Tagged: plutosdr

Software Defined Radio for Engineers: Free University Level Text Book with PlutoSDR Examples

Analog Devices has recently released a new text book for free called "Software-Defined Radio for Engineers, 2018". This is an advanced university level text book that covers communication systems theory as well as software defined radio theory and practice. The book uses the PlutoSDR as reference hardware and for practical examples. The PlutoSDR is Analog Devices $150 RX/TX capable SDR that was released about a year ago.

The objective of this book is to provide a hands-on learning experience using Software Defined Radio for engineering students and industry practitioners who are interested in mastering the design, implementation, and experimentation of communication systems. This book provides a fresh perspective on understanding and creating new communication systems from scratch. Communication system engineers need to understand the impact of the hardware on the performance of the communication algorithms being used and how well the overall system operates in terms of successfully recovering the intercepted signal.

This book is written for both industry practitioners who are seeking to enhance their skill set by learning about the design and implementation of communication systems using SDR technology, as well as both undergraduate and graduate students who would like to learn about and master communication systems technology in order to become the next generation of industry practitioners and academic researchers. The book contains theoretical explanations about the various elements forming a communication system, practical hands-on examples and lessons that help synthesize these concepts, and a wealth of important facts and details to take into consideration when building a real-world communication system.

The companion site for the book which contains links to complimentary online lectures, slides, and example MATLAB code can be found at https://sdrforengineers.github.io. MATLAB is a very powerful programming language and toolset used by scientists and engineers. MATLAB is not a cheap tool, but there is a home user licence available for a more reasonable price. To do some of the exercises in the book you'll probably at least require the core MATLAB plus the Communications System Toolkit which is an extra add on.

The full book can be purchased as a Hardcover from Amazon, or downloaded freely online as a PDF.

If you're interested in a similar book, there is also the free DesktopSDR book which uses RTL-SDR dongles for the practical examples.

SDR For Engineers Book
SDR For Engineers Book

Real Time Passive Radar Running Native on the ADALM-PLUTO ARM CPU

The ADALM-Pluto (aka PlutoSDR) is a US$149 TX/RX capable SDR that we have posted about several times in the past. It has a tuning range from 70 MHz to 6000 MHz with a bandwidth of up to 56 MHz (with software hack applied). One additional useful feature on the PlutoSDR is it's built in ARM CPU, which can be used to run programs on board the SDR itself. 

Over on his blog Mike has shown how he implemented simple passive radar code on the PlutoSDR's ARM processor. This means that no PC or other hardware is required to process the data, the entire script can be run via a SSH connection to the PlutoSDR. Mike doesn't seem to have shared his script anywhere, but one of his previous posts explains the process. The script creates the video in real time on board the PlutoSDR's ARM CPU, which is then streamed via ffplay to a PC with a screen. On his second post Mike shows some extra videos of passive radar working with FM Broadcast and DVB-T signals.

Passive radar is a radio technique allows you to detect and track RF reflective objects such as aircraft using strong signals from already existing transmission towers, such as broadcast FM or DVB-T signals.

Transmitting DVB-S with a PlutoSDR and Receiving it with an RTL-SDR

Over on YouTube Christopher Bridges has uploaded a video showing him using a PlutoSDR and a GNU Radio program to transmit a DVB-S signal, which is then received with an RTL-SDR. DVB-S is a digital video broadcasting standard designed for satellite transmissions and digital amateur television video (DATV) also uses DVB-S in the 1.2 GHz amateur band. In this example the PlutoSDR transmits at 1.28 GHz.

Chris uses the rtl_sdr command line software to receive the raw IQ data at 1 MSPS, and then uses the leandvb software to decode the raw IQ file directly into a video file.

If you’re interested in TXing DVB-S/DATV but don’t have a transmit capable SDR, then we note that even a Raspberry Pi just by itself can be used to transmit it with rpidatv.

Linux gnuradio QPSK DVBS PlutoSDR + rtl MacBook leansdr

Linux gnuradio QPSK DVBS PlutoSDR + rtl MacBook leansdr

PlutoSDR Quickstart Guide

This guide is intended to get you set up with your PlutoSDR quickly and easily on either Linux or Windows. We also show how to apply a simple software ‘hack’ to your PlutoSDR to extend its frequency range to about 70 MHz to 6000 MHz and bandwidth to 56 MHz.

