Building a Super Simple AM Radio Transmitter & Receiver! Keeping Wireless Audio Communication easy!

Check out KiwiCo.com/GreatScott for 50% off your first month of ANY crate!
WARNING: Always check your local law if you want to transmit something with AM! Sending on certain frequencies and thus blocking other licensed transmitters can be illegal. So if you want to try it then make sure that the transmission power is super low. In my example the transmitter was only capable of sending over a distance of around 2-3m.
Previous video: • You can draw circuits!...
Walkie-Talkie nRF24 video: • Make your own very cru...
Walkie-Talkie RF Modules: • Creating a Walkie-Talk...
555 Timer video: • Electronic Basics #26:...
Voice-over Microphone video: • Voice-over Microphone ...
Oscillator video: • Electronic Basics #17:...
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Twitter: / greatscottlab
Support me for more videos: www.patreon.com/GreatScott?ty=h
More project information (pictures,.....) on Instructables: www.instructables.com/Simple-...
Parts list: (affiliate links)
555 Timer: s.click.aliexpress.com/e/_dTr...
Resistors: s.click.aliexpress.com/e/_dTP...
Capacitors: s.click.aliexpress.com/e/_dU4...
NE5532 OpAmp: s.click.aliexpress.com/e/_9JNpe3
Electret Mic: s.click.aliexpress.com/e/_AAJ0er
Perfboard: s.click.aliexpress.com/e/_AZXOgT
PCB Terminal: s.click.aliexpress.com/e/_dYb...
XR2206 Function Generator: s.click.aliexpress.com/e/_Abhz51
TA7642 IC: s.click.aliexpress.com/e/_Adpjwb
100pF variable capacitor: s.click.aliexpress.com/e/_An8vVt
Enamelled copper wire: s.click.aliexpress.com/e/_9i1Heb
In this project we will keep it simple when it comes to wireless audio communication. Instead of trying to use an nRF24 or RF modules, we will go back to the old days in which they used AM radios. I will show you how such amplitude modulation works and along the way show you how to build a super simple AM transmitter and receiver. Let's get started!
Thanks to KiWiCo for sponsoring this video.
Music:
2011 Lookalike by Bartlebeats
0:00 "Complicated" Wireless Audio
0:45 Simple AM Radio Solution
1:59 Intro
2:09 Theory AM
3:19 Transmitter AM 555 Timer (sounds terrible)
6:08 Transmitter AM XR2206 IC (sounds decent)
7:25 Receiver AM TA7642
9:53 KiWiCo Sponsor

[@BlankBrain]

When I was in high school, I worked in an engineering lab. One of the engineers sometimes liked to listen to country music. Another engineer didn't want to hear it. He stuck an antenna wire on an RF signal generator, tuned it to the radio station frequency, and slowly turned up the amplitude. This was done stealthily, of course, so the other engineer had no suspicion. The music just faded away.

[@mehmedcanozkan3268]

“Honey, why does the country music stop whenever we drive by the engineering annex” XD

[@lavakumar5944]

Strictly not legal to jam a frequency but its a lab so one cares

[@hadibq]

haha I would notice something odd's going on that would trigger my need for investigations 😅 unless it jams the whole fm range

[@BlankBrain]

@@hadibq It just faded out and back in like atmospheric conditions. This was AM radio, so a strong carrier overwhelmed the detector.

[@dang48]

@@lavakumar5944 Exactly and of course, when this is discovered by the first engineer, payback can be a real b****!

[@LightningHelix101]

Getting boxes to talk to boxes. Coolest stuff on earth

[@doge5603]

Fun fact: this video is not sponsored by JLCPCB.

[@aadhikarianish]

😆

[@istanbul9189]

Uh ok

[@ukaszKuki]

Faktycznie :D

[@foxinrot]

Nooooooooooooo!

[@RoboIoT]

Then u are a regular viewer like me

[@3DSage]

1:39 That's my 3D printed radio video!! :) Thank you for sharing.

