How to make a AM Radio Transmitter
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- čas přidán 18. 04. 2017
- Here is how to make an AM radio transmitter, much easier than the FM... so enjoy! :)
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The pen I use was donated by: hobblecreekcraftsman.com
Intro Made by Tate Storey, check out his channel! : • Thing that happened to me
My multimeter was donated from goo.gl/uOGdwd
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List of Materials:
1- 1 MHz crystal oscillator
2- step up Transformer
3- 4AA battery case
4- PCB perf board
5- ( optional ) LM386 op amp
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Piezo Electric Crystal Video: • Piezoelectric effect
Induction Video: • How to make Induction ...
FM transmitter: • How to make an FM Tran...
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Twitter: @Keyst0neScience
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During my childhood, I built two spark gap transmitters out of two car ignition coils, two motorcycle batteries, a homemade telegraphy key, a spark plug, a simple LC tank circuit and a very long piece of wire to be the antenna. The receivers were just AM receivers tuned to the top of the scale. I gave one of the abominations to a cousin I had living about two miles away. I kept the other one. We both tuned our AM radios to 1610 AM and started tapping away. We could hear the other operator easily two miles away and we had a cheat sheet to tap out the Morse code letters. Unfortunately, those were the days of analogue television that was received over the air with a TV antenna mounted on the house roof. My cousin and I were not the only ones that could hear each other tapping out or butchered Morse code. We tapped out our messages most of the summer. At the end we did not even use the chest sheets. Then one day my father found me tapping away on my spark gap transmitter. I got in major trouble. People all over the neighbourhood were falling victim to my sloppy transmitters on the telephone, television, and radios. After a date with dad's scorn, I had to take my cousins transmitter back. My father made me go get my cousin's transmitter by foot, dismantle it, and carry the heavy, bulky, transmitter parts back and give them to him. It was 90°F so it was not pleasant at all. The two batteries, two coils, excess cable, home made key, and simple tank circuit all weight what felt like about 85 pounds. I guess that was punishment enough. The transmitters was never mentioned again by my parents. I thought they were cool. The neighbourhood did not.
That is absolutely awesome
@@brandonlaragirl I still remember how to make that radio wave mangler. Today, I could probably get away with it since the over the air signal is digital, telephones are digital cordless or digital cellular. The regular analogue radio would still suffer. But streaming radio would be uneffected. But today, I live far away from any family. They reside in a, different continent. I live in a rural area, far from people as well. Even if I knew anybody, It is likely few would want to play telegraph with a 51 year old geezer as well. But I still have memories. It was not appreciated, back then, that when I came to get the transmitter I made for my cousin, he told his father I forced him to take the transmitter and use it.
they had no whimsy in their life
@@cassandradawn780 People have no sense of humour. They could have taken the opportunity to learn Morse Code. They squandered my free service.
@@indridcold8433 well i would but i don't live in the same country as yours 😥
Just so others know, the whip antenna that is extended on top of the portable radio is for FM only, the transmitter he has built is AM and the radio uses a ferrite bar antenna that is located inside the radio. That ferrite bar is very directional.
Yes this is true. there are 2 winding on the bar one with 18 turns the other with 9. the one that has 18 is connected to the field side on the variable capacitor the other is connected to the first IF stage of the AM receiver just before the detector. This is usually a low voltage zener diode.
You always seem to answer something I've been recently thinking about. Just a few days ago I was wondering about radio transmissions, and now here we are with a great video explaining it. Thanks for all the hard work you put into this channel!
Awesome vid. Love the energy, pace, content, and most of all, the thoroughness in explaining and showing your project.
This really does work! I built one this week and it works surprisingly well. The audio quality is pretty good considering it's AM.
Make a class AB amplifier with two Mosfet transistors and make a 100 watt AM station. The schematics and parts are readily available on your local internet.
Actually, there is no intrinsic reason why AM cannot be at least medfi. The problems are mainly limited bandwidth in a crowded band but in your house for a limited range, you can have a pretty wide bandwidth. The other is atmospheric conditions.