Applying the Frequency + Bandwidth Expansion Hack

Note that the Windows SDR# plugin requires this hack to be performed first, which is why we put this hack at the top. This hack tricks the PlutoSDR firmware into thinking is has the AD9364 chip. As the AD9363 and AD9364 chips are very similar this works. Note that you do this at your own risk, but we feel that the risk is very low.

This tutorial is for Windows and PuTTY, but could be applied to any OS and terminal software

  1. If you don’t have it already, download the terminal emulator software PuTTY from putty.org.
  2. Plug in your PlutoSDR on the USB port.
  3. Open Windows Device Manager, and expand the Ports (COM & LPT) entry. Take a note of what COM port the PlutoSDR Serial Console is using. In the screenshot ours is using COM6. Close device manager after.
     
     
  4. Open PuTTY and select the ‘serial’ button.
  5. Under ‘Serial line’ type in the COM port the PlutoSDR is using. In our case we type COM6.
     
     
  6. Press Open and you should be greeted with a login screen.
  7. Login with the credentials username: root, password: analog.

Now follow the instructions in the following screenshot image, typing in the three commands as they appear.

PlutoSDR Upgrade instructions

An example of the commands being entered in PuTTY

After doing a reset your PlutoSDR should now be upgraded to the full frequency range and bandwidth.

Windows PlutoSDR SDR# Setup

  1. Download the Windows Drivers from here. Choose the latest version of the PlutoSDR-M2k-USB-Drivers.exe download.
      
  2. Run the installer and complete the installation by clicking through the prompts.
     
  3. Plug in your PlutoSDR. Windows should automatically recognize the PlutoSDR and a folder containing the PlutoSDR config file may pop up. PlutoSDR creates a USB disk drive, USB network connection and a USB serial port. You can confirm in Windows Device Manager if these interfaces have been added.
     
  4. Download and extract SDR# into a folder of your choice from airspy.com/download. Make sure that you download the x86 version, do NOT download the x64 version.
      
  5. Grab the current release of the SDR# PlutoSDR plugin from here. Download the sdrsharp-plutosdr-x.x.x.zip file.
      
  6. Extract the contents of the PlutoSDR SDR# plugin zip file into your SDR# folder.
      
  7. In the SDR# folder find the “FrontEnds.xml” file. Right click it and go to “Open With” open it with Notepad, or any other text editor of your choosing.
      
  8. Before the </frontendPlugins> closing tag, add the PlutoSDR key <add key=”PlutoSDR” value=”SDRSharp.PlutoSDR.PlutoSDRIO,SDRSharp.PlutoSDR” />, and then save and close Notepad.
     
     
  9. Open SDR# and under the Source pull down box choose PlutoSDR.
      
  10. Open the properties box by clicking on the cog icon which is next to the play button. In the default Connection tab ensure the Device-URI is “ip:192.168.2.1”, and then click on “Connect”.
      
  11. Still in the properties box go to the “Receiver tab”. Choose a sample rate up to or below 4 MSPS. Higher sample rates can be selected if desired, but note that you will have dropped samples (e.g. choppy audio). This is a hardware limitation of the PlutoSDR. (Note that there currently seems to be a bug where if you mouse over the FFT or waterfall parts of SDR# then the PlutoSDR config box will be sent to the background. Move the config box to the very left to avoid this. If it disappears just click the cog icon to get it back. If you can’t move it because you’ve moved it too far to the right, minimize SDR# and frag it back to the left.)
      
  12. Press close the configuration box, and then press the Play button in SDR#. The PlutoSDR should now be running.
     
     
  13. Open the configuration box again to adjust the gain.
     

Linux Instructions (Still Coming)

Comments Off on PlutoSDR Quickstart Guide Posted in Tagged with

Opening a Car and Garage Door With PlutoSDR

Over on his YouTube channel Tysonpower (aka Manuel) has uploaded a video showing how he was able to use his PlutoSDR to perform some simple replay attacks that open his garage and car doors. To do this he records the signal from the wireless keyfobs with the PlutoSDR, and then uses a GNU Radio program to replay that signal again at a later time. From the tests he concludes that the PlutoSDR can be a great cheaper alternative to a HackRF, with the PlutoSDR coming in at $100 vs $300 for the HackRF.

