Build your very own small home radio station.I show you how to build a small FM transmitter 

Classic example of what we called "dead bug" construction in the 70's! The components look like dead bugs on a plate. Easy to build without relying on an etched board if you do not have too many parts in the circuit.

i just finished building this circuit. i am using it as i write this comment. Very VERY stable transmitter. the sound quality is reasonable also. i would say its low end frequency response would be 60hz or so. Love the circuit, thanks for sharing. To anybody thinking of building this circuit, it is an absolute must!

Hi, i like the way you do boards. very simple. And thanks for a very detailed description. Thanks for sharing all your experience

What I really like is the stacking of the copper clad pieces. "Islands". I never would have conceived of that. Makes DIY boards "surface mount". Sorta...;-) Keep up the good work!

I made one today and it's terrific. Thanks for the tutorial! Maybe another video explaining the transmitter and what each capacitor and inductor is doing, different values etc would be great.

Great build video, your narrative is very informative, like when you mention resistor values and how you can substitute other values to a degree. I am going to build one, just as soon as I finish my L match network ATU. Great job - Well done 👍🏼 Barnie.

Have just completed this transmitter build and I must say it works great and goes at least a quarter mile up the road from my apartment. Transmitter is located down the hall in a back room on my work desk and it still manages to transmit up the road. I used a 9-35pf variable capacitor with the 5-turn coil and it transmits at 93.3mhz which is ok because there are loads of FM stations on the higher end of the band and they interfere with the transmitter. I'm going to try and build your 3 transistor spy bug; bet I can get it over a mile!!!

works beautifully, and good audio output, many thanks

hi there , i just done this slightly diff. drew circit on pcb then cut out the islands with a dremill and drilled holes for the components , great. luv vids mate nice nights viewing , your work welcomed.

Arrrrrrggg matey!!! Nice one for this vid, I made my 1st mic transmitter from a kit last night, so looking forwards to making this over the weekend! Loads of people have had success coz the videos are great and easy to understand :) Thank you!!!

I made it and I got a very clear voice. Thanks 👍👍👍

I give you a thumbs up even though I don't understand yet. I will. Thank you.

Very impressed,..and very interesting, many thanks

Good work done I'm gonna build it and see

Great video. I am going to try and make this myself.

i just built this thing, gave it 4V and without even having the antenna connected i could pick it up outside of my apartment, and it is indeed very stable. thanks a lot sir! looking forward to what this thing can do with more volts and a proper dipole antenna.

What a dungeon it is!!! Another fantastic video😊

I believe you've done an excellent job and know what you're doing. I might also add that iron you use is exactly the right size and wattage too. Best regards from Texas.

I've just had another play with this circuit tonight. It really is great! Would you consider a follow up on this? A filter and a final amp ;) be worth making a coax dipole for it then and have some rather interesting fun. Thanks, mate. I really enjoyed this. My first RF exploration apart from crystal set radios. good work fella!

I built this over the weekend and it works AWESOME!!! A little "bassy" but still way better than a 60-75 dollar piece of crap that I'd get anywhere else.

Brilliant please keep them coming...

Thank you for this amazing video i followed your instructions and it works perfectly fine.I just have a simple question what kind of pass filter does the circuit have?

thanx alot for such an informative video

Make sure your accent is heavy so everyone can understand your English clearly. "We'll start with a copper plate board, it's not made of fiberglass, it's made of wood or something". Crystal clear to me, mate.

hello friend, your very good video! thank you I will make one soon I hope you contnue posting videos of FM Transmitter

very very good thanks john

Sir , you are the best tech guy on youtube you are an artist , may I ask this Q? can I input a microphone and speak? can that be done ?

Nice work I like it

fantastic videos !

thank you i built it and it worked although very short distance 3 miters with 9v battery, transmitting at 108mhz. how can i change the transmitting frequency to 97.3mhz

Amazing......many thanks.

Hi , Very nice video & thank you for sharing knowledge , wonder what is the diameter & length of L1 , you mention the gauge of the wire is 0.5 mm only , can you provide ua with more details about this inductor .

Great video, I like your method of making circuit boards. Question is... what is the inductance of L1 supposed to be?? "L1 Coil 5 turn" is meaningless since the wire gauge size isnt specified, or the diameter of the turns, or the spacing of the turns.

so it was much easier to learn and to do! what a pity you do not even português brasil .mas speaks well worth seeing their moves . congratulacin

Does going from 3 volts to 9 volts increase the output rf wattage and range much ?

Fun to watch.

THATS AWESOME

works very well . i stuck a 2n2219 in more output

Nice little transmitter. If you wanted to run it from a 6 to 12 dc power adapter - would you add a bypass cap where the power wires connect to radio board and maybe a series coil?