[@TristanYT1]

Oh great

[@dreamlifter7569]

Nice

[@ovalteen4404]

The "easiest" AM transmitter would be to feed both the oscillator and the audio through capacitors, connect the output of both capacitors together, and send it through a common-collector amplifier with no bias voltage on the base. The effect is a carrier signal that changes amplitude based on the audio strength.

[@tafsirnahian669]

A project that I can afford! Great!

[@greatscottlab]

Enjoy!

[@kermitdaphrogge525]

Hi, Bro! I saw a random guy the other day on KZbin, and his process is intuitive. 1. He hand-sketched on the board. 2. Made appropriate drills. 3. Then he laid very very thin wire along his sketch. Then, he put that whole PCB carefully on a surface which he can increase the temperature (he used an iron box). Gradually as temperature increased, wires began to melt and the wiring thing was done. That was cool.

[@joshm264]

I'm glad you posted this, because i want to create one for my tube radios

[@greatscottlab]

You're welcome :-)

[@Ayaxia]

More analog circuits, please! Thank you for your work :)

[@StevePietras]

This was a VERY fun video. and I learned about a kit vendor I never knew about, kiwiCo. Thank you!

[@steel-r_ua]

That was WERY interesting. Thank you for taking time to investigate and record this!!!

[@pepethefrog7193]

Your unmodulated AM signal should only be 1/2 of max amplitude, or 1/4 of max power. Much better sound quality !

[@greatscottlab]

Thanks for the tip :-)

[@johnrubensaragi4125]

Thank you Pepe the Frog

[@fozy6557]

why this man is posting his link in every comment of great scott किन हह

[@fozy6557]

@@projectnepal8482 why this man is posting in every comment किनभने Which city are you from post me

[@DoctorX17]

I'm glad we're going from STEM to STEAM, arts are important and can be a great part of science!

[@jamess1787]

The addition of this vowel will certainly minimize the number of possible candidates.... Not widen it 🤣. Just like how adding science to arts does the same thing.

[@DoctorX17]

@@jamess1787 what do you mean "minimize candidates"? The more the movement covers, the more interested parties there can be involved. It's not like a person is forced to do anything in particular with a program, it's just about encouraging and fostering learning and skills

[@Yinte_Klop_Blunt666]

I'll use this for my thesis next year, thanks Scott

[@69iqtutorial]

Will you be posting more videos for the "trying circuits i found on the internet " series?

[@greatscottlab]

Yep, there will be more episodes.

[@I_killed_that_beard_guy]

@@greatscottlab Thanks

[@MitsuZer0G]

Oh yeah, please! 😍 I'm looking forward to it!

[@koppo5657]

@@greatscottlab speaking of wireless communication. Try making a tv transmitter

[@RegiPavan]

👍❤❤

[@aphiewbareh9466]

wireless technology is always cool, can't wait when Great Scott will soon build up a remote control circuit with just a basic components locally available without a complex IC. and i always dream about it

[@1900OP]

Stop dreaming, start doing.

[@1rbeaucha]

I really enjoy watching your presentations, thank you

[@randomleinadz8883]

Nice work again.. i have learn a lot in your videos.. please keep them coming

[@inventionist172]

Just in time i was looking on how to make these and you have gave an amazing explaination

[@kedarprabhudessai]

Everyone is proud of Great scott !!

[@filipw8073]

Thank you so much for this video, i built 4 fm transmitters earlier and non of them were working, now i built this ne555 am transmitter and it works!! It sounds bad as hell but at least ive got something. Thank you again

[@hadireg]

fell in love with your boombox!!

[@amyshaw893]

Its a magic "Summon the FCC" circuit!

[@rsedivy2]

Well, he's in Germany, and HAM licenses there are called "Amateurfunk Prüfung", so I'm sure he'll be fine. I'm sure he's got enough funk to pass it.