To get around the rolling code security on his car he records the keyfob with the PlutoSDR while it’s out of the wireless range of his car, so that the rolling code will not be invalidated. Then later closer to the car the PlutoSDR is used to replay the car keyfob signal which opens the door.

Note that Tysonpower’s video is narrated in German, but English subtitles are available through the YouTube interface.

[EN subs] Hacken eines Autos und Garagentors – AdalmPluto Replay Attacke

[EN subs] Hacken eines Autos und Garagentors - AdalmPluto Replay Attacke

ADALM-Pluto 2-tone Test at 144 MHz

Over on his YouTube channel Adam 9A4QV has been testing his ADALM-PLUTO SDR in the 2M ham band at around 144 MHz. In one of his videos he shows a 2-tone test. A 2-tone test is used to determine how well an SDR can handle two strong narrowband signals at once, without causing intermodulation and imaging problems. The two tones in his video occur with real world signals on the 2M band when two amateur radio operators are transmitting strong signals at the same time.

The video shows that the Pluto SDR has some intermodulation problems occurring when the two strong signals transmit at once. No problems are noticed when only one signal transmits.

Problems like this with the PlutoSDR may be expected as it was never designed to be a high performance receiver, but rather a tool for learning and experimentation. But it is still possible to use it as a more general purpose receiver if you are aware of the limitations.

ADALM-PLUTO 2-tone test 144MHz

ADALM-PLUTO 2-tone test 144MHz

L-Band and 6GHz Tests with the ADALM-PLUTO SDR

Over on YouTube Adam 9A4QV has uploaded two videos that show his tests with the ADALM-PLUTO SDR on the L-band and up at 6 GHz. In his first video the L-band test shows that the receiver is quite sensitive in this region, managing to receive L-band satellites without any LNA. Although he also tests reception with an LNA4ALL in the receive chain, and this still does improve reception even more.

In the second video Adam confirms that reception is available up to 6 GHz using a PlutoSDR with frequency extension hack enabled.

ADALM-PLUTO / LNA4ALL @ L-band

ADALM-PLUTO / LNA4ALL @ L-band

ADALM-PLUTO test on 6GHz

ADALM-PLUTO test on 6GHz

Some Further Tests with the ADALM-PLUTO SDR

Last week we posted about the unboxing of the ADALM-PLUTO SDR as well as some information about a hack that can be used to increase the tuning and bandwidth range of the SDR. In this post we show some initial tests and first impressions of the the receive performance of the SDR.

We tested the PlutoSDR on a number of frequencies, some in the default tuning range, and some in the frequencies enabled by the hack. In terms of sensitivity not much difference was noticed in the expanded frequencies. Sensitivity overall is decent and seems to be comparable to other SDRs. However, the PlutoSDR does suffer quite heavily from out of band imaging. Although there is a 12-bit ADC being used, filtering is still necessary for many signals. Broadcast FM, DAB, HDTV and GSM are all very problematic and images of these signals can be found all over the spectrum if they are strong. Above about 800 MHz two broadcast FM stations show up in the exact same place at all frequencies, no matter the gain setting.

Imaging is probably expected as the IIP3 spec of the AD9363 RF chip used in the PlutoSDR is not that great at only -18 dBm at max gain. Other SDRs like the Airspy Mini and RSP2 don’t have imaging anywhere as bad as the PlutoSDR as they have naturally high dynamic range in the case of the Airspy and filter banks built-in in the case of the RSP2.

Below are some example screenshots of the imaging we saw from strong signals. We used SDR# with the new PlutoSDR plugin, and set the sampling rate to 3 MSPS. On these screenshots we note that turning down the gain did not help, so these images were present in some way no matter the gain settings. There is probably still some optimization to go in the SDR# plugin, so it’s possible that imaging could be reduced with further work.