Very good transmitter! Can you make a video of band pass or low pass filter for this transmitter?

Good job! I'm really into making circuit bent toys and synthesizers. I'm interested in building a 25mile AM station. Any tips?

Wow I love this! Never have given a thought to making a board the way you put it together, looks like a great way to build the project. Do you have a link to that schematic you keep flashing on the screen, I must have missed it somewhere. Would be nice to have for building the project. Thanks.

One thing for sure: you aren't the "solder-saver" type of prototyper. ;-)

Nice video

My heartiest congratulations for your work, so neat so efficient and the layout is excellent from an educational point of view. At 24.00 you state that the collector inductor on the final stage stops the RF from making its way to the supply line. While this is true in every way, from the point of view of education to students I would have preferred if you said that the inductor acts as a load for the final transistor much better than a resistor so that the collector may fluctuate as required, this inductor must provide the DC to the final transistor while the "inductor" would permit the collector to undulate accordingly due to its high impedance to RF, and RF power would make its way to the antenna. The fact that it stops the RF from reaching the common positive supply is a secondary effect as far as I would say, but to pass on the DC and yet permit the collector to fluctuate is the primary issue here. I congratulate you on the placement of the nodes on the practical circuit to be equivalent to the theoretical drawings and any diagnosis can be easily followed. I admired your soldering ability, and that soldering iron though small it has got good thermal qualities while you are so prepared to apply flux even though your work is so clean to me. I like the way you introduced the decoupling capacitors on the positive rail final section even even though they are so close to each other. For a100 Mhz you have considered that distance to be pretty long. Congratulations once again. You are an excellent craftsman and a good teacher. It is such a pity that many teachers at some educational institutions are preferring to simulate all this on standard simulation programs. Keep your practical philosophy for the good of the students who see these videos.

What's the frequency response like on this circuit? How much of a drop is there between the carrier and the first harmonics?

gostei vou fazer ,quantos metros ele alcança o trasnmissor

I will soon build this one, great video, thanks ! A few questions however : What are the values of the L1 coil ? Says 5 turns, but what diameter ? what wire gauge ? mH ? And what is the value of the adjustable capacitor ? Thanks

if i parallel another output transistor in the circuit the output power or watts times 2 or more i need at least 5km max output

Very similar to the first transmitter I built at 13 yrs old!

Nice video but one question, wouldn't it be quicker and easier to sand the board as a whole piece before cutting rather than sanding/flatting each little island individually after cutting or is there a reason for you doing it in that particular order?

tried to make this but failed, wasnt getting any signal; i used a 22uf capacitor instead of a trimmer, and had to make a coil as i didnt have a second inductor - would this affect it?

Would you mind sharing the inductance of the L1 Coil 5 turn inductor?

Thinking of building this model, the only component I'm having trouble finding is the (L2) 1n inductor I believe you called it. This can't be a 5mm coiled inductor like seen in L1? Thanks Andy

@dazaro3, please want should or can I do to make the audio input stereo and also increase its voltage to 110v approximately. And also, can one use a 9V or 12V adapter to power the prototype

I am having trouble finding the inductor 1uh. Will it work without it? Or can I use something else instead. Cheers.

Good gravy...do you own stock in a solder company or something? Talk about overkill. You use enough solder for 5 of these things.

any advice on what material is okay to use for the board? i love the material you are using, what is it?

Sry for the n00b question, but I cannot find the answer on google When you say 1n caps, are they 1nF caps?

Hi, Really nice water-cooled table saw you used for the cutting. It looks expensive. Would you have the make/model of it or a link for it please? Thanks, James

Is there any way to use this circuit to amplify UFH frequencies to broadcast to analog TVs? I’m currently using a signal booster but it’s not the best

excelente vídeo y la forma de armar felicitaciones , mi pegunta es, tengo un pequeño transmisor AM de válvulas al vació como oscilador tiene la valbula uch81 ,como puedo transformarlo a FM y aumentarle mas potencia, dese ya gracias por su ayuda

How's that heat? Doesn't it cook the components heating and reheating?

Hi dazaro 3 -- Would a 3-5 jack with a twin cable work for the audio input, instead of a 3-core cable/flex?

How would I increase the transmission power? I suppose I canot feed more then 12V into it for more power (what parts need to be replaced so they can handle more voltage?)

First of all very nice Video!! At all I have two questions: 1.) What size does the board have? 2.) What is radius and length of the selfmade inductivity?

Can I add a usb cable to link up to my pc then stream music from that to the public?

،very naice musc ..good chois & good project

is C12 necessary?, because I'm short of a 100n capacitor

muito bom seu projeto,,,,,,,,,

can i replace the trimmer cap with 120p trimmer cap ?

