TV transmitter circuit

Description.
The TV transmitter circuit given here uses UK standard 1 FM modulation for sound and PAL for video modulation. The audio signal to be modulated is pre-amplified using the transistor Q1 and associated components. The transistor Q2 has two jobs: production of carrier frequency and modulation. The pre-amplified audio signal is fed to the base of transistor Q2 for modulation. Capacitor C5 and inductor L1 forms the tank circuit which is responsible for producing the carrier frequency. The video signal is fed to the emitter of transistor Q2 via POT R7 for modulation. The modulated composite signal (audio+video) is transmitted by the antenna A1. This TV transmitter circuit can be operated from 12V DC. Either a 12V DC power supply or a battery can be used for the purpose, using a battery will surely reduce noise and improve the performance. If you are going with a DC power supply, then it must be well regulated and free of  noise.

Circuit diagram with Parts list.

tv-transmitter-circuit

Notes.

  • Assemble the circuit on a good quality PCB.
  • Inductor L1 can be made by making 4 turns of 24SWG enameled copper wire on a 6mm dia: plastic former.
  • T1 can be a radio frequency transformer with built in capacitor. (Can be found on old transistor radio boards).
  • Antenna A1 can be a 1M long copper wire. (Experiment with the length to get optimum performance).
  • This transmitter is working in VHF band somewhat between 50 – 210MHz.
  • This transmitter is compatible only with PAL B and PAL G systems.
  • Slight adjustments are required on the value of C8 for getting optimum performance.
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131 Responses to “TV transmitter circuit”

  • muhammad says:

    Hi sir. I have RF modulator with 90db made for CATV. Where should I connect the output into the circuit? My purpose is to transmit video around 1km. Any transistor need to be changed? Thanks before.

  • rin says:

    Sir, can we use video signal from laptop from a vga to rca cable as a video source?

    • Seetharaman says:

      it should be 1volt pk analog video signal.

      • saad says:

        can i use and modify a webcam as a video source .?

        • Seetharaman says:

          Hi Saad Please see reply dated 5th Jan 2014 of Mr. Prince.
          Hi Muhammad CATV amplifier are for boosting the signal in cable TV to 1volt pk signal. you can not use it as an RF amplifier to drive an antenna for which you require a RF power amplifier.

  • sivanesh bala. says:

    sir. any antenna will need in receiver side or ….

  • prince says:

    please can I use an external web camera as the video in and a carbon microphone as the audio in thanks

    • Seetharaman says:

      Ensure the web cam is capable 1 volt pk video information if less add a suitable amplifier between camera and video input. you can use a carbon micro phone with suitable pre amplifier to produce an audio input of at least 1volt at the audio input socket.

      • prince says:

        please which amplifier can I use if I can build it please help me with the diagram for the web camera n carbon microphone

  • pritam rit says:

    what is tha value of l1 and t1..plz rply

  • virender says:

    Dear Seetharaman, I want your help in making Automatic Room Light using AT89C51 Microcontroller. I assembled the circuit based on two ir sensor, two ic 555 and two visitor counters. Every parts is ok but the circuit is not working. I do not know how to use source code. I never worked with microcontroller. But I want to make Automatic Room Light controller. Can you help in this regard please! With thanks!

  • sata2012 says:

    Hi all,
    Who built this circuit?
    Which parts of the circuit should be changed to optimize the output?
    To increase the frequency to 500 MHz, what parts should be replaced and what elements should be?
    Please answer.
    Thank you very much

    • umakant says:

      I realized the circuit but got very poor results. I would suggest you to try some different circuit or maybe purchase a RF converter kit and do reverse engineering.This circuit will not give optimum results without a RF amplifier{not tested).Anyway why go in UHF range? it will only complicate matters of impedance matching and antenna interfacing.And if you are short on time(I was), purchase a wireless camera online at robokits.co.in.

      • virender says:

        Dear Umakant, I have not enough knowledge in electronics. But I will definitely tell you what I did in this project. I simply made this circuit without audio as given above because I did not find T1 (IFT) so I connect the simple FM Transmitter with it. But still I did not test it with audio but the transmitted video is very clear. I removed the trimmer C5 and using the fm gang condenser to tune it easily. And, I took the copper wire from the cable TV coming out from the house and wind it four turn on telescopic antenna of the codeless phone. I also changed R5, R6 with 1K and using Nokia cell phone charger. I hope this will help you. I am sorry for the poor English.