DAB Appearing at 79 MHz

DAB Appearing at 79 MHz

GSM at 133 MHz

GSM at 133 MHz

No imaging here (see next slide)

No imaging here (see next slide)

But moved 1 MHz up and there is heavy imaging

But moved 1 MHz up and there is heavy imaging

GSM @ 315 MHz

GSM @ 315 MHz

BCFM Pulsing in at 415 MHz

BCFM Pulsing in at 415 MHz

BCFM interference shows up like this at all frequencies above 800 MHz

BCFM interference shows up like this at all frequencies above 800 MHz

To test sensitivity we recorded audio on a few weak signals that did not have any images present, and we kept the gain at the highest it could go without the noise floor rising or images showing up.

Again we used SDR# with the PlutoSDR plugin, and set the sampling rate to 3 MSPS. We note that anything higher than 4 MSPS causes lost samples and thus jittery audio as this is the hardware limit of the PlutoSDR.

BCFM

This is a weak BCFM station. The PlutoSDR actually seemed to receive it better than the Airspy Mini. The RSP2 could not receive it, and the weak audio heard on the RSP2 is audio from an image.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

161 MHz

This is a voice weather station. Here the PlutoSDR was very comparable to the Airspy Mini and RSP2. Not much sensitivity degradation in the ‘hacked’ expanded frequency range.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

858 MHz

This is a digital trunking signal (there was no stable voice source this high to test with). Sensitivity is about the same as the other SDRs.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

BCAM (Night)

A night time BCAM test. The PlutoSDR was coupled with a SpyVerter. Performance was quite good and on par with the Airspy Mini.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

L-Band

Tested reception with a L-band patch antenna (no external LNA). Tested STD-C reception too. The PlutoSDR worked very well on L-band and had similar performance to the SDRplay. The Airspy is not good at L-band without an LNA and could not receive the STD-C channel by itself.

PlutoSDR

PlutoSDR

PlutoSDR STD-C

PlutoSDR STD-C

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

SDRplay RSP2 STD-C

SDRplay RSP2 STD-C

Conclusion

It’s clear that the PlutoSDR wasn’t made to be a general purpose high performance SDR, but rather a hackers/experimenters/learning SDR.  Performance in terms of out of band imaging is not great, and for any real listening filters may be required. That said, the performance is overall still not bad and overall still a bit better than an RTL-SDR or HackRF. With filtering the performance could be comparable to something like the Airspy Mini or SDRplay RSP2. Performance on L-band is very good, assuming you can filter or use a directional antenna to attenuate strong blocking signals. It’s also possible that further tweaks to the filter settings of the SDR# PlutoSDR plugin could improve imaging problems.

It’s also a bit disappointing that the maximum sample rate available is only 4 MSPS without drops. So this is the highest rate that you can use if you want to decode a signal, or listen to audio. For wideband waterfalls or spectrum analysis or other applications tolerant to dropped samples it should be possible to go up to the full 61.44 MSPS.

All in all, if you are interested in a low cost wideband SDR that does almost everything including TX, and are not too concerned about strong signals, images and overload, then this is still a great purchase at $99 USD (Digikey out of stock now, available for $149 on the Analog.com store). This SDR should be especially interesting to you if you are an SDR hacker/experimenter/student or are a fan of cheap SDRs/RTL-SDR/HackRF etc. If you are a ham or DXer and want something that just works with your high performance antennas and strong signals then you might look elsewhere.

On Twitter others have come to similar conclusions.

Software Defined Radio for Engineers: Free University Level Text Book with PlutoSDR Examples

Analog Devices has recently released a new text book for free called "Software-Defined Radio for Engineers, 2018". This is an advanced university level text book that covers communication systems theory as well as software defined radio theory and practice. The book uses the PlutoSDR as reference hardware and for practical examples. The PlutoSDR is Analog Devices $150 RX/TX capable SDR that was released about a year ago.

The objective of this book is to provide a hands-on learning experience using Software Defined Radio for engineering students and industry practitioners who are interested in mastering the design, implementation, and experimentation of communication systems. This book provides a fresh perspective on understanding and creating new communication systems from scratch. Communication system engineers need to understand the impact of the hardware on the performance of the communication algorithms being used and how well the overall system operates in terms of successfully recovering the intercepted signal.