This is the best explanation of how AM works. I thought I new AM pretty good ,but this shows how you never know everything. I have never seen such a simple way to make a AM transmitter. Using just a Oscillator and a transformer was great.Keep up the excellent videos and thank you.
+kardeef33317 thank you! :)
I think this was a better quality video. You actually took you time explaining and went in-depth on how it worked. It made it so people like me, who don't really know anything about electronics, could really understand. Nice job!
+Scott Roberts thank you so much! :)
Anytime. Gotta give credit where credit is due. :)
Love your videos, I'm actually learning quite a lot from them! Keep it up!
+Arron Fox thanks, and glad to hear it! :D
Dude u r a rare breed, smart, well presented video and u can draw well! Subscribed!
Nicely explained in a really cool way!
I just saw this video, and it's very informative. I just would like to see a list of the things you need to build it, and a list of places where you might find them. I hope later in the future you might revise this video to show how to wire a bluetooth component to it instead of just an auxiliary port, just to give that much more portability. I myself am wanting to make one to use in my classic car without hacking into my dash. Fantastic video though!
Without a license the legal limit for AM broadcasting is 100 milliwatts, with a maximum antenna length of about 10 feet (this is highlighted in Part 15 as well).
Oh ... how I love the things you do ^^ I wanted to build a device similar to that for a school's project but my teacher couldn't really hook me up with any support and I couldn't find good one either. Also, my knowledge about this area of technology was very limited back then. So I just let it pass. And now months later your video rolls in and shows a good and simple way for building a radio transmitter.
Sorry for this wall of text but I just wanted to share my exitement when I say that you finally tackled this topic! Anyways, keep up the good work ^^
+ˈxames thank you so much!! :D
yasss!! Keystone Science. Yet another great video!
+INFINITE SCIENCE thanks!! :D
I would really realy appreciate it, when you show us a AM reciever the next time :)
Btw this was a really good produced video!
Keep on doing this videos I really enjoy those!
You have now a new sub :)
Yes pls do it.
AM receiver that I made and worked i.imgur.com/S7cw8DJ.png
Pretty amazing video man and its also educational :D Keep up the good work
+John Dante thanks !! :)
Wow...I finally understand how this thing works ! 🎉🎊Thank you very much 👍🏻
Great video - given the limitations of the crystal oscillator and the sub harmonics that transmit onto other bands, is there a way of adding in a RF band pass filter and how would you put one in for the desired frequency?
Hey plz plz plz tell me if it's possible to modulate Fm using same crystal circuit with transformer or any single transistor , i know single transistor fm transmitter circuit exist but that's not stable like this ! Plz share ?
Because i wanna built fix frequency pet or dog tracking device ?
I’ve accidentally ordered a 50mhz oscillator. Now I have to make a 50mhz reciver.
Thanks for making awesome vids!
1:10 - 4 rounded corners & 1 sharp corner...
I'm actually planning to use this transmitter to radio control an engine's throttle in an interesting way. My idea is to transmit a variable square wave to a receiver unit on the motor to vary the torque output of a small electric motor that can pull the throttle open and let it close with a spring. It will have a mechanical safety system so the throttle can't open without someone actually on the vehicle.
3:23 Thanks for your uploads. I like them. One small pointer - that was a slip - the "1000 Mhz"...
Well, I guess he was using a transformer out of a microwave oven😬
Cool idea. Even in place of the transformer, you can include a carbon microphone in the power circuit.
How?
I want to get a clarity on what factors does the range decide and how can I control it's range .pls make a video on it.
Hey man do you even know that you are a genius?? Keep up the good work ....
+Shiladitya Ray haha, I'm not a genius... But thank you!
+Keystone Science hey man is it possible to change the jack to a microphone so i can transmit my voice to a reciever?
@@kelvdean6413 Why not try it and see? You might get away with a very high output capacitance mic as they have an amplifier built in, it MIGHT work with a cap mic series with the 1Mhz osc in place of the transformer, Note that capacitance mics get power for an internal amp down the same wires as the signal, and usually have +ve and -ve polarity for this reason.
