In this project, let’s learn how to make a simple “Long-range FM transmitter” at a low cost using minimal components. As you can see in the diagram, the circuit is simple, easy to build and test. Let’s begin to build our long-range FM transmitter.

How To Build a Long Range FM Transmitter

The use of transmitters that have a more powerful output than the ‘flea-power’ are sometimes required when there are many obstacles in the path of the surveillance transmitter and monitoring station receiver or the distance between them is too far so as to make a low powered device feasible. Whereas a typical micro transmitter will produce an RF power in the order of just a few milliwatts, i.e. a few thousandths of a watt, the VHF-FM transmitter described has a power output of between around a half and 2 watts, depending on the power source, which may be anywhere between 6 volts and 30 volts d.c. The battery or batteries should be of the alkaline high power type since the current drain will be found to be relatively higher when compared to the micro transmitter current drain. The power output of this device is somewhat proportional to the current drain and so, therefore, both may be decreased by altering the value of R6 to higher resistance, or a variable resistor with a value of around 1k may be introduced in series with the existing R6, so as to give a variable power output. The variable resistor must not be a wirewound device because this would act as an inductor which will cause feedback problems. The audio input to the power oscillator, which incidentally is formed by TR2 and associated components, is derived from a piezoelectric microphone which drives the simple audio frequency amplifier TR1. The input of the audio amplifier is controlled by the gain pot R1, which selects the correct amount of voltage that is generated by the piezoelectric microphone, then connects this signal to the base of audio amplifier TR1 via C7. It may be found that there is insufficient housing space for a bulky piezoelectric microphone, so with a slight modification to the circuit, it is possible to employ an electret microphone insert as shown. Since the RF field that is generated by this transmitter is relatively large, the problem of RF feedback may very well be encountered. This may be overcome by placing the transmitter inside a metal enclosure, keeping all internal wiring as short as possible and the aerial wire.

Component listing for 1-watt transmitter

Resistors Semiconductors R1 = 27k TR1 = BC547 R2 = 330k TR2 = 2N2219 fitted with heat sink R3 = 5k6 MIC = piezoelectric microphone R4, 5 = 10k R6 = 100R

L = 6 turns 22 gauge enameled wire wound on 3⁄16″ former


C1, 2, 3 = 330 pF C4 = 2–10 pF trimmer C5 = 4p7 C6 = 1 nF

C7,C8 = 40uF/25V Electrolytic

Circuit diagram for Long range FM Transmitter

Long range fm transmitter circuit

So we’ve seen the circuit diagram and how to assemble a long-range FM transmitter. In the meantime, you may also read about our 2KM FM transmitter circuit and also if you got free time, try our 200M FM transmitter as well.

We have published lots of radio transmitter circuits, which will help you learn a lot about basic communication electronics.  If you still like to work on more circuits, I will suggest a medium power FM transmitter circuit and also our versatile FM transmitter.


Great! You now have a handful of circuits to play with for at least 2weeks. Try all our circuits and let me know your feedback. FM transmitter circuits are a good starting point to learn basic communication engineering principles in electronics. I hope you enjoy the learning process. 



  1. Jonathan

    I have a lot of harmonics, is that normal for this design?

  2. What is the correct value of R6 and R3? Thanks.

  3. D.K. Lourembam

    May I use this circuit by adding one Final R.F. Amplifier leading by 2N3866 at the output of this circuit as a long range Transmitter.

  4. What will be the coil diameter?
    What you mean by 3/16″ former?
    Please reply if any one knows

  5. how many km works these circuit pls reply frnds

  6. Jay Jongko

    The piezoelectric mic needs a supply voltage to operate. In this circuit, in my opinion, we need to add a resistor connected from the + of mic to the 12volts supply in order to complete the entire operation.
    Btw, thanks for this useful circuit. and indeed, I used it as a reference for my own project.

  7. JAmes white

    Thanks for the circuit diagram. The transistor use in the diagram like 2219 is not in my country how can I get some from you.pls reply me as soon as possible I needs your friendship. Thanks I am from Liberia west Africa.

  8. Harsh Verma

    Use 2n3904 transistor in place of TR1 and remove r1 and place + terminal of mic to the base of TR1 and also use 100 pf variable capacitor to get clear sound. And also you can use bly81 or blx65 in place of TR2.