[@jeffm2787]

Not at all. Not enough power to attract attention even if he lived in the US. Yes I have a HAM license.

[@mattsadventureswithart5764]

Nein. Night von Deutschland.

[@bobbysamuels1308]

I'll take a look at this video later, but lemme say thank you so much for brinign back life into such an old topic. Back in school in 2016 i successfully but an AM transmitter only using 2n3904 Transistors (Hartley Oscillator), and i wanted to build the receiver to go along with it, but none of my receivers ever worked. I've tried SO many configurations without "cheating" or using too complext ics, i wanted it to be a receiver using NPN transistors too, but the main issue is idk how to properly measure or deduce why my circuits never worked. Wanna say thanks again, i feel like there's hope for my project again. If yall are interested i can get the schematic of the transimtter that worked at lest. Thanks @GreatScott!

[@Kevin-jz9bg]

hey i had the same issue, it's real frustrating maybe try this circuit www.talkingelectronics.com/projects/TheTransistorAmplifier/images/Fig71bd.gif you don't need the transformer, just connecting the speaker from 3v to the collector of the last npn transistor works fine. And make sure to put >22uF decoupling capacitor across the supply so there's no unwanted noise. 2n3904 and 2n3906 transistors have worked fine for me. Only problem is that the output sound is really small. Maybe you can replace the speaker with like a low value resistor and then add a class A amp after the last stage. (don't tinker with the other stages, doesn't make the sound louder, i tried yesterday) hope it helps :)

[@bobbysamuels1308]

​@@Kevin-jz9bg Thank you for the reply! it REALLY means alot to hear that there are others that tinker/deal with this kinda stuff given im a noob. I'll definitely test this. Here is the transimtter i used to build it. Its based on a radio project from a RadioShack 300 projects in 1 kit. I took their morse code transmitter and added my computer speaker input into it. i broke it up into 3 stages because it was easier to draw lol. bubbamachina.files.wordpress.com/2018/04/am-transmitterpng.png?w=666&h=1024

[@Kevin-jz9bg]

@@bobbysamuels1308 thanks for sharing!! I'll try to build it and let u know how it goes!! For the inductor in the hartley oscillator, can I just take an am inductor from my am radio and tap the center? (it's 55 turns on 1cm * 10cm ferrite rod) I'm a total n00b too but hey "it's super cool, which I think should be the only prerequisite for doing science." - Physics girl U shud check out talkingelectronics.com for a buttload more of projects :) i recommend buying some generals purpose npns and pnps in BULK and just building whatever seems interesting: www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P2.html?ref=driverlayer.com

[@VolpeInCalze]

I had to do a report on AM in our communications class. Built the same transmitter with the 555 and paired another 555 to send a square wave into the transmitter (pretty much broadcast a tone over AM) it blew everyone's mind in class. Teacher was amazed haha. Also, they have crystal oscillators for am. Litterally plug an audio source to it, make an antenna and you're good to go.

[@mohinderkaur6671]

Make an Antenna! thats what I have been trying for the last 30 years!

[@ahmedelmazaty9459]

Thank you. Yes make these kinds of videos that is simple and easy to do and videos about electronic basics

[@labiadh_chokri]

Nice video , that single ic remembered me of its grandmother the zn414 from the seventies.

[@das_lalle2472]

Great video..! Now I can test my old vacuum tube radios if they can still recieve sound!

[@anindyadas6482]

Cool project and very informative for Electronics students

[@akashpathave8985]

I Really Love your videos, There more knoledgable than my 4 years Engineering Degree ...

[@anmolkumar6704]

I got a simple project that i can built this week, thanks :)

[@greatscottlab]

Have fun!

[@3v068]

THIS IS THE VIDEO I HAVE BEEN WAITING FOR!!!!!!! THANK YOU SCOTT!!!!!!!!!!!!!!!!!!!!