    • Seetharaman says:

      Hi Sata increasing the space between winding will increase the transmitting frequency (and also by reducing the value of C5)

  • umakant says:

    hi, is c8 27 pf or 2.7pF?
    I did with 27pF and i m getting extremely poor,unstable picture.Please reply soon.will air former for l1 cause huge losses?

    • Seetharaman says:

      Hi Umakant L1 is self supporting air core coil. you can wind it on a pencil slide out and use it. the windings are close wound. latter for tuning you can expand the winding little(small gap between each winding). C5 you can use oscillator section of PVC2X.(around 45PF) C8 can be anything between 2.2 to 27PF. Alternately you can connect Antenna directly to L1 tap at 1/2 turn from supply end.

  • dhanasekar says:

    can we receive it using dth receiver

  • virender says:

    Dear Seetharaman, I build this TV transmitter circuit. But the video is not stable and the screen goes up and down. I tried to control it using the V-hold control of my TV but the result is same. Please help to solve this problem. And also please tell me how I can increase its video quality. With thanks in advance!

    • Seetharaman says:

      Dear Virender First check your power supply is of good quality with least ripple. if your power pack is ok, you may be over modulating, you may correct it by adjusting the video modulation control R7. This should solve your problem.

    • umakant says:

      hi virender i m also working on same project.How to make l1?

    • umakant says:

      Hi Virender,can you help me regarding few stuffs related to this project?

  • parakrama says:

    how many range in this TV transmitter circuit?

  • dananjaya says:

    hello sir,
    i like to make this but i know more…
    so, plz tell what transformer (t1) needed for this sellers ask for what transformer what is that tranformer if cannot buy it in marcket plz tell me what can i use for it?

    thanks.

  • virender says:

    Dear Seetharaman, Can you please help me in receiving cable tv signal video wirlessly on Laptop with usb fm stick (tv tuner). And also please send me the related circuit. Any reply shall be highly appreciated. With thanks!

  • Shaun says:

    What is the RF power output of this circuit?

  • deni purwanto says:

    excuse me sir,,,
    where can I get the pc board and components of this circuit?
    I’m from west Kalimantan,
    thanks…

  • sri says:

    sir, if i design this circuit is it suitable for recevie signal in our country tv receivers

  • sagar thapa magar in nepal says:

    how we make a longe range transmitter?

    • Ben Smith says:

      If you were to link the output of the board to two (2) FM booster circuits in series with each other, then you can output up to around 3 miles.

  • raja says:

    sir,which type of transformer using television transmitter. i need 2 kilo metre audio and video transmitter circuit diagram

  • Sahil says:

    Hi If I build this TV transmitter circuit then how can I buitd TV receiver. PLZ hlp

  • vysakh says:

    i also felt some trouble with this ckt. no audio nd very poor picture quality

  • Sylvain says:

    I just released this circuit but audio part is not running, advice me what to do because i lost required frequency transformer, can i released other audio circuit and combine them after? if ok, tell me how to find that circuit. Thx!!!! still waiting ur best answer

  • KALPESH says:

    can it is possible to work properly ?//??

  • John says:

    i already released his circuit but is running but pictures are not stable and sound is not being received or transmitted what are the solutions to resolve this problem please advice me what to do.

  • Bosco says:

    hi! i already released this circuit but is not running i thing the problem is final oscillator capacitor and coil if possible sent to me images of coil to be used is it air follow or it has other material inside? plse help me

  • seetharaman says:

    Hi Sylvain the final oscillator imedance will get affected you may have to change capactors, hence follow the given circuit

  • Sylvain says:

    any matter if i replace R5 and R6 by 10k? what is their importance? pls help me!!!

  • Sylvain says:

    hi help me to know how to calculate BW(bandwidth) of this tv transmitter (mathematically), its operation range and its power if possible send to me a full document on bivain2020@yahoo.fr thx

  • Sylvain says:

    please help me by sending power amplifier of 20watts that i can use to transmit up to 10km until now i am still searching but not find or send to me a precise link thx!!!

  • Sylvain says:

    please help me

  • Sylvain says:

    1.i visited all given links but i need that you precise which circuit can i use to transmit up to 10km,or send it through my e-mail if u have (bivain2020@yahoo.fr)

    2.Now the circuit is running at short i need to improve how can i send my name in so that it can be received with transmitted video on top of tv receiver,try to send to me a circuit

  • seetharaman says:

    HI sylvain the following is the best suited rf amp after above circuit for you. connect C8 signal to this amp instead of antenna.
    http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=23051

  • seetharaman says:

    Hi Gerald check you power supply for regulation. check for your modulation level it may be too high. finally if transmitter drifts when your hand is close to antenna reduce C8 to 2.7 to 4.7 PF.