  9. semixH2s04

    Nice work like,how many feet of antenna can be use to give up to 2km range.

  10. Daudi Sulemaani

    Teacher, radio propagation principle says – if electricity is vibrated in a wire at 10kHz and above, those Radio Waves created will are continuous and will be picked even behind hills, why then FM follow line-of-sight yet MW,SW,LW won’t? Thank you. From Ugamda.

  11. Daudi Sulemaani

    Teacher, why FM receiver will not receive faraway stations as AM does yet FM transmitter vibrates at more than 100mhz? From Uganda East Africa

    • Seetharaman

      High RF frequencies travel in straight line. to receive the signal line of sight is important. since earth is curved during favorable conditions it can reach 60 to 150kms depends on power and height of transmitting and receiving antenna. AM signals in MW band are transmitted through ground wave hence they can reach longer distance During nights they can travel 1000s of kms. you may get lots of distant stations during nights in your MW AM radio.

  12. Gaju jayebhaye

    Sir this ckt making or redimed where are avilable in market and how many ruppies

  13. I have already made it. But it’s sound quality is very poor. so much noise………

  14. Seetharaman I want to add a crystal to the circuit to make the frequency stable. Where can i connect the crystal

  15. I have a question that at which frequency i should tune my radio to hear from it tell me please i want to use my small mobile radio to hear that it is working.

  16. Rajib saha

    Have you solved Mr. Avdi?
    This is a feedback capacitor which has been connected between Emitter to collector to keep oscillating the tank circuit (Coil and Capacitor). You can use any disk capacitor between 4.7pf to 10 pf as a feed back capacitor.
    You are Lucky because you are from Texas, you can buy BH1417 stereo FM IC and 7.68 crystal to make very very perfect radio. It is very simple. But I am far from America or Europe, so I never found this IC and crystal.



  18. can any one tell me at what frequency does the above transmitter transmits the data….???

  19. sir, i want the clear explanation of signal transmission in communication oriented circuits. and i am waiting your favorable replay . thanking you

  20. arp ridwan

    resistance have two pole.
    How can i connect resistance R1…?
    please reply to me….

  21. Have you solved Mr. Avdi?
    This is a feedback capacitor which has been connected between Emitter to collector to keep oscillating the tank circuit (Coil and Capacitor). You can use any disk capacitor between 4.7pf to 10 pf as a feed back capacitor.
    You are Lucky because you are from Texas, you can buy BH1417 stereo FM IC and 7.68 crystal to make very very perfect radio. It is very simple. But I am far from America or Europe, so I never found this IC and crystal.

  22. Hey…. C4 = 2–10 pF trimmer, is not available any alternate?

  23. i need a 10 kilometer range fm transmitter circuit diagram. if it remains to anybody please send me that.
    my email:

    i’ll always greatful to you.


    I MAID THIS PROJECT SUCCESSFULLY. WITH PROPER FREQUENCY AND STRENGTH.IF YOU WANT HELP THEN CONTACT ME ON or at 08866792042…… i will surly help you to bring out you from the problem 🙂

    • Mohammed se’ad

      I want to make 3 to 5km transmitter how can it be ? I need ful info … Plc replay on my email “

  25. is it in the commercial band (88-108mhz)? how i have to make the coil?

  26. Munib Ali

    I am student Of Electrical Engineering Sir Tell me About Which Antena I used This transmitter and
    2nd tell me About Its Case

  27. Sanjiv Nepal

    How many cost it takes to make it complete?
    What do you mean by 6 turns 22 gauge enameled wire wound on 3⁄16″ former?

  28. gaurav tomar

    sir, i am a student of electronics and communication engg. i want to established a low power 1-2 km. fm transmission station in my college campus. I am authorized by my faculty to working on this project. they will arrange for license of Fm. so please give me appropriate guideline for this through mail @

  29. seetharaman

    Hi Raja use it through the USB port available on your Laptop.


    i want to use externel cd rom with laptop. can u tell me about this.