[@greatscottlab]

You're welcome😁

[@RickB3n]

Great Work! Greetings from 🇮🇹

[@I_killed_that_beard_guy]

??

[@Gamezone-sd3er]

Finally I can build this and give it to my dad ❤️😍🤗 thanks 😊 great Scott

[@greatscottlab]

Hope you enjoy it!

[@smeegle]

I've been looking at making something like this for the past week! Amazing timing

[@greatscottlab]

Perfect!

[@RoboIoT]

Hello sir. I am a 13 yrs old electronics enthusiasts and I need some help. Can I contact you. I don't think so bcoz I think he would be busy.

[@zrxav]

@@greatscottlab Hallo, greetings from Venezuela. Thank you very much for your videos they're so cool and helpful! I've been researching a little bit about IC that could function as a replacement for the TA7642 of your AM RX and I found out this two ICs the TA7640 and the TA7641, would you recommend either one of them to be used in place of the TA7642? Thank you very much for your time and help on the matter, I really wish you're having an excellent day! Tschüss! :)

[@danielmendes5682]

thats the exact project i was looking for! thank you so much :)

[@greatscottlab]

Glad I could help!

[@ravindrabhoi8944]

I think I'm on right channel thanks Scott for great videos

[@AhmedAli-qd1hu]

Dude Just awesome experiment ❤️❤️❤️😍 Keep going

[@jrioublanc]

Nice, sounds like very old voice records. :) I like this video.

[@Tx_6969]

Thank you so much for this sir! I'm gonna try! 👍👍👍👍👍👍

[@utku6655]

This was my capstone project!

[@RC-Heli835]

Great job GreatScott! I'm trying to learn how an rf transmitter and receiver functions so that I can understand better how to trouble shoot them.

[@ZaneDaMagicPufferDragon]

AM ALL THE WAY!!! Awesome video and very informative about how Amplitude Modulation works and how to make an example circuit!!! Thanks for another extremely educational opportunity for learning more about RADIO 📻!!!

[@greatscottlab]

😁👍

[@MarkSeve]

Awesome, now to take it to the next level.

[@priyasiva2100]

Cool man I can use this project this is very useful. I can support you.

[@MCsCreations]

Fantastic work, dude! Pretty interesting circuits indeed! 😃 Stay safe and creative there! 🖖😊

[@greatscottlab]

Thanks, you too!

[@JawadAhmadsahibzada]

Great 👍🏼 Scott !!! Love it

[@netx421]

I know this is very old now by KZbin standards, but i built a similar deal as this with a car battery and a 1k pot, a 100uF cap and a 10k pot . it works very well and my sdr picks it up all over the dial. you leave the 10k pot at full and tune the 1k pot to the desired frequency. I ordered the circuit you suggested anyway and cant wait to start using it instead.

[@nikims_]

Amazing! Finally a project I can build without much hassle ;)

[@bat4]

We've got you surrounded! Come get an HF band license ~ Federal Communications Commission

[@nikims_]

@@bat4 I WILL NOT GET A CLASS 1 HAM RADIO LICENSE I WILL NOT GET A CLASS 1 HAM RADIO LICENSE

[@serignebah4788]

Did you watch the whole vid already

[@nikims_]

@@serignebah4788 i watched it 4 days ago

[@serignebah4788]

Perhaps that will be from ZouTube not youtube

[@joeybonin7691]

I like simple. I used a 6888 vacuum tube, a tank circuit, and a TTL oscillator, with a triode to drive the screen grid. Works great. I get about 5 watts of RF.

[@enricoboldrini5350]

I know I'm a bit late, but do you still have the schematics for your circuit?

[@treytonkibbee5535]

High quality video as always!

[@greatscottlab]

Glad you think so!

[@kenmore01]

Actually, running that 555 output into a tank circuit (probably with a buffer amp) to make it resemble a sine wave and modulating the power supply voltage with the audio would work pretty well.

