10 Common Mistakes Made With Software Defined Radio

@ejonesss

2023-11-19 18:29:57

can you use modern tv cable for the antenna as today's digital tv and cable modems can run in the ghz range?

or even with the right adaptor connect to the tv cable?

@lydiaruiz1017

2023-10-30 19:25:33

Hi, Great video. I am trying to use an AirSpy HF+ Discovery using SDSharp for my IC-7300. However, I keep getting the message "Port is not available" for the omniRig Sync. Do you have any suggestions on what mistake I am making? Thanks in advance.

@Graeme_Lastname

2023-10-26 18:14:10

You mentioned lack of space, so what would you recommend for a small, wide band RX antenna?

@fenech97

2023-10-22 17:44:52

Do you need a licence to transmit? -like the Radio Amateurs.

@jacquesmertens3369

2023-10-12 20:24:49

SDR Console is the best software for my cheap, tiny RTL dongle.
I wish it would support DAB and I wish there were a way to get rid of that stupid waterfall (but luckily you can narrow the window).
Thanks for the hint !!

@jakedillingham

2023-10-07 13:58:20

Can SDR sharp be used on a mac?

@frequencywatchers

2023-09-18 07:58:25

Its Crazy How I Learned And Figured All This Out By Myself, Like, 90% Of All These Things You Said I Have Figured Out Myself, Now Looking back, Damn, I needed To Watch Some Ytb Videos Like Yours :D

@TheOpticalFreak

2023-09-15 22:37:43

What about anroid software apps

@waynec369

2023-09-11 13:53:56

My new policy. When a video gets interrupted for an advert and I must wait more than 10 seconds for the advert to load, I leave a dislike for the video. Furthermore, when I am recommended a video more than twice that I have alread seen, it gets a thumbs down. My recommendations are simply a treadmill anymore. YT isn't listening to me, so maybe the content providers can get their attention. It's nothing personal.

@KennethiSlite

2023-08-16 10:17:31

Good video! Why not loop antennas? Small space and great performance.

@superhussein

2023-08-14 20:42:17

is it allowed to send death threats on amateur radio freqs?

@allancopland1768

2023-07-17 18:28:28

Horrible compressed audio. What were you thinking of?

@faskedfask8012

2023-07-04 14:52:16

I think, with high gain you can't damage your SDR reciever. Because gain doesn't matter of the circuit which is operation on sameway regardless to gain settings. Of course, you can damage your reciever by high wattage RF in your near radius and that is more important how you can damage your reciever. But IDK if it is possible. If there is someone who know more and tell me about how gain can cause circuit damage i will be pleasured. :)

@trevorhannabus2239

2023-06-01 08:55:15

Very well done, just the aspect of direction. A whip is omnidirectional and also frequency sensitive by its length. One could use a Yagi, but that has its frequency limitations too but will concentrate receiving in one direction, actually attenuating signals from other directions. . A log periodic is probably the answer for the higher frequencies, as it is directional and can handle a wider band of frequencies. But you will need a system that can turn it around to face different directions. (And maybe tilt from horizontal to vertical too) Now we have polarization too, vertical polarized means you need your Yaggi to be verticle position, the whip is vertical, a mode used in preference to horizontal. . Then we have balanced to unbalanced to balanced, the yaggi is balanced and most radios outputs are unbalanced. Here we use a "Balun" a 1/2 to 1/4 wavelength coax, connected between the two points on the folded dipole of the Yaggi. Many prefer a small transformer, air core or ferrite core. Coax is joined to earth, and one of the dipoles ends. On HF frequencies you can make a antenna tuning unit, which basically just adds length to the antenna by putting a coil in series, or shorten the antenna by purring a small cap in series. I suppose one can google the details of all these things. IMPORTANT - You will only need to do this if the stations you want to listen to are very weak. Antennas are the only thing you can tweek, I loved the machanisms I had to make to make my 12 element Yaggi wiz around in 360 degrees. It also could tilt up and down and twist it from verticle to horizontal. Hope this gets you started on making antennas.....lol

@FixitFrank

2023-05-30 16:37:30

This was a great video! I have been into SDR slightly more than causally for a few years but recently started to really get into it. I had not heard of SDR Console. Your channel is literally my favorite for tech content. Thank you and hello from the USA.

@orveahava

2023-05-30 10:40:40

Can you please reccomend a book that is specific enough but adequate for novice users that deals with - antennas, coax cables, filters, gain, resistance etc. - the bottom line here is what equipment to use for which frequencies. How to scan propperly etc.

@mayhem1994

2023-05-18 04:11:06

i cant even get it to scan

@whistl-om6ko

2023-05-08 17:46:13

Thanks. Useful info I needed to hear

@zvpunry1971

2023-05-06 10:19:14

The most important mistake that wasn't mentioned: Avoid proprietary soft- and hardware! Instead look for radios with open hardware interfaces, resulting in free (as in libre, not as in free beer) drivers that run everywhere and software that is also free (also as in libre and not as in free beer)! If you don't care about your freedom to learn how things work, your freedom to modify and experiment... then get the whatever you want, I don't care. But don't complain if you can't do the more advanced things with it.

I personally think, using free software is a absolute must in software defined radio!

With every physical radio, you can disassemble it an look inside how it is built and you can modify it. Even if it is a one chip solution, some people grind down chips layer for layer and put them under a microscope to reverse engineer them. Actually polish them down micrometer for micrometer and the microscope is a electron microscope, because the structures you look at are often smaller then the wavelength of visible light.

