Super Simple Breadboard-SDR Receiver from 50 kHz to 30 MHz

[@johnford7847]

Very interesting. Thanks for sharing.

[@cemmgrgn]

It was a very useful video, I will design and print this PCB as soon as possible. By the way, greetings from Turkey.

[@commradio4215]

Dear Dr.V. This was an excellent presentation. You condensed scores of articles into a clear, concise, explanation (with excellent real-time graphics.)

[@fjs1111]

I've heard of other quadrature detectors similar in operation, but this is very interesting. SDR is quite fun indeed, thank you for your awesome videos

[@gammaleader96]

The two peaks slightly apart might be an RTTY signal. The german weather service has a few frequencies they transmit RTTY signals at.

[@ifzq0]

Simply awesome. Your didatics are also very good! Thanks!

[@darrellhagan6124]

Very interesting and informative, thank you!. A few years ago, I experimented with something similar - a homemade Tayloe detector, soundcard, etc. and made a rudimentary SDR receiver. HDSDR was the software for it. Although that was a very good learning experience, I quickly began to see that my little receiver had many shortcomings to correct before it could become an actually useful piece of equipment and that I was reinventing the wheel. And so I set it aside and bought an SDRPlay RSPdx receiver. But I wouldn't trade that time and effort for anything else because it gave me a much better understanding of how these things function :).

[@cocusar]

Cool! I bet having a better filter at the input (per ranges of frequencies) and some RF preamps would make this an excellent receiver.

[@pomo7496]

前置滤波器、放大器会增加非线性干扰。

[@coffeecuppepsi]

For Morse, you can look at the audio in some sort of audio editing software, then it's easy to see the dots and dashes and decode it manually

[@DoctorVolt]

Maybe this can also be made by some software in realtime...

[@danpedersen55]

There's also apps for smartphones that decode morse.

[@shoopdawhoop]

This double signal is most likely RTTY of some type. You can observe and decode/encode a multitude of modes (including Morse) using a shareware copy of MULTIPSK.

[@DoctorVolt]

thx

[@daomingjin]

or you can use FLDIGI....

[@eric2x478]

Nice project 👌 keep up

[@julias-shed]

That explanation was really clear many’s thanks for sharing 😀

[@wrekced]

Some of those signals are either fax, slow-scan tv, or other data. You can find out by looking up the transmission types allocated to that frequency. You can get programs to decode a lot of that.

[@DoctorVolt]

Yes, I already did so in the following video: kzbin.info/www/bejne/pIKYlmWQaNOMqdE

[@canoespirit]

The first CW station gave a signal report of 599 (5NN) followed by 'thank you' (TU).Tthe other station then replied with an italian callsign IX1... something (could not read it completely because you where talking over it)

[@larspregge6420]

For the ADC, the samplerate must be more than twice the signalrate, say nyquist.

[@co9681]

Nyquist Shannon sampling theorem states that it’s what is needed to make a perfect representation of the sampled data.

[@temyraverdana6421]

Amazing. Thanks a lot

[@alexengineering3754]

Nice! I want to build somthing similar myself but had some problems with the IQ mixing. Also im not sure if i just make the baseband analog and feed it to my pc, since it has more processing power and a 16bit soundcard. Also the soundcard can be used with almost all SDR tools without additional drivers. Anyway thank you for the inspiration if my concept fails i try it your way.

[@PurvanshuBokade]

Hello Dr volt, i was able to gather all the parts for the SDR reciver except for capacitors of correct values. I really need your help, is there any way to make this circuits with different values of capacitors? If yes then can you tell me how? I am still a beginner. Thanks you Dr Volt.

[@DoctorVolt]

The capacitors used in the circuit have very common values, and every supplier sells them. Best buy a good assortment of ceramic capacitors, there you will find them, too.

[@vanhetgoor]

There are many different modulations for radio broadcasts, when the waterfall is moving quickly from left to right and visa versa is might be FM or frequency shift keying, when it sounds like bidibididibidiidi it could be a signal for very simple data transmissions, when is sounds like grgrgrgrgrgrgrgrgrgrggr it probably is a digital signal. When it sounds like beep beep beeeep beep beeep then those signals are remnants of ancient communication between dinosaurs, they are still echoing around. That HP fellow who has invented the software defined radio must have been a very clever bastard. Who could come up with the idea to shift something 90°?

[@danpedersen55]

Great video 👍

[@Abdullu]

this is awesome! I noticed around 5:22 that you are using the "Hantek-6000 Ver2.2.7" software under Windows. So I guess you used a Hantek PC USB oscilloscope. Later on in the video, we see you working under Ubuntu/Linux. As a Linux user myself, I'm thinking about buying a PC oscilloscope, but I'm hesitant because of Linux support. Have you tried OpenHantek under Linux, and do you consider it on-par with Hantek's own Windows-only software?

[@DoctorVolt]

I used a Linux virtual machine to run the SDR software, because I was having trouble with the USB soundcard driver under Windows. I know that the OpenHantek software only runs with the 6022 scopes, so I have no experience with this. The software that came with it is quite crappy. So in the meantime I have replaced it by a conventional Rigol MSO5104,

[@leomartihart]

muchas gracias!!! Muy muy buen trabajo!!!!

[@DoctorVolt]

De nada 😊

[@bens4446]

Which is better, ESP32 version or Pi Pico 2 version?

[@stevekaatz5595]

Great video. Very informative. How did you set up your scope to see the 4 quadrature components "rolling"?

[@lmoline63601]

What is the brand and model of the soundcard with 2 input channels?

