SDR under Linux or Windows?

  • Just a question to the experienced SDR freaks..

    Is it worth trying this under Windows or would you rather try it under Linux?

    I'm running SDR# under Windows 10 but for some reason it started crashing more often during the last 2 weeks..

    I have an Airspy, my Funcube dongle is currently in use on my Raspberry PI 3+ and FOXTLM, but two more 0.5ppm SDR dongles from China are on it's way ;-)

    73s Peter DB2OS

    Peter Gülzow | DB2OS | AMSAT-DL President | member since 1983 | JO42VG

  • Hello DB2OS,

    as i have no experience with Linux i can't say anything about GQRX.

    I am using HDSDR which consumes a lot fewer CPU ressources and does really seldom crash. (only once this year here). SDR# crashes once a day on my slow PCs.

    Maybe HDSDR is a possible alternative to SDR# for you.

    vy73 DB8TF

  • Just a question to the experienced SDR freaks..

    Is it worth trying this under Windows or would you rather try it under Linux?

    I have only experience with gqrx under Linux and it works fine (no crashes).

    There is a dedicated site

    I currently use an SDRplay RSP1a for Es'hail-2 reception but the program also supports the RTL-SDR sticks.

    Of course there are also other SDR programs for Linux, e.g. CubicSDR.

    We'll have to find what is the easiest way of incorporating some form of locking.

    gqrx has a nice remote-control interface but it has only a single receiver.

    CubicSDR can run multiple receivers in the passband (so you can listen to more than one transmission at the same time) which could be nice as a starting point for locking to the beacon.

    However, at the moment I can not run it on my system due to a bug in combination with the native Nvidia OpenGL driver. First have to find how to work around that.

    DB8TF is right in that most of the programs appear to be "optimized for ease of programming" rather than for "least CPU usage". However on a machine that isn't 10 years behind current state-of-the-art you still can use it.

    (e.g. I have a Core2 Duo CPU E6850 @ 3.00GHz)

  • Peter,

    I confirm that sdr# latest versions are unstable.

    valid alternatives to SDR# under Windows:






    Also, good

  • Peter,

    I would like to suggest using a Linux distro and all the open source tools of the satellite community will be available to you. Running modern versions of e.g. gpredict, gqrx (and someday its follow-up), strf and numerous other things.

    It would be great to see more HAMs using all this stuff ;-)

  • Well, I had DualBoot Ubuntu and Windows on my Desktop and Laptop for a long time too, but I never made the switch to Linux.. Basically I do everything under Windows and hate to say it but Win10 works surprisingly good and stable.. Would SDR hardware work with a Virtual Machine running Linux on a WIN10 with i7 DualCore or QuadCore @ 2.67 GHz?

    Update: Actually made a quick Google search..

    Is about LimeSDR, but should also be OK with other hardware..

    Let's see what happens when the #P4-A transponders will be available for general usage. I think we will see a lot of interesting SDR based stuff...

    Peter Gülzow | DB2OS | AMSAT-DL President | member since 1983 | JO42VG

  • DB2OS :

    I understand... DualBoot usually isn't the best way to become accustomed to a system, because when you boot Linux you probably are locked out of your information like e-mail, documents, etc (this of course depends on your setup) and it always is just a temporary excursion.

    I am from a Unix background, my first experience with computers was on a PDP11/40 with Unix version 6, and it is like "the normal OS" for me. At home, I had the usual 8-bit stuff and later the 68000-based Atari ST, but I never considered spending money on a PC clone as it ran only MS-DOS which had so much trouble with multitasking and memory management (although I helped lots of people setting up systems with my packet radio software, DesqView and F6FBB BBS, all cross-developed on my Atari ST).

    When Linux came out, this was like a godsend. I built a 486 system with 16MB RAM, high-end for that time, installed it and immediately had a 32-bit multitasking system with demand paging and a graphical window system. Microsoft was very far away from that. I was amazed at what the system could do at that time, after being in development only for a year or so (and of course running many programs that already were written for Unix).

    I ran a phone BBS, a packet radio system (with Z8530 SCC card), and the usual software all on the same system and without spending whole days on managing HIMEM space and debugging nasty crashes due to memory overwriting.

    So for me, Linux is just the natural system to run on my PC and Windows is only an alternative that came later. Of course I had a lot to do with Windows at work but that did not make me want to run it at home.

    When VMware came out (first version), I was very enthusiastic and bought a license and ran some Windows versions as VM (Windows NT4, 95, 2000, XP), mainly for experiments and to run some software only available for Windows.

    However that became less practical once Windows was past XP due to its resource usage on my machine. Today I still use VMware ESXi on server machines both at work and in the amateur network AMPRnet/HAMNET. Our systems on that network are almost all Linux with only an occasional Windows machine for backward things like YAESU Wires-X.