  31. I need fm transmitter am from Ethiopia and want to transmitte some info to my vilag farmers. I have been trying to mack fm transmitter befor two times i fell to mack it real
    If you have 100% workig project, you can mack my Drem true.
    Send me at

  32. can anyone please let me what should be the inductance of L thanks

  33. ali maqsood

    can anyone plz tell me what type of oscillator is this thanks



  35. seetharaman

    Hi Simon you can use 1/2 wave length dipole for directional radiation and for omni-directional radiation 1/4 wave length whip antenna (telescopic antenna of suitable length can be used)


    hi everybody,
    I need the steps to make my own fm transmitter so
    if intrested means someone can help me

  37. Hi ZIDDIK… I want your circuit.. Your mail id please…

  38. It’s really great experience to work on above fm trasmitter circuit diagram. it’s having quite good frequency range…..

  39. Bogus Dude

    C8 listed after C3 SHOULD NOT be their
    The correct C8 is listed after C7

    C5 can also be a: 47pF
    C6 can also be a: 0.001uF

    R1 27k– is that correct?

    TR1 can be substituted with a 2N3904

    L – a 3/16″ drill bit will work fine for this

  40. Hi Master
    I need a 10km range fm 88-108 mhz transmitter please send me some detail or much better if you can provide the circuit diagram and the component list please just mail it to me at thanks and more power.

    From Alone
    Johore Bahru Malaysia

  41. did anyone try this circuit? I want build it and also i have build a 100 meter range transmitter with only one bc547 transistor n it works perfectly with high clarity sound output!! If any1 want the diagram just mail me



  42. Programming

    Hi there, You’ve done an excellent job. I’ll certainly digg it and personally suggest to my friends. I am confident they will be benefited from this web site.

  43. Hi, I am looking for a 15v 1.5Amph smps circuit diagram and googled a lot and end-up with nothing. If any kind heart can help me on this, i will be very much thankful. Thank you verymuch in advance..

  44. Vaseem Mehran cp

    Nice circuit.its worked very well.

  45. Seetharaman

    Hi Avdi use 2nos 10pf in series to achieve 5 pf which is ok for C5.

  46. HI i buy 2 FMtransmitter kit 1[KIT32] and 1[K18V2] but after i insatal all parts on bord , nothing no workin i install parts on bord 100% good,,but i think maybe they sale wrong parst or damaged alectronickit,now i m buildin one nother with 2Transistor2N2222,,,but i can t find ceramic disc 4p7,,so can sameone help me,,what i can use inplace 4p7, i have ceramic disc 5,i have 10,,i have 18,27,33,68.102,103Z,104Z.. but 4p7 no have no wher stores,,frys electric radishack no have,,, I M FROM TEXAS USA

  47. Daniel Akan

    i want to to program a micro controller to work on the traffic light can you help me

  48. can we extend the range by using a diple antenna

  49. can we extend the range by using a dipole antenna

  50. Can you tell me if there any circuit for generating Train Horn like sound and which can be implemented on My Bike.
    Input Voltage Supply Should be 12VDC.
    Thank You.

  51. Seetharaman

    Hi Sanjay this transmitter itself can be used with dipole antenna to achieve 2kms.
    Hi Ravi what is the frequency of operation you require, AM or FM omni or uni directional.

  52. ravi ranjan

    i m a btech 3rd year electronics and communication engineering student..
    i want to make a radio station at our college for our tech fest only..
    will u elp me with the circuit by sending it 2 me…
    i need a transmitter of nearly 2km range..

    waiting 4 your prompt reply..

  53. Hy,i am sanjay please inform me about 2km long rang but easy circuit of fm transmiter. Please mail me.

  54. hi, i want to make a transmitter project for educational purpose. can you please help on this? please email me the circuit and detail at

  55. seetharaman

    With a whip antenna of wave length / 4 you can cover minimum 1/2 km distance.

  56. seetharaman

    Hi Favas you can tune this transmitter in frequency range of Band I, Band II and Band III (between 50 to 250MHz)

  57. seetharaman

    Hi Favas sorry for this long silence. this transmitter will operate in VHF say 65 to 200MHz. Since we have with us broadcast band receivers operating from 88 to 108MHz. we can use them to monitor by tuning our transmitter to this frequecy range.