This book is written for both industry practitioners who are seeking to enhance their skill set by learning about the design and implementation of communication systems using SDR technology, as well as both undergraduate and graduate students who would like to learn about and master communication systems technology in order to become the next generation of industry practitioners and academic researchers. The book contains theoretical explanations about the various elements forming a communication system, practical hands-on examples and lessons that help synthesize these concepts, and a wealth of important facts and details to take into consideration when building a real-world communication system.

The companion site for the book which contains links to complimentary online lectures, slides, and example MATLAB code can be found at https://sdrforengineers.github.io. MATLAB is a very powerful programming language and toolset used by scientists and engineers. MATLAB is not a cheap tool, but there is a home user licence available for a more reasonable price. To do some of the exercises in the book you'll probably at least require the core MATLAB plus the Communications System Toolkit which is an extra add on.

The full book can be purchased as a Hardcover from Amazon, or downloaded freely online as a PDF.

If you're interested in a similar book, there is also the free DesktopSDR book which uses RTL-SDR dongles for the practical examples.

SDR For Engineers Book
SDR For Engineers Book

Real Time Passive Radar Running Native on the ADALM-PLUTO ARM CPU

The ADALM-Pluto (aka PlutoSDR) is a US$149 TX/RX capable SDR that we have posted about several times in the past. It has a tuning range from 70 MHz to 6000 MHz with a bandwidth of up to 56 MHz (with software hack applied). One additional useful feature on the PlutoSDR is it's built in ARM CPU, which can be used to run programs on board the SDR itself. 

Over on his blog Mike has shown how he implemented simple passive radar code on the PlutoSDR's ARM processor. This means that no PC or other hardware is required to process the data, the entire script can be run via a SSH connection to the PlutoSDR. Mike doesn't seem to have shared his script anywhere, but one of his previous posts explains the process. The script creates the video in real time on board the PlutoSDR's ARM CPU, which is then streamed via ffplay to a PC with a screen. On his second post Mike shows some extra videos of passive radar working with FM Broadcast and DVB-T signals.

Passive radar is a radio technique allows you to detect and track RF reflective objects such as aircraft using strong signals from already existing transmission towers, such as broadcast FM or DVB-T signals.

Transmitting DVB-S with a PlutoSDR and Receiving it with an RTL-SDR

Over on YouTube Christopher Bridges has uploaded a video showing him using a PlutoSDR and a GNU Radio program to transmit a DVB-S signal, which is then received with an RTL-SDR. DVB-S is a digital video broadcasting standard designed for satellite transmissions and digital amateur television video (DATV) also uses DVB-S in the 1.2 GHz amateur band. In this example the PlutoSDR transmits at 1.28 GHz.

Chris uses the rtl_sdr command line software to receive the raw IQ data at 1 MSPS, and then uses the leandvb software to decode the raw IQ file directly into a video file.

If you’re interested in TXing DVB-S/DATV but don’t have a transmit capable SDR, then we note that even a Raspberry Pi just by itself can be used to transmit it with rpidatv.

Linux gnuradio QPSK DVBS PlutoSDR + rtl MacBook leansdr

Linux gnuradio QPSK DVBS PlutoSDR + rtl MacBook leansdr

Opening a Car and Garage Door With PlutoSDR

Over on his YouTube channel Tysonpower (aka Manuel) has uploaded a video showing how he was able to use his PlutoSDR to perform some simple replay attacks that open his garage and car doors. To do this he records the signal from the wireless keyfobs with the PlutoSDR, and then uses a GNU Radio program to replay that signal again at a later time. From the tests he concludes that the PlutoSDR can be a great cheaper alternative to a HackRF, with the PlutoSDR coming in at $100 vs $300 for the HackRF.

To get around the rolling code security on his car he records the keyfob with the PlutoSDR while it’s out of the wireless range of his car, so that the rolling code will not be invalidated. Then later closer to the car the PlutoSDR is used to replay the car keyfob signal which opens the door.

Note that Tysonpower’s video is narrated in German, but English subtitles are available through the YouTube interface.

