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

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.

Parts list: (affiliate links)

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.

[LightningHelix]

Getting boxes to talk to boxes. Coolest stuff on earth

[doge]

Fun fact: this video is not sponsored by JLCPCB.

[DSage]

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

[kermitdaphrogge]

Hi, Bro!
I saw a random guy the other day on YouTube, 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.

[bubbamachina]

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!

[ovalteen]

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.

[DoctorX]

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

[joshm]

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

[pepethefrog]

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

[iqtutorial]

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

[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.

[aphiewbareh]

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

[smeegle]

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

[filipw]

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

[netx]

I know this is very old now by Youtube 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.

[Ayaxia]

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

[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.

[amyshaw]

Its a magic "Summon the FCC" circuit!

[nikims_]

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