  • gerald says:

    i built this cicuit and it worked out but the frequency was going on and off. what could be the problem please help me. dont mind my english.

  • Sylvain says:

    Hi Hi!!!!! In my country is not illegal, so advice me amplifier to use by sending precise link where i can find it because sent link i find many and i miss how to choose which one is compatible, is helpful i you send a full circuit i can use, thanks

  • seetharaman says:

    Hi Sylvain in India it is illegal.
    you can go through lots of designs are available.
    http://www.dxzone.com/catalog/Technical_Reference/Amplifiers/VHF_Amplifiers/

  • Sylvain says:

    help me by sending circuit that can used as tunable amplifier of 20to30watts through my e-mail,thanks!!

  • seetharaman says:

    Hi Sylvain you have to use high power RF Transistor in class C mode with tank and aerial tuning unit after Q2 and tune it with SWR meter etc. it is not under the purview of this article. you require licence etc.

  • Sylvain says:

    Please help me!!

  • Sylvain says:

    Tell me more about amplifier, can i use audio amplifier of 30watts made with TDA2040 with frequency limit of 100khz you presented in audio amplifier? pleas help me i need to implement this 10km tv transmitter, thanks!

  • Sylvain says:

    what are the requirements to release the circuit said to operate up to 10km? any modification to the circuit presented or only addition tunable amplifier is added? transistor used are BC547 or 2N2219? whit type of antenna used to this circuit?

  • Seetharaman says:

    Hi Sylvain All capacitors can be rated for a minimum of 16 volt. Standard video signal maximum of 4MHZ.

  • Sylvain says:

    and what era the voltage rate of c1 c12&c5

  • Sylvain says:

    what is the range of frequencies of video signal in this tv transmitter?

  • Seetharaman says:

    Hi Sylvain C1 10 & 12 are electrolytic. C5 is variable capacitor (trimmer capacitor) all other capacitors are ceramic disc type. (you can use Philips Pin up or ceramic tubular capacitors also)

  • Sylvain says:

    here c1,c2,c3,c7,c9 are which type of capacitors,is it ceramic or electrolytic?? please help me!! is very needed.
    thx

  • hello sir
    i want to make a video transmitter circuit and a receiver for my project would u help me in giving the basic idea and how to proceed..?
    sir
    basically i want to know everything of each component so please send me data sheets or ref sites
    thank u sir

    Read more: http://www.circuitstoday.com/tv-transmitter-circuit#ixzz1OOXNWohS
    Under Creative Commons License: Attribution

  • Sylvain says:

    i need to know more details about capacitors used in this tv transmitter each with its relative voltage rate examples c1=10uf/16volts thx

  • Seetharaman says:

    Hi TSU TV set audio take of IFT

  • TSU says:

    what can we use as a substitute to the T1?

  • Seetharaman says:

    Hi TSU yes it is same

  • TSU says:

    hi! i just want to ask if this circuit is the same with A/V transmitter?

  • AVDI says:

    HI
    who can explain me about this tv transmitter,what parts is T1,,is transformer or what part,what i can replace with T1, how far is range for this TV transmitter..THANKS

  • Sylvain says:

    i need more details about this tv tx and how long distance to be used

  • gnanendra says:

    hello sir
    i want to make a video transmitter circuit and a receiver for my project would u help me in giving the basic idea and how to proceed..?
    sir
    basically i want to know everything of each component so please send me data sheets or ref sites
    thank u sir

  • Seetharaman says:

    Hi Benravin Yes this will work in india only T1 to be tuned for 5.5mHz instead of 6MHz (FM sound carrier)

  • BenRavin says:

    Can i use this transmitter in India? Will it work in Tv receivers ?

  • Sadik says:

    I made this Circute but it is not working good, I have a doubt in Power using, how many Ampier we can use. I used a Regulated IC 7812, I don’t know how many ampere use please help me in problem,

  • gerald says:

    what type of antenna should i use for such a circuit?