[EN subs] Hacken eines Autos und Garagentors – AdalmPluto Replay Attacke

[EN subs] Hacken eines Autos und Garagentors - AdalmPluto Replay Attacke

ADALM-Pluto 2-tone Test at 144 MHz

Over on his YouTube channel Adam 9A4QV has been testing his ADALM-PLUTO SDR in the 2M ham band at around 144 MHz. In one of his videos he shows a 2-tone test. A 2-tone test is used to determine how well an SDR can handle two strong narrowband signals at once, without causing intermodulation and imaging problems. The two tones in his video occur with real world signals on the 2M band when two amateur radio operators are transmitting strong signals at the same time.

The video shows that the Pluto SDR has some intermodulation problems occurring when the two strong signals transmit at once. No problems are noticed when only one signal transmits.

Problems like this with the PlutoSDR may be expected as it was never designed to be a high performance receiver, but rather a tool for learning and experimentation. But it is still possible to use it as a more general purpose receiver if you are aware of the limitations.

ADALM-PLUTO 2-tone test 144MHz

ADALM-PLUTO 2-tone test 144MHz

L-Band and 6GHz Tests with the ADALM-PLUTO SDR

Over on YouTube Adam 9A4QV has uploaded two videos that show his tests with the ADALM-PLUTO SDR on the L-band and up at 6 GHz. In his first video the L-band test shows that the receiver is quite sensitive in this region, managing to receive L-band satellites without any LNA. Although he also tests reception with an LNA4ALL in the receive chain, and this still does improve reception even more.

In the second video Adam confirms that reception is available up to 6 GHz using a PlutoSDR with frequency extension hack enabled.

ADALM-PLUTO / LNA4ALL @ L-band

ADALM-PLUTO / LNA4ALL @ L-band

ADALM-PLUTO test on 6GHz

ADALM-PLUTO test on 6GHz

Some Further Tests with the ADALM-PLUTO SDR

Last week we posted about the unboxing of the ADALM-PLUTO SDR as well as some information about a hack that can be used to increase the tuning and bandwidth range of the SDR. In this post we show some initial tests and first impressions of the the receive performance of the SDR.

We tested the PlutoSDR on a number of frequencies, some in the default tuning range, and some in the frequencies enabled by the hack. In terms of sensitivity not much difference was noticed in the expanded frequencies. Sensitivity overall is decent and seems to be comparable to other SDRs. However, the PlutoSDR does suffer quite heavily from out of band imaging. Although there is a 12-bit ADC being used, filtering is still necessary for many signals. Broadcast FM, DAB, HDTV and GSM are all very problematic and images of these signals can be found all over the spectrum if they are strong. Above about 800 MHz two broadcast FM stations show up in the exact same place at all frequencies, no matter the gain setting.

Imaging is probably expected as the IIP3 spec of the AD9363 RF chip used in the PlutoSDR is not that great at only -18 dBm at max gain. Other SDRs like the Airspy Mini and RSP2 don’t have imaging anywhere as bad as the PlutoSDR as they have naturally high dynamic range in the case of the Airspy and filter banks built-in in the case of the RSP2.

Below are some example screenshots of the imaging we saw from strong signals. We used SDR# with the new PlutoSDR plugin, and set the sampling rate to 3 MSPS. On these screenshots we note that turning down the gain did not help, so these images were present in some way no matter the gain settings. There is probably still some optimization to go in the SDR# plugin, so it’s possible that imaging could be reduced with further work.

DAB Appearing at 79 MHz

DAB Appearing at 79 MHz

GSM at 133 MHz

GSM at 133 MHz

No imaging here (see next slide)

No imaging here (see next slide)

But moved 1 MHz up and there is heavy imaging

But moved 1 MHz up and there is heavy imaging

GSM @ 315 MHz

GSM @ 315 MHz

BCFM Pulsing in at 415 MHz

BCFM Pulsing in at 415 MHz

BCFM interference shows up like this at all frequencies above 800 MHz

BCFM interference shows up like this at all frequencies above 800 MHz

To test sensitivity we recorded audio on a few weak signals that did not have any images present, and we kept the gain at the highest it could go without the noise floor rising or images showing up.