Alright Daz, the two 3904 version of this circuit has been a good circuit from recollection. I look forward to doing this island version of it for a mate who needs slightly more range, this sounds ideal. I'm into rf myself so this will be a sinch to make, especially doing it ugly style. Would three metal t018 2n2222's @15v w/volt. stab seem ok as far as a combination goes ? same stated resistor on final stage ? Nice clear video , thanks.

hello, i like this. but can you buy it in the netherlands? i have build a own radio. where i wil play my music. but it can't with a cable. this is good for that. can you answer? tanx

what is the number of variable capacitor ???? need to buy one me a beginner so ......u know

mic is also a transistor so use a resistance like base baising

Very small transmiter FM 🏡 Yes I'Like 👍🤝

i want to know more about the trimmer values

Great video! Thanks for putting this up, I need to boost the signal more how can i do it Thank you

What is a 1n capacitor does he mean 1 nanafard so confusing getting parts for this project

I made this and it works great but I noticed that Q2 is over heating for some reason? Any tips to solve that one?

Hi Daz, can you tell me, is there a specific benefit in using this kind of set up with the copper base and islands in comparison with the PCB type, does the flat copper surface contribute to the Signal or is it just for easy building. ?

Greetings, you have some design of a fm transmitter with crystal ,,, thanks

what is the ticknes of L1 coil in mm

Very cool! Going to build since the dollar store transmitters are total crap! The only question I have is what value is the trim cap? It's hard to hear in the video. Thnx! :)

Starting at 24:05 you refer to inductor but say it's value as 1uF. When you show it I can read 'green black black' stripes, which is '500' - 50mH / 24:11.

Just watched your video and really liked it, makes me keen on building that one. I would prefer to buy the kit, where do I find one on your website?

Could you help me out please? I cant seem to get mine to work. I used a 4-40pF trimmer, and my inductor(L1) is a 5 turn, 4mm diameter, 5mm length which gives me 0.0588 uH inductance, so at the minimum trimmer setting the frequency should be around 107.95 MHz? And by adjusting the capacitor i should be able to drop the frequency to about 76.85 MHz. The thing is I can't pick up anything on my FM radio. The rest of the parts are the same as in your schematic so i assume the error is in one of these components or my math. Any tips on troubleshooting?

i'd like to see you do the receiver for these transmitters... your FM breadboard transmitter with divider resistors and a throttle LPF on the base of oscillator (1k, 1k divider, 5k pot) with a 2.2 nF decoupler... a 10k instead of 100 ohm; with an audio (choke) filter (from emitter) to pre-amp on the 10k etc... ... even the simple five transistor video transmitter, where the audio and video are transmitted 4.5 MHz apart with two oscillators/transmitters (with/for easy to find parts)! the same transmitter again (breadboard) with just video, just add 1k pot instead of 100 ohm and latch a diode (shunt, rather), 100 nF coupling to the 75 ohm termination resistor where a 470 μF electrolytic cap will couple the video input from an a/v cable... .... whew, now to your nail transmitter video lol!

Any chance I could get a schematic of the design? I can try and trace it but it'd be much easier for me to have a schematic :D

Hello sir, i've got a project and i'm having difficulties to start it....here is the title of my project Design and implementation of a small relaying station for encrypted digital signals. for e.g. relaying encrypted Digital Signal. (For educational purpose only!) Description: The purpose behind this project is to receive encrypted signals, decrypt and amplify (if required) these signals and then relaying the latter over a small geographical area. The project includes component like transmitter/ receiver, encoder/decoder and amplifier + any other appropriate components. The student(s) should be able to generate digital signals, encrypt and decrypt these signals as well as amplifying these signals if needed before transmitting and relaying the latter. This might involve designing a new antenna or modify an existing one. I'm not being able to figure out how to generate the Digital signal and send the encrypted digital signal to the transmitter :( . Can you please help me or give an idea on how to start the project?

Hi! Will this works at 2n2219 transistors?

Great video! Thanks for putting this up! I do have one question, is there a way to boost the transmission radius from "Roughly half a mile" to say 3-5 miles for example?

Why is a pair of resistors and capacitors used in the pre-emphasis circuit? What's the point of this? Can be replaced R1+R2 - 22k. C1+C2 - 2n. Every transmitter broadcasts in mono anyway, you also need a stereo encoder.

How did you calculate the output power ?

Which trimmer capiciter is used

you mean I will be able to catch radio for which people are supposed to pay , like howard stern?

Demais. Muito bom

Great Video! If I use a PN3563 Transistor on the RF output side will I have to change the values of any of the components?

Can you build me one that gos a few miles?

please how I can add a microphone?