OR you could feed the mic into an amplifier and the output of the amp into the transformer where he puts his audio source, the phone.
If you're not sure of yourself just get something working to feed your voice out to a loudspeaker and then swap the transformer primary for the speaker.
5:59 how did you amplify the signal. I am confused as there is only one antenna cable coming out of the transmitter and you had connected two wires. I just would like to ask for an explanation how did you do it.
thease wires go to audio in on the transmitter(one side of the transformer) and the input of the amp goes to the phone
o nice, i absolutely love you, i just needed this next week, thanks a lot dude.
+zxmuffinxz thank you!! :)
Great channel. Keep it up!
What do you think the range would be if you didn't add an antenna? I'm looking to make one for about a 6 foot transmitter so I don't have to buy a new stereo for my car. (it's AM only. real old one.)
Very good video. I learned a lot
Is there a crystal oscillator in the range 160-190KHz?
Popular electronics has a circuit in its January 1972 edition. There is only one drawback is locating the RF oscillator coil. Miller X-5496-C is needed, J C Miller made one for this project but they are almost non existing now. The other coils can be wound. The circuit may have other issues or it may be matching an antenna for this transmitter. Total length is 50 feet or under. Good luck.
what is the voltage on the secondary side of the transformer that will kill this system? got a 25W TDA amplifier having its peak output at any frequency 12V....i got an old ferrite core doorbell transformer (quite a powerfull one) and it steps down 220V to 24V---- i did made and "inverter" with the amplifier so you can use a 240-12V transformer hook 12V 50Hz signal which comes from amplifier creates quite powerfull arc...but where is the limit and what is the sweet spot for this design?
The circuit you shown for a amplifier for the transmitter I would use a negative voltage on the ground for the LM386.
Thanks for sharing friend! Do you have a video for receive?
do you happen to have more detail about the transformer and how to drive it w/o a cell phone?
Sir, the frequency of your speech is about 1 MHZ ! Great Video ! Keep it up.. Love from Singapore...
Thank you very much for this video!
well done
how do we make the thing at 5:30 ? where it says ground what does that mean ? the ground of the audio source or the transmitter ? heres where I get into troubles
Hi. Nate . can plzz say where i can get a oscillator chip because i have not got it
How do you set an specific frequency for broadcasting the signal?
You could buy several crystals and use a switch to switch from one to the other, but this is a very crude circuit - modulating the circuit voltage with audio is terrible. Ideally, you would want a circuit with several transistors, one as a dedicated variable oscillator.
Can someone explain to me how I can use the formula in the video to calculate the right capacitor to use in the receiving circuit. I would appreciate that.
Where can I get a good step up transformer like the one in the video I looked and did not find any
I somehow clicked the notification without it switching to CZcams app, so I had the sound only on my phone and had no Idea where it came from, when listening closely I heard something along the lines of "this is gonna broadcast on frequencies illegal in your country" and I almost thought I was somehow receiving some secret transmission, but then I found where it came from and it was just you :)
+Félix Réfax hahaha xD
great video !! go ahead with such !! we all like it. pls tell me someone : can I use different Crystal value ? if yes, what need to change for this ?
Hey does anyone know where i can find this in greece beceuse its dificult to find that oscilator
Hi! Does the frequency of the oscillator alter the frequency broadcasted? I.e if I use a different 2 MHz oscillator will it broadcast on 2000?
+Max ScurrahRose yep!
So the antenna is everything when it comes to the range of radio transmitters?
If I chance the signal which output from an adruino to audio input, this circuit can operate? I have a project which have to transmit Morse code through AM. So I intend to use adruino to code Morse, then send through your circuit.
did it work for you ? if yes, I would be happy to learn how
@@moshezohar6839 Sorry, I haven't got it. But I used two module Nrf24l01 for transmission information
Can I use a 1:1 ratio transformer?
