AM Radio Transmitter on ESP32 

Is that the recording in the end an ascription to the Hawaii wrong nuclear alarm

You can try making a magnetic loop similar to the loop on your receiver. The magnetic loop can be adjusted using a variable capacitor to allow it to resonate to your carrier. There are many online calculators available. I would also suggest adding an amplifier circuit to drive the loop while keeping the output pin on the transmitter safe. Thus a high impedance input seen from the pin and the gain of the amplifier will help boost the signal to make it propagate further to your granny next door.

I remember AM transistor radio kits i use to play with in the late 90s..It took me 100 times the effort to build one...Thanks for the video

Simply super clever. This is what I've been looking for to give my old radio's some extra life. I have tube radios like yours, big console radios, one of them is from 1949, and this would be nice. I can imagine streaming audio to it, and using that as the transmitter.

You Rickrolled us! :') I am so glad you made this awesome video! Thanks.

This one was really awesome!!! I really like your style and sense of humor!

Love the simplicity of this design and that you used a simple esp32 dac. Your videos are good food. Going to sign up for patrion for you

I know this video is old and I'm sure someone already commented this, but antenna length (without going into crazy details) should generally be 1/4 wave in length for optimal range.

I am in awe. The level of technology here is amazing, you explained some things about AM transmissions is such an easy way to understand. The vintage radio looks like a Grundig? On top of all this, you are a musician. I bet you know how to cook too. ;-) I think all you need now is a 1kw linear amplifier and you can become Radio Bitluni. Keep broadcasting!!

*It is a joy to watch your videos!*

Haha your humour is fantastic :D Also very nice use of the 8bit DUCK

The antenna length for a radio transmitter is generally some multiple of 1/4 wave length. But that's only part of the story, the transmitter's output impedance should match the load impedance of the antenna. This load impedance differs depending on the type of antenna you use. I suspect that if you were to cut a wire the same length as the antenna and attach it to ground, you may get better range. This wire is called a counterpoise and gives the antenna a "ground plane" to radiate from. Or if held inline with the antenna wire, you'd have a dipole, though for a much higher frequency than intended. Also you could add a coil to the bottom of the antenna to add some inductance to it, which makes the antenna appear electrically longer to the transmitter. Good Luck!

This is a really cool weekend project, man! Keep it up

You’re quite an amazing genius. No one else covering audio like this. Original content...because genius :)

I think antennas can be 1/2 or even 1/4 of the recommended length. Also, coiling the wire if it is long can help manage these potentially long antenna wires. Various modern antenna designs can do amazing things with short wires. The problem is they are not free. Nice project I just subscribed as you appear to have some unique projects/ideas I'd like to explore.

This is a kiss from love of technology 😘Mmmmmmmmmaaaahhh, well done my dear luni, your work have won my heart

Damn I have a lot to learn on this but videos like this are quite an inspiration.

4:49 not sure if you've discovered it by now but an "ideal" antenna length for transmitting/receiving is either a 1/4 wavelength vertical using a ground plane (like on a car hood, the car body is ground) or a dipole antenna with two 1/4 wave elements that alternate +/- fields, like on old TV's that used "rabbit ears".

I just tried this and it works great. It's brilliant in it's simple implementation. Congratulations. The only issue I had was the I2S_NUM_0 is the DAC1 pin not GPIO_0, missed that point in the video. Once that was figured out, I received my wav file on 835Khz.

Amazing trick and nice video editing. Your videos spark my interests.

Amazing work.Congratulations

Congratulations for the video! Your videos teach and make me laugh a lot too!

Good job!!! Thanks for sharing, Bruno!

Great project, I love the Hawaiian touch at the end.

High Five! I've got this project running, on the same 5" B/W video monitor that I run your first composite projects on, because it also have an AM receiver and FM receiver.

Always Genius,i admire your creativity

Awesome job! It reminds me of the numbers station project for the pi

another great little project.

ROFL enrick!!!! that got me on the floor. Usually antennas are 1/4 wave length. been 30 years since I had worked on it at a technical college.

Awesome work - thank you!