  • hb says:

    hello seetharaman…. first of all i am a fan of u and of circuitstoday…no better website than this for hobby projects….main thing is u people are responsive to requests and i also u dont steal circuits and post them blindly but you work them out,and study them before posting,u are doing a real great work.

    i would like to know that if it is possible to transmit comp usb data via any digital modulator circuit over the air and get it received by demodulator…i dont ask for any high speed lan type of performance but even simple hyperterminal would do…or maybe atleast ability to transfer data between two pcs but by our own made diy circuit…and how much challenging it would be..
    thankyou
    hb

  • Avdi says:

    HI Seetharaman THANKS
    Can eplanin me more about,ceramic capacitor disc,UF ,PF,N i dont know which is big size,or big voltage,,,i see ceranic disc have 3 kind color ,,red .green.blu..same example here,B103K, B472K.B181,,151J,,681J.,i cant understand about this,how i can chack part is good or bed,what kind multimeter,can chack,ceramic disc.
    I dont know for size of rasistor,which is big [K] or [OHM] or [M] i need to learn more,i just start to learn.
    THANKS

  • Seetharaman says:

    Hi Avdi for ceramic disc capacitors there is no polarity. there metal discs and ceramic insulatotors are stacked alternatly. they are not wound hence no inductive component involved,due to which they are most suitable for high frequency circuits. but they are available in low values upto 2uF votage from 12 to few kV. normally text will be on one side and the other side will be blank. same resistance code type but written in numerals. say 104 means 10 X 10 to the power four PF. 101 means 10 X 10 to the power 1. that is 100PF etc.

  • Avdi says:

    Hi can sameone from you,can explain to me,,about ceramic disc,,i dont know ceramic disc ,which side is + -or thet is go which side have text on it.
    THANKS

  • Seetharaman says:

    Hi German Connect C4 to ground instead of audio modulation transformer T1
    The circuit from audio in to R4(incl) not required.

  • german says:

    Hi, if i need only video transmition i hae to cut de picture and remove audio side including t1, r4 and c4?

  • seetharaman says:

    Hi Sarvesh In 180deg you will have 2 lugs these are conected internally and to be connected to supply and the single lug between them is the variable plate should be connected to Q2 collector

  • sarvesh says:

    i m having difficulty in connecting capacitor “C5″ .
    This variable capacitor is actually having 3 legs. & in circuit diagram it is shown with 2 legs only . So plz explain me , how to connect these 3 leg capacitor “C5″ in the circuit.

  • seetharaman says:

    The capacitor other leads should get connected to common negative supply line.

  • NASEEF.KK says:

    pls help,i want to connect the AV cable of DVD to my PC. i got a AV to USB cable from market.but cannot watch it.
    it want any driver softwear? help me

  • NASEEF.KK says:

    i cannot get 2N2219 transister any where.pls advise other same value transister.how create power amplifier with tuned circuits? pls send the circuit diagram.
    pls look to circuit as Capsitor 3,11,12.it’s other leg where to be connect? it is free ? or it is earth?

  • seetharaman says:

    Hi Dedi BC 547 can be used for projects upto 100MHz.

  • dedi says:

    sir,

    is the BC547 very high frequency transistor ?

    because i often use this transistor as a switching transistor. This transistor is a cheap transistor. Can i use this transistor to build oscillator in radio circuits.

    sorry, my english isn’t good

    thanks

  • seetharaman says:

    Hi Naseef it is an RF power amplifier with tuned circuits. You can use any good RF amplifier with say 20Watts RF output for your project. i dont have one check in the net

  • Naseef.kk says:

    sir,
    what is tuned power amplifiers ? how create it?
    can i buy from electronic shop? how add tuned power amplifiers from the collector of Q2?
    i expect your valuable reply

  • Gva says:

    i want minimum 3.Km TV Transmitter circuit pls Help me.

  • seetharaman says:

    Hi Naseef You may have to add tuned power amplifiers from the collector of Q2.

  • Naseef.kk says:

    how can rise TV transmitter circuit frequency to wide area,as 10 Km.
    pls reply

  • seetharaman says:

    Hi Naseef We are not supposed to radiate signal beyond our compound, beyond this is illegal in most of the countries.
    By increasing power you can achieve better range, less noise and better clarity.
    By increasing frequency nothing can happen to range.
    A vertical whip antenna is to be of one forth the wavelength. This is antenna theory a small fine tuning is required to improve the radiated power.
    You can also use two folded dipoles one above other at right angle with the transmitter, To have a coverage of figure of eight.

  • Naseef.kk says:

    sir,

    “(wavelenth of the frequency divided by 4). to optimise the output radiated power.”

    pls describe above line,as it is your statement.

  • Naseef.kk says:

    sir,
    thanks,
    1.when i rise circuit frequency to wide area,will get full clarity in vedio and audio?
    2.how much KM distance we can rise maximum?
    3.any illegal problems for the TV transmitter by POlice or Govt

  • seetharaman says:

    Hi Naseef Try by replacing Q2 with 2N2219 change R5 and R6 to 10K and emitter resistance of Q2 1K pot to 100 ohms carbon pot. use a 1.5 meter telescopic whip antenna try by varying it length (wavelenth of the frequency divided by 4). to optimise the output radiated power.