[@HDXFH]

Nice little boombox Panasonic Ambience stereo is a very nice feature for their boomboxes

[@electrorush7754]

I find your channel and learn many things about electronics and when you explain the circuit by drawing it makes easier to understand. Thanks.

[@frequencywatchers]

Im So Jelous Of Your Knowledge !

[@antexterminator9373]

I remember once years ago I built some type of radio/microwave receiver. It consisted of three quadruple bowtie antennas tuned for around 2GHz and three germanium diodes to rectify the received energy to a signal. I then connected that to two integrated circuits operational amplifiers LM358 (cascading operational amplifier with 22KHz bandwidth) if I remember correct. And that was supplied by a bipolar voltage of +/- 1.5v. 2 batteries. The aim of that receiver was to receive any kind of radio and long microwaves. And it did work. I could catch FM signals, mains 50Hz distortions and the microwaves from the wifi. It was heard like ticks in my soviet era 150 ohm headphone. The receiver contained NO coil.

[@easyelectronics4364]

Another awesome video 🤩🤩🤩🤩🔥🔥🔥

[@josiahantoniogabiano8494]

I'm waiting for this

[@pasindudeemantha8343]

Nice project ❤️😊

[@xDR1TeK]

RF circuits are absolute fun.

[@MultiWirth]

would´ve been cool to build an actual oscillator based on discrete components instead of using an timer IC ;) Back then, there were no ICs inside tube radios 😁

[@brankotdk]

My first am transmitter had only one transistor and worked fine!

[@MultiWirth]

@@brankotdk I´ve seen AM receiver which had no active electronic components at all. Only a coil, few capacitors and resistors and a crystal earphone.

[@brankotdk]

@@MultiWirth sorry for my English... That was probably detector recever. Works without battery. You need also diode (I used germanium diode).

[@MultiWirth]

@@brankotdk it was a "rocket radio" from the ealry 60's. It was a crystal radio (the crystal in this case was the earphone itself) which actually works like a diode but can only pass a very low current as far as i know. Radios from the 30's worked similar, but had a amplifier tube and and speaker. And of course no 555 timer IC 🤣

[@mohinderkaur6671]

@@MultiWirth the titanic reciever

[@jercos]

AM is also a fun way to mess with ultrasonics... if you have a 96kHz sampling PC sound card, it can directly output ~30-40kHz narrowband signals to drive a low-cost ultrasonic emitter. The low frequency compared to RF makes a demodulator circuit simple. This even works with no circuitry in the transmitter at all, some early TV remotes used an ultrasonic tuning fork struck by a hammer to send button presses without batteries.

[@DrHouse-zs9eb]

Very cool sponsor this time!

[@anandhavishnur4689]

Good project

[@DrJALAGHARI]

Thanks for sharing such a nice information.

[@greatscottlab]

My pleasure

[@dinshithd515]

Nice video. I really enjoyed this video. My suggestion is to use wegstr pcb milling machine to get a very nice circuit within less time.

[@Mr.bonbon441]

in xr2206 your voice sound similar to those 80s 90s morning news ..haha so nostalgic

[@Bianchi77]

Nice video, thanks :)

[@shashankarmy]

Straight and simple

[@user_00759]

Awesome!!! Love it. 💗💗🙏

[@HobbyBroadcaster]

Enjoyed video regarding the transmitter build. It's probable that your circuit likely complies with Part 15.209 if you need to keep the radio relatively close to the transmitter. Your video will certainly be of interest to the would-be Part 15 broadcast enthusiast who wants to build their own transmitter before graduating to one of the more costly, high performance Part 15 AM transmitters. Thanks for sharing.

[@Bhavesh_g20]

I think so I am late But here marking my attendance And enjoying the video Hope to get some deep soviet codes via this signal lol🤣

[@markashinhust3428]

Thank you for taking the time and really explaining everything. What pens were you using when drawing your schematics?