That's pretty awesome, you should buy a cheap wideband RF amplifier (you can get miniaturised ones from eBay and such, also they run on 5V), then link it up and see what the range is like afterwards.

the antenna type that you want is a monopole antena, that type require a length of 1\4 wavelength, but that requires a counterpoise to work properly. also an antenna do not works just by length, tha shape and position takes a good part of the data to characterize an antenna, also your transmitter do not have a constant output impedance so a precisely shaped antenna will be worthless. in this case coil up as much wire as you can and you will be fine :) manuel, 18 years old ham radio operator from italy

Best antennas for MW band are ferrite based, those are lossy too. In order to improve the range a band pass amplifier is mandatory along with such antennas

Fantastic yet again.

Great work!

great project. i will be doing this today

Hello Ah! old amateur radio memories come back to life! (I hope not to say nonsense: I go to memory 20 years ago) for good signal transmission there are at least three very important variables: the power of the transmitter (I think ESP32 does not have much to put out) The length of the antenna (based on frequency and wire propagation factor) The relative position between the two antennas, (RX and TX) the higher the frequency the higher the influence of relative positioning of the antennas is. In your case, given the frequency and the distance between TX and RX, I believe that the main responsible for signal attenuation is the microscopic output power of the ESP32. The antenna of the modern tuner is then of the ring type, so as it is done it should not be affected by the position of the transmitting antenna and is calculated to pick up microvolt so even the small power of ESP32 is captured, a short distance away, but as soon as you move away. .. The power drops with the square of the distance, so ... You could use the output signal to excite a linear amplifier (for these frequencies: a simple amplifier with a normal transistor and a band-pass filter, you can find amateur schemes on the internet) adjusted for the AM frequency and drastically improve the range of your ESP32 . for some proof it can be done, but I do not know the German laws and I would not give you problems of transmission nonn authorized, of these times I would not want someone to accuse you of acts of terrorism :-) P.S. in case you could think of making yourself a long antenna do not do it in full wave, but at most 5/8 wave. if I remember well, You do not get a good signal transfer.

It was back in 1977, I was just completing my 2nd enlistment in the US Army, since I was going to get out, the recruiting station where I was located put me on terminal leave, so with nothing to do, I enrolled in college studying to be an auto mechanic. I was a bit of a older student at the time, and it happened that one of my fellow students had rolled his muscle car by driving a bit over the speed limit, (read about twice the limit) so he was without a ride to college. I drove right through his town to go to the Tech every day, so stopped and picked him up to give him a ride. I was driving a little Opel Manta, neat little car, and my experience as a police officer gave me a bit more skill to drive those wandering back roads of rural Minnesota. The little bastard used to brag all the way to college and back about his driving skills, so I began getting even with him. First, I would drive, a bit over the speed limit when I came to where I knew he had wrecked his car, then I began getting closer and closer to the guard rails that protected us from the narrow bridge crossings on the back roads, and last but not least, I found an 8 track tape (after in 77 what else could you play in a car?) with police sirens, So when I neared that bridge, I floored the little German car, she jumped forward like a spurred stallion, up across that old wooden bridge, the door handles nearly scraping the guard rails, I pushed in the tape and told him to hang on, the Sheriff is behind us. He ducked down and began to weep, so being the kind hearted man that I am, I only kept up the fake chase for another mile or so before announcing that I lost the cop. Result? The dude never again asked me for a ride to college.

Funny way to learn something. Thx for this.

The Rick-Roll was simply outstanding! Subscribed!

You videos are great...

Hey mein bester, hammer videos und ein mega geiler Kanal!!!! Bin ein riesen Fan!!!!! Mach bitte immer weiter so. Viele Grüße Michi

Your electronics room tho, so clean, SUBBED!!!...my "project" room looks like someone shot off a cannon filled with components -_-

Funny and Simple.. good video!

This video is a classic. Makes me spit my coffee out laughing every time.

DUDE YOU ARE AWESOME!

Nice!

THIS IS SOO COOL!

Ingenious

You're a genius !

Awsome!

brilliant video.. your a cleaver fella :)

Nice one! thank you

Im your fan!!!!

This is sooo funny and impressive. :)

Nice idea

The younger generation will never know the joy of rick rolling someone *one tear runs down my face*

I was just wondering the audio you used for the esp32 “This is an emergency broad cast. Nuclear missile inbound detected…” Where did you get that from? Thanks.