With software defined radios move all the "magic" into software. If the software isn't free, you have to reverse engineer it which may rival the complexity of grinding down a chip and reverse it under the microscope. Something most people can't effort. So you need access to functional blocks, their source code and documentation. Then playing with software defined radio becomes as easy as assembling a kit or building something from an existing design.

With proprietary software *only*, the radio hobby would die, because the design of most radios is nowadays a software defined radio. Fortunately free software and free hardware designs exist.

Some Examples of free Hardware Designs:

Ettus Research USRP: The Company Ettus Research started with the goal to build a low cost SDR that everyone can use, especially with GNURadio. But since then, their hardware became more and more capable and also more expensive. Their Hardware became a fundamental tool for the development of high bandwidth mimo systems like 5G and also used by the military for signals intelligence. They are now owned by National Instruments and their Radios have become prohibitively expensive (You have to decide if you want to buy a new luxury car or a radio). But they still release Hard- and Software designs and support the free software projects involved. And there are various Clones available.

ADALM Pluto: The company Analog Devices wants to sell ICs and a good way to do it, is to create open and inexpensive educational material that can be used to teach the next generation of engineers, when these start working for companies that build stuff, they use what they know and this is how to sell chips. ADALM stands for Analog Devices Advanced Learning Module, it is a very inexpensive but highly capable software defined radio. It contains a runtime-reconfigurable FPGA with two physical ARM CPU Cores that run Linux. The HDL source for the FPGA and all drivers for Linux are available, the result is that it just works and that people have built firmware for special purposes. Clones of the Hardware exist, some are even better then the original (Better TCXO, additional SMA connectors für RX2 and TX2, Metal case).

The HackRF One: Because the USRP was too expensive and something less expensive was needed to allow people to reverse engineer and audit wireless devices, the HackRF Project was started. It is also a completely free design and comes with free software to support it.

The above mentioned SDRs have one thing in common: No filters, a completely open frontend from ~1MHz to ~6000MHz, so you might easily overload them with strong out of band received signals. So a bandpass filter for the received band is advised. And on the TX side, it is also unfiltered and a low pass filter for the band used is always needed if you want to transmit.

Another Example of free Hardware Designs are all the OpenHPSDR designs. OpenHPSDR is a Project that created a lot of modules from ADC / DAC boards, amplifiers, filters, power supplies and so on. Control and transport of I/Q data happens via Internet Protocol over Ethernet. Based on this Design (Especially the protocol used over the network), many other SDR Transceivers were created. The ANAN or the Hermes Lite 2 or Charlie 25 are good examples of derived hardware designs.

Non-Free Hardware Design:

RTL2832U based USB TV-Receivers, probably the most popular SDR ever. It was actually just a proprietary/undocumented USB TV receiver, but a developer of linux drivers managed to discover a mode where the receiver starts sending I/Q data over USB. Now we have cheap entry level SDRs for everyone. But I don't consider it free, it was just a happy accident. Of course it is now very well supported by free software and the hardware is so cheap, it would be wrong to not mention it.

Some Examples of free Drivers:

UHD: The software to communicate with USRPs (and Clones).
libiio + libad9361 (and many more): The very modular driver framework to communicate with ADALM Pluto and similar Analog Devices hardware.
rtl-sdr: The software to communicate with RTL2832U based USB TV-Receivers.
hackrf: The software to communicate with the HackRF One.

The OpenHPSDR based Radios work over Ethernet / Internet Protocol, there is no direct Hardware access needed. The same can be true for UHD and libiio, if the Radio has a Network Interface. The rtl-sdr software comes with a tool called rtl_tcp which also allows to make a SDR accessible over the network.

Hardware Abstraction Layers

osmosdr: It makes different types of SDRs available with a single programming interface. You can add new hardware support to it and all programs that use it, can immediately access the new hardware. The user normally has nothing to do with osmosdr, except when some program uses it, you have to see if your hardware is supported by osmosdr and if it is, it is also supported by the program that uses osmosdr. Unfortunately the osmosdr project isn't very active maintained. It works for its intended purpose.

SoapySDR: Basically the same idea as osmosdr but written in C++ and actively maintained. It supports everything that is supported by osmosdr (because it can use osmosdr) and it has SoapyRemote, which makes all supported Hardware available over Network.

Programs that use osmosdr or SoapySDR:

gqrx: A simple AM/FM/SSB receiver application.
sdr++: A newer receiver application, more demodulators (it was mentioned in the video)
sdrangel: A transceiver application, you can receive and transmit AM/FM/SSB and various other modes.

Programs that use the HPSDR Protocol:

linhpsdr: A simple transceiver program for OpenHPSDR based radios.
pihpsdr: The same but optimized for the raspberry pi.

Programs for SDR rapid prototyping and frameworks:

GNU Radio: It is a large library of SDR components, building blocks. Filters, Modulators/Demodulators and input output modules, signal generators and so on. They can be used when you program something from scratch. But they can also used by the tool named "gnuradio-companion" where you drag and drop those blocks on a workspace and create connections between them. It is like building a radio from minicircuits modules, you get filters, mixers and so on and connect them.

Pothos: Basically the same idea as GNU Radio, but more focus on rapid prototyping like gnuradio-companion and less a library of SDR modules. The SoapySDR Project is part of it.

liquid-dsp: A library full of common digital signal processing routines to build software defined radios.

libvolk: A companion project for gnuradio, it contains common functions used in digital signal processing, like multiplying large arrays of numbers. But these functions have hardware specific optimizations.

Everything on a lower level is like winding your own coils and transformers to build your own radio. This is where I could list common programming languages like c, c++, python and so on. But this is already a wall of text. ;-)