the circuit malfunction.

And an antenna that works for frequency use.

This circuit can be made waves at a distance of several kilometers.

Asked to take account of the law on this matter.

The parts you will need

C1, C2: 4.7uF 25V, Electrolytic capacitors
C3, C4: 560pF 50V, Ceramic capacitors
C5: 3-9pF 50V, Ceramic capacitors
C6: 10-30pF, Trimmer
R1: 120K 0.25W Resistors
R2, R3, R4: 4.7K 0.25W Resistors
R5: 82 ohms 0.25W Resistors
Q1: BC307A, Transistors
Q2: BC360/BC361, Transistors
VR1: 22K potentiometer (Horseshoe-shaped resistor)

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This Post Has 28 Comments

  1. Thank You Very Much.

  2. Hi Salim Khan,
    Thanks for your feedback.

  3. Thank You Very Much
    We can use the other transistors?

  4. Hi aliakbar,
    Thank for your feedback.
    Yes, you can use others one.

  5. Hi! Momename, pls how long can this circuit reach in Kilo-Meters.
    Thank you.

  6. GOOD day, please as a final year physics student that is interested in doing some of your works as project, can I get the full project write up on any one? PLS FEED ME BACK ASAP. THANKS

  7. I want to buy ur 2km fm transmiter priject. How much it will cist to me.from punjab india 9781709999

  8. Hello brothers and sisters, How you doin?

    Please give me detail of the circuit, specially how and where to solder/connect P1????

    I need argent response brother!!! I would like to thank you in advance!!!

  9. Hello brothers and sisters, How you doin?

    Please give me detail of the circuit, specially how
    and where to solder/connect P1???? You can find me on Viber +251912778391

    I need argent response brother!!! I would like to
    thank you in advance!!!

  10. hey… wat is the val of inductance?

  11. thanks you

  12. Hi moris azoulay,
    Thanks for your feedback.

  13. Please! Write size of the PCB, not to be mistaken

  14. hola,amigo la lista completa de componente por favor

  15. Good Day Brother & Sister,
    I want to know what is the possible modification at the input of the amplifier in able for me to connect the output of my FM10A Stereo Transmitter, Can I still received stereo broadcast with my FM10A if I hook it up in the amplifier?

  16. Sir
    I am babar
    I study Ur circuit.
    Send solution of my problem.
    If coil not make on PCB how posible instead air core if possible please how # 18/20/25 SWG AwG etc how turns & how diameter.
    I hope ur good reply i wait ur reply
    My ID
    [email protected]

  17. Can I use a air coil in place of l1 if yes then please mention me which gauge of copper wire and how many turns I will wind and the diameter too thanks in advance

  18. sir what is the value of L1 in the circuit and lengh, type of antenna

  19. Hi all,
    Is this circuit is working? Any one done assembly and testing?

  20. Hey, how can i receive its audio signals?

  21. Please Mention the size of PCB or if you can please upload the PCB file, because without proper dimensions of PCB its difficult to build.

  22. Please say the value of l1 and how many time I round

  23. Hi. I do not know how I solder on your pcb layout. So, please give the labell of your pcb layout, how to solder the R, C, P and T

  24. Can I replace the 10-30pF trimmer capacitor with 40pf trimmer capacitor

  25. hello to all
    i made that but don’t work !!
    that’s a crazy plan.

  26. what is the value of L

    1. Hi,
      It is coil on the PCB. I do not its value.

  27. please give me the more details about this circut. i mean project report

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