    Of course today Windows is much more stable than when it all started, and you can do a lot of useful things with it. However, now that locally installed software becomes less important and more environments are moving to cloud services with web browsers as the user interface, Linux is becoming more popular again.

    (and of course most people have several Linux systems even when they do not know that...)

  • Hello,

    For me the most stable and reliable SDR software so far has been HDSDR. It also supports a large selection of SDR hardware via its extio dll interface. As I use USRP N210 in some applications I had to modify the extio to support external 10 MHz reference. Also for LEO satellite tracking I added TLE based doppler compensation in the extio interface. For EME work I use spectravue with SDR-IQ. At home I also run Ubuntu linux as VM under vmware player. Just built gqrx from source with a small modification to enable external reference for USRP. Under linux gqrx runs stable, no crashes observed so far. Using it also for Es'hail-2 beacon reception. I have tested bandwidths up to 5 MHz with FFT sizes up to 262144 without major problems. The only problem I see is related with intermittent audio buffering problem in the version compiled from source while the version distributed as binary package don't seem to have such problem. It could be related to the latest QT5 version used to bulid the software.


    Viljo ES5PC

  • I've been experimenting today with an RSP1A as IF for an unmodified Octagon LNB.

    SDR software is HDSDR and I have that working well in conjunction with WSJT-X v2 so that WSJT-X controls the frequency of HDSDR via virtual serial connection. Audio is connected from HDSDR to WSJT-X using virtual audio cable.

    Receiving both 10705 and 11205 beacons well and audio sounds perfectly good enough for SSB. Some drift that could be accommodated with the occasional retune.

    For digital work it will be necessary to lock the Octagon (apart from JT65C which will probably cope with the drift).

    73 Charlie G3WDG

  • Charlie wait for changing weather conditions , and fast temperature changes.

    If the sun comes out behind clouds the LO freq will change rapidly.

    You will clearly see that the drift will be too fast to tune manually.

    I'm already tired to explain that again and again, so this was the last time.

    So long... 73 DB8TF

  • Thanks - you clearly have lots more experience with Octagons than I do I have only owned one since today!

    I have no plans to use it on the transponder - I have a fully GPS locked system ready for that, but it is unable to tune to the existing beacons owing to filters in the downconverter and preamps.



  • Charlie wait for changing weather conditions , and fast temperature changes.

    If the sun comes out behind clouds the LO freq will change rapidly.

    You will clearly see that the drift will be too fast to tune manually.

    I'm already tired to explain that again and again, so this was the last time.

    and this is the wrong threat anyway ;-)

    But the good news is, after installing the latest SDR# version V1.0.0.1700 it seems not crashing that often anymore.. but will wait for my other 0.5ppm RTL-SDR's to arrive and put them on my Raspberry Pi where I currently have my Funcube Dongle..

    BTW: We had a lot of changing weather yesterday and today, but I found the stability of my unmodified OSLO good enough for SSB. Do you know how much you have to tune due to Doppler on linear transponder on a LEO? So I have no panic ;-) I only noticed that the very strong wind at some stage made some heavy wobbling of the frequency due to mechanical vibration..

    Peter Gülzow | DB2OS | AMSAT-DL President | member since 1983 | JO42VG

  • Never had contact with GHZ Receiving i took the chance to figure out how it works with Low-Budget Stuff.

    Installed a 60cm Offset Dish with an unmodified Octagon TWIN LNB connecting via a 12V Bias to a NooElec SDR Stick i can receive the 10706 EB Beacon with GQRX on RPI3 whitch is also my 1st experience in using a "LINUX-System". Not very difficult due to get a couple of Information out of the internet.

    Lokking forward to get the Signals from the Amateur Radio Beacon hopefully the next few weeks.



    dl4sdr>qth JN49 Square

  • my "experimental" solution for NB uplink...

    SDR TX with LIME SDR (at first with max 10W out @ 60cm PF DISH) ....using some more gain after the LIMESDR and an narrowband TX FILTER @ 2.4G

    Info about the video:

    TX: Odroid XU4Q, Ubuntu Mate 18.04, Gnuradio 3.7.11, gr-limesdr, test-tx flowgraph by dg0opk capture via VNC REMOTE

    RX (monitor):
    MiniPC I7-7700T, Ubuntu 16.04, Adalm-Pluto, GQRX TX frequency: 2402MHz

    used modes in the video:

    -USB(liveaudio from soundcard with mic connected) delay around 0.5s
    -AUDIOLOOP (from WAV file)
    -PSK(LOOP), CW(LOOP), NOISE, 1KHZ SINE --- from gnuradio flowgraph
    other modes are possible :
    -WSJT,WSJTx (..FT8,JT65,JT9....) or FLDIGI via virtual audio (pulseaudio server) installed on the ODROID XU4

    IMPORTANT NOTE: ... this was a first test ......


    73 de dg0opk