[@Mr.Engine993]

I have the same ones, they're Stabilo point 88 fine 0.4 pens

[@electronic7979]

Very good

[@andymouse]

Very cool !....cheers.

[@furonwarrior]

Install a coax cable with a sma connector so you can improve the antenna.

[@DhananjayKumar-uf5ob]

I love this project sir

[@greatscottlab]

Awesome :-)

[@sandeepsahanicodes]

Amazing !

[@akhurash]

Cool project!

[@greatscottlab]

Thanks😁

[@TECHiHOBBYIST]

What how four day ago?..?

[@I_killed_that_beard_guy]

@@TECHiHOBBYIST don't know

[@akhurash]

@@TECHiHOBBYIST Patreon.

[@eyobed5274]

i think its an overkill to use ICs for AM communication. it can be done with a few transistors with great quality

[@rahimkvayath]

thank you for uploading such useful video, by the way , a question what is the model no of that beautiful panasonic

[@ejonesss]

you can also use a crystal oscillator used for microprocessor clocks in the 80s to make a transmitter as it contains the entire oscillator. also as more and more of the analog fm broadcasters go digital there will be the space opening up and the fcc may soon care less about the part 15 rules unless your transmitter should somehow cause a pacemaker to malfunction and cause a heart attack or completely drown out emergency responder communications.

[@zrxav]

Hallo ​ @GreatScott! , greetings from Venezuela. Thank you very much for your videos they're so cool and helpful! I've been researching a little bit about IC that could function as a replacement for the TA7642 of your AM RX and I found out this two ICs the TA7640 and the TA7641, would you recommend either one of them to be used in place of the TA7642? Thank you very much for your time and help on the matter, I really wish you're having an excellent day! Tschüss! :)

[@patstine2741]

That moment when messing with the knob actually sounds good 5:35

[@tonywright8294]

To much information 😂

[@MRHBKJK]

Nice... Thank You.

[@govindsahota6043]

Love from India❤️

[@kaushalsuvarna1284]

Ofc we enjoyed ❤️👍☺️

[@wafiullah-shafia]

Good design

[@wendellporter4875]

i have built am and fm radio transmitters along with rf amplifiers for both using tubes

[@ThePeanutChicken]

Damn this was literally my final project for a lab class a week ago lol

[@navidmafi]

Amazing video as always , will you try FM transmitters too? Thanks again , i learned a lot

[@greatscottlab]

I will see what I can do ;-)

[@navidmafi]

@@greatscottlab Thank you!

[@noahsmith946]

This is a great channel and I say this with love: you should try editing out your inhale after every sentence

[@vigneshr8962]

realy good project

[@greatscottlab]

Thanks :-)

[@avinashranjan9197]

Yes this is the project that can i really make and want to make thanks

[@greatscottlab]

Brilliant :-)

[@ivancapan5345]

At last! Project with which I can test old AM radios in pre-WWII era, or small AM transistors which are so simple they don't have a FM receiver!

[@albertodecaro5290]

Can you, please, show us how to make a better am transmitter; Nice reciver btw.

[@serignebah4788]

Greatscott! The genius.

[@hemmethemma8081]

An AM powerstage would be an interesting video to feed the antenna. 😁

[@mohinderkaur6671]

Antenna coil using a coil form made from a business card- use a small piece of hookup wire between the former and the ferrite rod to space it so that it can be moved for tuning. 1 transistor colpitts oscillator + modulation into the base. 1 transistor reciever... into an earpiece using another ferrite rod coil on former with fixed capacitor. maybe a movable tickler feedback winding to cause regeneration

[@power-max]

5:12 You could probably get away with frequency modulation with the 555 and the radio if you added a high Q LC series resonant circuit to the 555 in series with a proper length tuned antenna. The resonator resonates when the 555 drives it near resonance but increases in impedance as it drifts away. Duty cycle modulation would also work as it a duty cycle further from 50% will have less power in the fundamental and more power in the harmonics that get filtered out.