Again we used SDR# with the PlutoSDR plugin, and set the sampling rate to 3 MSPS. We note that anything higher than 4 MSPS causes lost samples and thus jittery audio as this is the hardware limit of the PlutoSDR.

BCFM

This is a weak BCFM station. The PlutoSDR actually seemed to receive it better than the Airspy Mini. The RSP2 could not receive it, and the weak audio heard on the RSP2 is audio from an image.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

161 MHz

This is a voice weather station. Here the PlutoSDR was very comparable to the Airspy Mini and RSP2. Not much sensitivity degradation in the ‘hacked’ expanded frequency range.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

858 MHz

This is a digital trunking signal (there was no stable voice source this high to test with). Sensitivity is about the same as the other SDRs.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

BCAM (Night)

A night time BCAM test. The PlutoSDR was coupled with a SpyVerter. Performance was quite good and on par with the Airspy Mini.

PlutoSDR

PlutoSDR

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

L-Band

Tested reception with a L-band patch antenna (no external LNA). Tested STD-C reception too. The PlutoSDR worked very well on L-band and had similar performance to the SDRplay. The Airspy is not good at L-band without an LNA and could not receive the STD-C channel by itself.

PlutoSDR

PlutoSDR

PlutoSDR STD-C

PlutoSDR STD-C

Airspy Mini

Airspy Mini

SDRplay RSP2

SDRplay RSP2

SDRplay RSP2 STD-C

SDRplay RSP2 STD-C

Conclusion

It’s clear that the PlutoSDR wasn’t made to be a general purpose high performance SDR, but rather a hackers/experimenters/learning SDR.  Performance in terms of out of band imaging is not great, and for any real listening filters may be required. That said, the performance is overall still not bad and overall still a bit better than an RTL-SDR or HackRF. With filtering the performance could be comparable to something like the Airspy Mini or SDRplay RSP2. Performance on L-band is very good, assuming you can filter or use a directional antenna to attenuate strong blocking signals. It’s also possible that further tweaks to the filter settings of the SDR# PlutoSDR plugin could improve imaging problems.

It’s also a bit disappointing that the maximum sample rate available is only 4 MSPS without drops. So this is the highest rate that you can use if you want to decode a signal, or listen to audio. For wideband waterfalls or spectrum analysis or other applications tolerant to dropped samples it should be possible to go up to the full 61.44 MSPS.

All in all, if you are interested in a low cost wideband SDR that does almost everything including TX, and are not too concerned about strong signals, images and overload, then this is still a great purchase at $99 USD (Digikey out of stock now, available for $149 on the Analog.com store). This SDR should be especially interesting to you if you are an SDR hacker/experimenter/student or are a fan of cheap SDRs/RTL-SDR/HackRF etc. If you are a ham or DXer and want something that just works with your high performance antennas and strong signals then you might look elsewhere.

On Twitter others have come to similar conclusions.

PlutoSDR SDR# Plugin + New Dual Core CPU Hack

A new plugin for SDR# has been released which allows SDR# to be used with the ADALM-PLUTO SDR. To use the plugin you’ll have to apply the frequency range hack first, which allows the PlutoSDR to tune to 70 – 6000 MHz. Then simply extract the plugin to the SDR# directory and add the key to the FrontEnds.xml file.

We tested the plugin out and found that it worked well with our PlutoSDR. The interface allows you to set the sample rate up to 19 MSPS, but anything over 4 MSPS causes dropped samples and anything over 5 MSPS is labelled as not supported. The advertised hardware limit of the PlutoSDR with no dropped samples is 4 MSPS, and we did notice audio jitter at 5 MSPS and above. Anything higher than 5 MSPS shows noticeable jitter in the waterfall display too. Note that this is not a problem of the plugin or SDR#, but rather of the hardware limitations.

Over on the PlutoSDR forums user jocover also discovered a new hack which allows you to enable dual-core support on the PlutoSDR. It’s not clear if this helps with anything useful yet, but maybe useful for some custom applications that make use of the CPU.

PlutoSDR running in SDR#
PlutoSDR running in SDR#