You are the best

Excellent

my dude its all good your radio is beast. But I will suggest a trick I discovered that works most times. Take a antenna from a car and just stick a jack to it works wonders xD

I too do not have much knowledge about antenas, but in my university(UFCG), people use this book as a reference of the class that studies it: from Constantine A. Balanis, Antenna Theory: Analysis and Design. I think you can start with that... Great video! If you want some help to find the book, comment below... :)

Would this work on an arduino uno r3?

I must've missed the trick, but how AM modulation was done? Do you calculate whole Ampl(t) * Sine(wt) and send it to the DAC in real-time?

Hi, great video, fantastically simple yet so powerful. Have you set up a transmitter / receiver pair?

In the US, the FCC has rules about the size of AM broadcast band antennas used with unlicensed transmitters. I think it's like 1 meter long or something. As far as practical small antennas for medium wave, I'd suggest multiturn loop antennas.

Love the quick jokes!

Have you tried hooking up a standard AM loop antenna like you have on your receiver?

Masterpiece (y)

do you think that a esp32 would be capable to decode a component or s-video signal and convert to vga? like a video adapter?

Is it possible to use an Analog input pin for audio in? I'm not confirm to audio signals on an 3,5 mm jack but may the voltage drop on a resistor could be used as input signal

How do you create the file ? what happens to the audio when you convert it

IIRC the theory... you always want the best aerial on the transmitter and then it matters less what aerial you have on the receiver. This is to do with getting your desired signal further above the 'noise floor'. So maybe borrow the AM loop seen at 2.53 for the TX and use the wire (or a ferrite out of a junk AM boombox) for the receiver. Might also be possible to tune the loop (which is inductive ofc) using a variable cap across the twisted pair feeder.

Does this have to be modified in order to work on the ESP8266 12E?

how does your converter work? I would like to replicate and modify it for a project of mine. I am trying to wirelessly add the file to my ESP32 using OTA.

1/4 wavelength wave is best. Load with an inductor (coil) in series for a shorter physical antenna.

The code after the "//modulating that sample on the 16 values of the carrier wave (respect to I2S byte order, 16Bit/Sample)" comment, why do you have to increment with 0x8000? I suspect this is to keep the MSB a 1 but why?

Which pin should the antenna be plugged into for the ESP32 MiniKIT?

Awesome! Any luck with FM transmissions?

Can the frequency be changed? This is cool as heck but I don't understand the math behind it :/

Could this be used for a FM transmiter for use as Ham radio Fox hunt transmiter? would make it nice and small and hard to find.

i just found yur channel.yur awesome..is it also possible to build an FM transmitter with esp32? can we boost the signal strength with an opamp? does the the esp12e have any DACs?

Did you use a DDS technique for tuning?

Very nice! Been looking for a home Hi-Fi AM transmitter to broadcast oldies music to my tube radios (one of which is a Grundig Type 2030 W/3D radio from 1955 that looks strikingly like the nameless one you have in your video). I'm especially interested in getting bandwidth as close to 15 kHz as possible to reproduce the best Hi-Fi AM sound, which is what those old radios used to receive before FM became popular in the 1960s. Today 10 kHz BW is the legal limit for AM but as long as no commercial stations are nearby, exceeding that by a few kHz in a very localized area should theoretically be possible. By localized I mean keeping your signal under 1/4 watt so your range will barely make it out your front door.

Well done! I think you can get better transmission adding a unity gain op amp, since the DAC is really low power

you are best

very nice :)

Or you can attach a 225 meter vertical wire 😵 which is a 5/8 wavelength antenna at 833 kHz.

Hi. I want to build a system like rfid uhf for access control vehicles. Any idea 💡?

04:18 frequency stability seems to be an issue? any fix for that?

You can add a push pull amplifier to increase the output power.

Super! I go to make it.

Пять балоффф... Поучительно и с юмором.... :)

Exelente!

Put a coil in series with the antenna (at the ESP32 end) to match it better to the pin's output impedance and to lengthen the antenna electrically.

This is the second sdr project by you on esp32

Very interesting work. But unfortunately I don't have the right libary's in my arduino IDE. Can you tell me wich libaries I need?

Great !!!!

8-bit Ducks! Excellent!

Is it also possible to transfer video? Like DVB-T?