Great quick video. I connected my transformer to my positive rail and my power inuput at top left. I see a strong spike in SDR UNO. No sound from my phone.
I do hear my phone if I connect the transformer to my positive rail and the antenna pin but the range is like 3 inches from antenna.
Anyone have any thoughts?
i can't find any ocillator with 3 pins... where can i find them?
I love your channel 😀
+Apodis thank you! :D
Well Hell you just Ansered a Question of mine that I was looking for about a Year my question is how do you get rid of the ringing?
Double Thumbs up....very informative.
Can you make a tutorial for transferring electricity within a house to make the light bulbs wireless specially CFL???? if you have already done please give me the link....
Thanks
good stuff man
how do you know what frequency it is transmitting on?
Hi sir, can I ask what is the value of the step up transformer that you used? Hope you would answer my question. Thank you :)
Cool video! I always wondered, how i could build an Am transmitter by my selfe! Thanks!
+Schwarzbildvideos no problem! Thank you! :)
I have already ordered the parts online :)
@@schwarzbildvideos4971 from whom please.
GOOD JOB MAN WHICH YOU THE BEST
+marouen boubaker thanks :D
Could you replace the crystal oscillator with a variable resistor so you could adjust the frequency which is broadcast?
No. For proper transceivers this is called a VFO.
Hello! I totally agree with you - AM transmitter is much easy that FM UHF. But if you want to realy translate your own program on long distance - you need a space for the antenna (2 long wires with length = 1/4 wavelength per one wire) and you should adjust the one in resonance. If your transmitter works on 1600kHz - the length of the antenna (dipole) will be quite long - 125meters.
or use a coil
very nice and simple.
Excellent
Kindly suggest if AM Radio Transmitter KIT is available at a discount of 50℅
Could you scale this up with larger amp and antenna and get longer range
For your next video,would you prove this circuit,it transform radio waves,in dc current?
I'm a big fan,great job ;)
Can i use higher frequency osscillator?
Is there any way of making this with a 2-pin crystal? Here they don't sell 4 pin ones at 1 mhz
Amen.
What is the specification of your transformer? Nice video by the way!
Great video to start the youngen into electronics.
If you ever get the chance, can you show how to make a fox hole radio? It's a radio that was used during WW2 and consisted of a blued razor blade and no power source. Keep up the great work!
Actually i want to build a morse code transmitter so can i use a switch instead of the transformer
what is the VA rating of the transformer? Is there any upgrade to increase the range?
You aren't dealing with any power, so anything will work. This transformer clearly is a standby AC input transformer used to supply 5 or 12 standby volts to a radio or stereo receiver.
If you want a transmitter for long wave radio there are circuits you can build. Popular Electronics had how to build one. The only problem is you may have wind your own coils. The part needed was sold by Lafayette Electronics which went out of business years ago. My friend went.to the trouble to build the project and it worked as far as in his house but the range was short. So he just abandoned the project. Maybe someone has corrected the out of tune problem. That what popular Electronics call the one section for correcting errors on circuits.
Someone help me that how I take the crystal oscillator on Proteus software
Superb
so, a coil would be the best antenna?
Awesome video if you don't mind me asking. The only thing I don't understand is what is the purpose of the transformer? Under normal circumstances I understand how a transformer works and this application I don't get it.
No worries at all! Here, the transformer is only being used to give a boost to the regular electrical signal (when the audio plays through one end, it adds or interferes with the voltage on the other end) so that we get an audio modulated signal on the output
I have an oscillator with only 2 pins..How can I use it for this project ?
That’s a crystal. An oscillator in a can contains the crystal, and a logic buffer to drive it.
what specs does the step up transformer have
very nice!!!
+thank you! شبكة الإبداع والتطوير
Hi how to make a your own 1MHz oscilator using transistors?
What would happen if instead of amplifying the audio signal going into the transformer, you amplified the modulated signal at the output of the crystal oscillator?
Hey! Is that type of radio good for Morse code transmission with a straight key?