[@DoctorVolt]

See video description.

[@purvanshubokde6640]

Hey Dr.V will you send me the link of the PCB that you used in this video? I need this PCB to make my own SDR circuit for my Radio telescope building college project. I hope you will send the link for this PCB.

[@DoctorVolt]

sure: github.com/michalin/easysdr/tree/main/schematic/gerber Send these files to any PCB maker of your choice.

[@purvanshubokde6640]

@@DoctorVolt thanks you so much for the help, so i just save the complete Gerber file on GitHub and send it to PCB manufacturer?

[@purvanshubokde6640]

​Thank you​ so much @@DoctorVolt 🤩🤩🤩👍👍👍

[@largerification]

Does the ESP32 S3 have any advantage in performance over the already EOL original ESP32? Or maybe the specs that matter are the same?

[@DoctorVolt]

I found that the S3 is a bit faster than the classic ESP32. I estimate around 20% or so. I think this is due to its more efficient Xtensa LX 7 core.

[@weiwei-kg1te]

Hello! I made one, the sound card is connected to the computer hdsdr has a signal, ESP32 is connected to the computer, the frequency cannot be controlled, CLK2 output 100MHZ, can not be changed, CLK0 and CLK1 have no output, is it set incorrectly?

[@unixux]

Beautiful stuff. Can this be done on a zynq or another FPGA ?

[@DoctorVolt]

No, it's made for microcontrollers.

[@michaelnoardo3315]

what is the module you used?

[@DoctorVolt]

ESP32 Dev Module and CBT3253 analog multiplexer soldered on adapter board.

[@michaelnoardo3315]

@@DoctorVolt the CBT you soldered it yourself to the adapter board right? thank you

[@DoctorVolt]

@@michaelnoardo3315 Correct.

[@Erhannis]

So that's neat...but I can't say I'd want to listen to music at that quality, haha. Where do you think the quality loss occurs? Are the transmitted signals far, weak, and noisy? Is it some flaw of the chips? The board? The fundamental design of the receiver?

[@DoctorVolt]

AM in general has bad quality, because the audio bandwith is limited to 4.5 Kilohertz. Then there is fading and interference from other stations or appliances. And last I think that the circuit I was using there adds a lot of distortion.

[@Erhannis]

@@DoctorVolt Thanks - do you know what aspect of the circuit causes the distortion, and how to improve it?

[@jimglover6448]

Very good video! Unfortunately, it's not easy for me to find the multiplexer. But still... great video!

[@DoctorVolt]

I got it from Digikey

[@jimglover6448]

That was the first place I looked! They do have a lot of multiplexers with 3253 in the part number, but I'm not finding a perfect match. I suspect there is some leeway here.

[@mumujibirb]

i wonder if an improved version could be made with a higher frequency and with a Pi Pico, considering the higher clock Are there merits to using higher frequencies? Or is it just going to be more parasitic impedance prone?

[@mumujibirb]

Also what determines the maximum frequecy? Is it the processing speed of the digital interface?

[@DoctorVolt]

The maximum frequency is limited by the analog switch. It cannot go higher than 30MHz. There is newer SDR radio project that uses Pi Pico. 101-things.readthedocs.io/en/latest/radio_receiver.html

[@mumujibirb]

sorry i actually meant pi zero What about the bandwidth? Are there actually really much differences for large or small ones? Thanks

[@victorcarell5784]

very interesting video📟

[@RodHartzell]

I bet gnu-radio has your DRM decoder properly written and tested.

[@avdrys]

Hi nice video . Is it possible to buy Your designed PCB from PCBWAY ? Or this project is shared on the page ?

[@DoctorVolt]

No, but you can upload the gerber files from my Github and order them from there.

[@avdrys]

Thank U . 73! @@DoctorVolt

[@joruss]

That last one looked similar to NOAA weather data transmission

[@hafo821]

Very nice

[@jameskolby]

very cool!

[@weiwei-kg1te]

Excuse me: How does the sound card adjust the frequency when connecting the I and Q signals? Is the computer sending the command code to the ESP32 via USB?

[@DoctorVolt]

Exactly. The ESP32 sends the coarse frequency to the ESP32 over USB, the SDR software filters the exact frequency out of the I and Q samples from the soundcard.

[@weiwei-kg1te]

@@DoctorVolt Hello! I made one, the sound card is connected to the computer hdsdr has a signal, ESP32 is connected to the computer, the frequency cannot be controlled, CLK2 output 100MHZ, can not be changed, CLK0 and CLK1 have no output, is it set incorrectly?

[@Sultan___]

cant we use mic input for this ? i have a laptop and i dont have a line-in port... also "cheap chinese" external audio capture devices are very expensive in here... so.. is there any hope for me?? Thanks!

[@DoctorVolt]

Yes, you can. But in this case, you will see all the stations twice on either side of the waterfall. Also the sensitivity is less.

[@Sultan___]

@@DoctorVolt there are op-amps in the circuit, wouldn't it be too high for mic input voltage? Thanks!

[@DoctorVolt]

@@Sultan___ No, that's ok. Output volstage of the opamps is below 1V. You can also put a capacitor of around 1 microfarad to get rid of the DC bias. But for me it works even without.

[@graciusgratian]

Hello, can you name the music playing in the very first secons of the video? It's quite interesting.

[@DoctorVolt]

Unfortunately not. It's some random shortwave station I picked up with the SDR that I show in the video.

[@JxH]

On-Screen error: "KHz" multiple places. * kHz Sorry, pet peeve. 🙂