Create Your Own Open-Source Software-Defined Radio

This video helps you build a budget Software-Defined Radio, all software free and open-source, with a single inexpensive component as the wideband radio-frequency front end, able to tune from 500 KHz to 1.7 GHz.

Included is a tutorial that explains how radio modulation schemes work -- CW, AM, SSB, FM and wide FM.

Also included are full instructions for a test transmitter written in three forms -- Python, Rust, and GnuRadio flowchart, all with source files, all free and open-source.

Keywords: Software-Defined Radio, SDR, SDR++, RTL-SDR V4, HackRF One, Heathkit AR-3

Index:

00:00 Introduction
02:05 Section I : Software-Defined Radio
02:23 SDR Basic Layout
02:36 Old Expensive Setup
03:07 New Economical Setup
03:47 SDR++ Program
04:04 Section II : A Little Theory
08:41 Section III : Radio Modes Survey
09:25 Radio Modes : CW
10:52 Radio Modes : SSB
12:13 Radio Modes : AM
13:22 Radio Modes : NFM
14:33 Radio Modes : WFM
15:42 Section IV : Reception Examples
16:06 WWV Time Standard Station
16:33 SSB Ham Radio
16:49 2 Meter NFM Ham Radio using Repeater
17:07 : AM Foreign-Language Broadcasts
18:14 UHF Electronic Devices Frequency
18:32 UHF Car Key Fob Frequency
18:53 UHF Z-Wave Home Automation Frequency
19:10 Family Radio Secvice (FRS) Band
19:53 VHF Air Band : Pilot / Tower Communication
20:44 Section V : Signal Generator Description
21:03 Hardware Configuration
21:20 GnuRadio Signal Generator Flowchart
21:37 Math Equations for all Modulation Modes
21:58 Feynman Math Quote
22:18 Linux & Windows Brief Setup Instructions
22:26 Windows 11 Advertisement Complaint
23:02 Windows 10/11 Pipe Failure Analysis
23:43 Section VI : Reflections
23:48 Crystal Radio
23:55 Apricot Picker Anecdote
23:59 Heathkit AR-3 Kit Purchase
25:26 Heathkit AR-3 Schematic Diagram Analysis
26:09 Closing Remarks
27:02 End

[dfkjbdfondfngg]

Thank you for making this. Wish I could spend a couple of months as an apprentice :) There is so much to learn from you!

[AlHearn]

This is one of the best videos of its kind that I've seen. Great job, not so much the SDR part, but the general radio part, which of course is important to understanding the purpose and function of SDR. Thank you for a great resource for up and coming SDR and radio enthusiasts. .

[JMSobie]

Thank you again, Paul. I tell my kids about a guy I heard of, who went opposite of everyone else and made a world of it. I drive a low-option stick car, do all my own repairs, got my ham license in 2015 and my first RTL-SDR a few years ago. And I love Linux and HATE Windows like poison. I'm eager to try an SDR program that isn't Windows-based. Always look forward to your videos!

[pierremartel]

I really like the way you explain that radio need the internet to work, but in fact it is the inverse. Been saying it for years.

[nikethunner]

So much information in there. Thanks to you for the work put in and thanks to the algorithm for recommending this to me, i guess.

[unhinged]

Thank you for this great instructional description of SDR, Paul. It is an extremely valuable resource in a subject area that can be pretty thin! When I go to your SDR website I just a blank screen (no error), however. Thank you!!

[jps]

Thanks for an interesting video!
A fascinating thing I’ve seen people do on YouTube with SDRs is receiving image data from weather satellites, never done it myself but always wanted to try.

[johnwest]

This video seems well organized, clear, and thorough. Thank you. Though if there's anything of importance that's confusing or left out for noobs I'd probably miss it because I already know too much about RF, (if that's possible.) I built my first tube transceiver kit in '63 at age 13. I don't talk much on the radio. I experiment. BTW, I often use the SSB trick to copy weak AM signals. Sometimes it makes a great difference, sometimes none at all depending on the reason for the hard to copy signal. I live in Boulder, CO only 60 or so miles from the WWV xmitter site, but at that distance, and me being set back a bit behind the foothills I'm at a bad distance in a very bad location to receive any but the WWVB signal. Thus my use of SSB to copy WWV on 5 MHz. It seems silly that I have a hard time copying WWV when the rest of the USA has little problem, especially since I actually sometimes do work for NIST. I'm going to do a little building project and give a high Q mag-loop with a tuned pre-amp and a narrow-band filter a try and see how I do. Again, thanks for the video.

[maartenc]

Thanks for this great video. Loved watching it.
My first steps as a ham in SDR was by buying a flexradio the flex 1500. And loved it very much. The only downfall was that flexradio stopped supporting it, so one day in the future windows update will break the system.
That is the main reason why my next radio must be open source and why I indefinitely switched to Linux. Running an Ubuntu based distro and starting again in SDR.

One comment about your video. There is another advantage of FM in favor of AM.
In AM, since the Amplitude is chancing you can get LFI (Low frequency Interference). That is that an audio amplifier can behave as a simple crystal detector and you be audible over a speaker system our an old gramophone. Since FM has a more our less stable power output it is more friendly in overpopulated areas as in my country The Netherlands.

Just want to say love your video and have subscribed to your channel.
73 de PA5MC ... -.-

[asarangan]

A very nice review. I am at least two or three decades behind you in age, but I am of the same type - I love building things with my hands, whether it is cars, planes (yes planes), radios or computers. As for Linux vs Windows, I think they both have a place. I use Linux for technical work, and windows for casual stuff like watching movies. What bothers me is a new generation of engineers and computer scientists who only know Windows.

[dalesmith]

Very interesting and well done OM! But I thought we would build an SDR PGM from the ground up, lets say C++, Qt, Ettus USRP/UHD etc.! hi-hi!
That's what I was doing tonight. Struggling with BOOST, QT and UHD! And OH YA,
73's
Dale
ve3aam
btw, I miss the tubes, but grew up with them Still have a couple thousand on hand! Smallest, acorn, biggest, 4cx35000c!
1959 model year here.
But do love the "Three Legged Fuses" and all of those ridiculous Surface Mount! Not really a fan of SM!, But the power of FPGA's, nuts!!

[radiofun]

Very good & interesting video, many thanks! On my channel there are a few first try SDR setups for SW. 10 May 2024. I (1955) also had, in the very past (1960's-1970's) a very limited budget when I wanted to do this hobby, radio.

[moa]

Thank you for your involvement ! great job .

[erlendse]

Please call it "rtl-sdr blog v4", rtl-sdr is the hardware driver, and "v4" alone is meaningless. The page selling them is "rtl-sdr blog".
Internally it have upconverter(similar to ham-it-up) for HF, and tuner/down-converter with filtering to isolate stuff to a analog low frequency(single digit MHz) signal.
As in it's a full analog radio frontend going to a analog to digital converter.
The rest is ADC+digital down-convert that can be looked up online for the specially interested.

[Test--Echo]

Good video. You have a voice that is relaxing to listen to.