  58. hey hi…i want to make a transmitter receiver project for educational use.can you please help me on this.please email me the circuit and detail at

  59. Seetharaman

    Mr. Kulla you make a small variable trimmer yourself. Take 0.2mm insulated wire 2″ length each. connect one to one end of the coil and the other to other end of the coil. now twist them closely tightly (like twin twisted plastic wire-not electrically connecting them). Now you can expand compress the coil ‘L’ to acheive the required frequency.

  60. i see… thank you so much.! this really helps… can i ask another question? can i substitute the trimmer capacitor with another kind of capacitor (as in electrolytic or mylar).. the local electonics stores here dont have trimmers..

  61. hi.. i hope the admin would read my comment.. im a neophyte when it comes to electronic circuits, but i just want to ask this question. the r1, which is 27kohms, has only two ends right? so why it is that there are three components connected to it? 2nd question, what does a piezoelectric microphone do? piezoelectric means electricity by means of putting pressure on a thing..

    pls answer me, i need to be guided.. thanks.

    • reply to kiLLua
      R1 is a potentiometer and it has three terminals (two end terminals and a wiper terminal).

      Piezoelectric microphone will produce an output voltage according to the sound waves falling on it. It converts the vibrations caused by the sound waves into a proportional electrical signal.

  62. if anybody needs help,add me in skype:mukba16 or in nimbuzz:nika92
    i am constructor and i have tested this schems…

  63. Hi i’m a daily reader of circuits today, and i’m in love with ur site, many many thanks for ur hard work and for such wonderful and useful circuits

    But anyone tried this circuit and is it a success?


  65. Circuit Diagram

    Yes it is a good FM transmitter, 2N2219 is a RF transistor and I saw it in many high power FM transmitters.

  66. jeya kumar

    fm transmitter circuit ;plz give me the distance to transmit and make the circuit……plz reply……thanks.send reply ……

    • This circuit has a range of about 1.5Km at full supply voltage.

  67. jeya kumar

    how much distance i can transmit .its frequency range

  68. can i have the reply asap.., plz,.,., i need it to make my project,.,.,tnx,.,.,.

  69. wat typ of antenna should we use for this circuit and how long should it be????

  70. Manoj kumar

    Hi there,i am a daily reader of your site,circuitstoday.I just want to know,what is the distance covered by using the above LONG RANGE FM TRANSMITTER.Plz reply me or better mail me!Thanking you.

    • At full supply voltage it will cover up to around 2Km. For maximum performance you need a good power supply , matching antenna, correct inductors and a very efficient PCB.

  71. Suraj Prem

    Will it help in increasing FM range inside the house.

    • This transmitter is powerful enough to be used in a house.

  72. i need 100Meter range FM transmitter cct. diagram

  73. i need 100Meter range FM transmitter cct. diagram.

    • a lot of FM transmitter circuits are here.Pls look in the radio circuits category.

  74. Hi Master i need an FM transmitter cct. diagram to cover the range of about 1000 meters in my village.

  75. Ineed a fm radio schematic without any IC. thank you from fagh

  76. thujiya aii la zhavla phandra hattii with 12 bulli

  77. Tende ivo

    can a variable capacitor be use for trimmers?

  78. myokoko (myanmar)

    I live in Myanmar.The transmisson licenses aren’t tight here.I want a FM Transmitter with a
    wattage of up to 4-watts to transmitter as an
    amateur.Could you help with this?Thanks!

  79. myokoko (myanmar)

    I live in Myanmsr.The transmisson licenses aren’t tight here.I want a FM Transmitter with a
    wattage of up to 4-watts to transmitter as an
    amateur.Could you help with this.Thanks!




  81. Sunny : What should be the value of C7 and C8?
    I think they are disconnected terminals ,right?

    Author:Thanks for pointing the error.I have added the values of C7&C8 in the parts list.Please check.

  82. how much distance i can transmit .it’s frequency range

  83. Khasru:can i use it for radio transmission.

    Reply: You are from India.I figured that from your name.Sorry my friend,you can’t use it for radio transmission. Any sort of radio transmission without proper licence is punishable in India and of course in most of the countries.For educational or study purpose you can make radio transmitters,thats quite OK.But continuous transmission over long ranges will invite trouble.If police came to pick up your transmission in their wireless or any body files a complaint against you ,that will be trouble.If you are regularly transmitting,they can easily track the source.