If u want you can connect instead of audio source a swich connected to 500Hz signal source and you could then use it for morse.
Can i. Use oscillator 4MHZ?
cool !...... made all kinds of jammer/Xmitter circuits(broadcast TV, AM/FM, vintage cordless house phones & even analog UHF cellular) back in the day......mostly just to F with A-hole neighbors & Guidos blasting disco/rap in their IROC's etc........ was perpetually on the look out for the FCC van / dudes with directional antennas !
+realcygnus hahaha xD
Can i use a 40 MHz crystal oscillator?
You could refine this with a band pass filter on the input. And a low pass filter on the output. So the signal only is heard on 1Mhz and not on 2,3,4,5 MHz etc. 👍🏻
Where were you when I made a couple spark gap transmitters so me and my cousin could tap out Morse code a couple of miles away and listen in a regular AM radio tuned to 1610AM to hear the other. I did not know every television, radio, telephone, CB, cassette deck, 8-Track, within a couple of miles were hearing our butchered Morse code transmissions. I got in a lot of trouble. My cousin did not got in too much trouble because I made the transmitters. Of course he pointed out that I made him take one of the transmitters and operate it.
Indrid Cold probably where I am right now. But spark gap. Isn’t really filter able. That’s why it’s band now.
@@pd1jdw630 It was bad alright, my father sentenced me to one year hard labour. The house and yard never looked better shortly after my home made spark gap transmitter, and my cousin's was confiscated. However, at the end of my sentence, the following year, my father bought md a CB radio. Do you remember those? My uncle also bought a CB radio for my cousin. Of course, the activity on them was supervised because of my spark gap days. He also bought a cheap receiver to listen in on our doings. Those were good times, except for the one year, hard labour, sentence. I do not think CB radios are even marketed anymore. All the department stores had them. My father bought me a JC Penny radio. My cousin got a K-Mart Kraco.
Indrid Cold ooh that’s hard. Little did you know you where transmitting over the complete radio spectrum.
I do remember CB radio. It never drawn me. Cause by the time I was in my teens it was the 90’s and CB wasn’t really popular anymore. However making contact to the other side of the world grasped more my attention. ( reckoning this was before 1994 internet came here )
@@pd1jdw630 Dear old dad did give me some credit for my homemade spark gap transmitter. Before he layed down the law, he said, "Not bad for a 12 year old."
You are right. It was before World Wide Web. Computers all ran Microsoft Basic. IBM-DOS and MS-DOS 2.1 was all there was to operate computers. BASIC was the programming language of choice for homebrew programmers. Cassettes and 8-tracks were the audio media of choice. Oh, and only two genders and American flags were allowed to be flown with no grief.
Thank you sir
+ keystone science could you use that lightning effect to track thunderstorms? Just an interesting thought
+*** *** probably, you would probably need 3 receivers, then just using a formula to calculate where the strike took place based on the small time difference each arrives at the source
Keystone Science you're taking about something like triangulation, right?
+*** *** yep!
Keystone Science cool, nao all I need to do is not be lazy and do the research/get the radios, lol
You should list the pens you use in your description. I saw a Pilot Metropolitan and I think.. an OHTO?
What pen is that? It looks really cool!
Nice Video! 👌🏻
+Marty McFly Thanks marty!
Instead of modulating at the power input of the 1MHz Oscillator unit, could you run the oscillator at full 5VDC, amplify the steady 1MHz output through an LC tank with a MOSFET and series modulate the tank with a 1:1 ratio transformer? Would that produce a stronger and cleaner signal? Perhaps filter out harmonics with a Pi network filter?
I assume this circuit would differ for a simple crystal rather than a packaged crystal oscillator. Could someone describe these changes?
Try neil steiner,k7ns iron pyrite negative resistance oscillator -spark,Bang,pop
hey, I really like all of your videos .now I am trying to do a flintstones tesla coil if you can make a tutorial on how to make a flintstones tesla coil it would be soo helpful. please.
can u show us how to make a ESC ??