  • NASEEF.KK says:

    how can rise TV transmitter circuit frequency to wide area,as 2 Km.
    pls reply

  • seetharaman says:

    Hi Daniel you can use any PAL set you can tune the oscillator to cover old turret tuner’s Ch 2 to Ch 12. Band I ch 2 to 4
    and Band III ch 5 to 12. T1 can be SW 5 pin oscillator coil or old sound card input transformer 5.5MHz or FM IFT with additional capacitor to tune to 5.5MHz.

  • nara says:

    John! In old transistor radio board I found there are couple of T1 type radio frequency transformer. Could you specify which one of them, red, yellow, white, as these IFT transformer have different capacitor value

    thanks

  • daniel says:

    I want to know if this can be receive by an ordinary tv set, and on what channel? so it won/t work on NTSC system?

    Thanks

  • daniel says:

    I want to know if this can be receive by an ordinary tv set, and on what channel?

    Thanks

  • seetharaman says:

    Hi Rajesh use a pocket FM radio with TV sound to check the frequency, or directly connecting it to your tv and search tuning it and get the frequency.
    Hi Govind Chinese make simple pin hole camera without flash for 35mm film is available for less than IR100.00 in the market. Tell me your specs. i will advice.
    Hi Raj you can use Solar photo voltaic cells, wind power generator, hand crank generator(have you seen the latest philips LED torch light with hand crank charger-environment friendly). You may fit dynamos to all these fintness centres, the human energy wasted there can be utilised in a better way – hey not joking i am serious about it – do you remember GD Naidu has done it for watering his garden)
    Hi Farrukh the video input can be from you vcd player or from video camera or from any video source. any tv set can be used.

  • Farrukh says:

    can u plz tell me the input from video side?
    and also the circuit for receiver or any other easily available circuit which could be used?

  • raj. says:

    i want to rise the voltage from 3v to 12v.without use of transformer.pls provied ckt diagram.

  • raj says:

    how i cant generate electricity from simple method.

  • Govind says:

    hi what is the min cost of anolog camera plz help…. and camera model no.

  • Rajesh says:

    How to least the freqency of this ckt abt 30m

  • seetharaman says:

    Hi you can get it from any old fm pocket receiver. or from a sound if board of a old tv.

  • Rajesh says:

    Where did i find R.F transformer.& what is subsitute of it

  • ujang says:

    Nice post…! Thx…

  • Seetharaman says:

    Dear Murugan you can use any camera with an analog video out put signal of around 1 volt peak. lighting level for the object and modulation level pot R7 you have to adjust to suit your requirement. Best wishes

  • LOTI URASSA says:

    I need to shara elecronics idea with you

  • sahith says:

    dude u pls give me the the receiver ckt

  • niloy says:

    Hi i need a serious help from u, how can i use usb cam (which I use in PC) as an option with this circuit? Is that possible? kindly reply,

  • raghib says:

    i need a tv receiver.any body help me if they have.
    please sent it at:

    raghib.malik@yahoo.com

  • murugan says:

    what camera is suitable..
    i need a cheap and affordable micro camera. can i use micro cam…
    pls help.. tnx
    mail me

  • adarsh says:

    here c1,c2,c3,c7,c9 are which type of capacitors,is it ceramic or electrolytic

  • anish says:

    Hi,
    What is appox. range of this TX

    • admin says:

      the range of this TV transmitter circuit is around 50-60 Meters.
      this is only a hobby circuit and is not meant for any serious application

  • twits4twats says:

    1 desmond says:

    July 9th, 2009 at 8:07 am
    all these components are not common in Ghana, so how can i get some?

    Hi Desmond

    Email these two companies and ask if they will ship to Ghana from the UK.
    rapidonline.com
    uk.farnell.com

    I think you will be plesently surprised.
    As a suggestion, have you tried looking in old TV’s and radio’s?

  • desmond says:

    what is equivalent for bf 494

    • admin says:

      BF494 is a medium power ,radio frequency transistor.In most cases it can be substituted with transistors like BC547, BC107, 2N2222 with a little compromise on performance

  • desmond says:

    all these components are not common in Ghana, so how can i get some?

    • admin says:

      All components used here are extremely common and they are available everywhere.
      BC547 can be substituted with BC107, BC548,2N2222 etc.

      Still problems?? Then comment here.I will help you.