UL/DL Frequency synchronisation GQRX with FT-817 CAT control on Linux

  • Hi there,


    has anybody successfully managed to synchronise the UL and DL frequencies of a RTS-SDR and a FT-817 with Hamlib on Linux?

    On the RX side with my RTL-SDR, I can use GQRX or CubicSDR which are both fine.


    It gets tricky when I try to hook the software up with my FT-817 CAT control:

    In GQRX, there are some python scripts available which are supposed to link GQRX with hamlib. I did not manage to install them on my machine running Kubuntu 20.04, since they require an older version of QT.


    CubicSDR also looks quite nice and it has some TRX control functions included. However, they seem to be made to use CubicSDR for a panadapter with a TRX. Proper documentation does not seem to exist, and when playing a bit with the respective functions, I did not manage to set my TX frequency on 70cm to anything without CubicSDR setting the same 70cm frequency on the RTLSDR-stick :(


    Has anybody got an idea how to approach this subject with either GQRX or CubicSDR??


    73 Jens HB9EKO

  • Hallo Jens,


    in Heft 12/19 der Zeitschrift "Funkamateur" ist genau dieses Problem behandelt worden von DG7BBP unter dem Titel "Sende-Empfangs-Synchronisierung per Software beim QO-100-Betrieb".


    Dieses Lösung läuft bei mir auf einem RaspberryPi 3 stabil.


    vy73 de Hermann-Josef

  • Hi there,


    thank you for your replies / Danke für Eure Antworten.


    It looks to me like there is no "out of the box" solution for my specific setup, but I got some good inputs that might help me to get towards what I'm looking for, provided I find the time.


    Es schaut so aus, als ob es keine fertige Lösung für mein spezielles Setup gäbe, aber mit Euren Hinweisen habe ich ein paar gute Ansatzpunkte wie ich weitermachen kann, wenn ich die nötige Zeit dafür finde.


    Not really adressing your questions, but i wrote some small Python program to 'organise' the CAT control of the FT-817. See https://github.com/pa3ang/QO-1…ster/qo-100-controller.py for more info.


    Maybe this helps you in some direction.


    vy 73 de Johan, PA3ANG

    Hi Johan,

    This looks similar to what I'm looking for, I would have to modify this script to read the RX frequency from GQRX rather than a FT-817.

    I have limited programming skills, since I wrote my last programs decades ago in Turbo Pascal. In the "External applications" section of https://gqrx.dk, I found some tools like gqrx-hamlib that also go into that direction, however I failed to get it running on my machine so far.
    Maybe it's a sign that I should invest the time and learn some python and/or go deeper into details with my Linux setup? :/



    in Heft 12/19 der Zeitschrift "Funkamateur" ist genau dieses Problem behandelt worden von DG7BBP unter dem Titel "Sende-Empfangs-Synchronisierung per Software beim QO-100-Betrieb".


    Dieses Lösung läuft bei mir auf einem RaspberryPi 3 stabil.


    vy73 de Hermann-Josef

    Hallo Hermann,

    kannst Du mir ein paar Details nennen? Setzt diese Lösung ebenfalls einen RTL-SDR Stick für den DL und einen externen TRX für den UL voraus? Wenn ich damit weiter komme würde ich das Heft bestellen.



    Maybe this will work for you: SAT Controller SDR Nano


    Hi Frank,

    I am sure it would work, but since my PC in the shack is already connected to the FT-817 and gqrx is perfectly working, I would like to avoid setting up a separate hardware only for SAT control.

    I would appreciate if I could use the software/sourcecode. However, reading other related threads in this forum, I understand that Satcontrol is only available as a RasPI image and not generically for installation on any Linux machine. You certainly have your reasons for distributing the solution only in this way.



    Thanks for all the hints, I will update this thread when I make some progress. / Danke für all die Hinweise, ich werde diesen Thread aktualisieren, wenn ich Fortschritte mache.


    73 Jens HB9EKO

    • Official Post

    Hi Jens,


    maybe this is could also be somehow helpful for you: https://github.com/ok1cdj/FT817-satmode

    Indeed not for the beacon synchronization, but perhaps for the CAT control..

    FT817-satmode

    SAT mode emulation for 2x FT817 and Arduino NANO

    Uses modified FT817 CAT library

    2 SW serials are set to 9600, HW serial is free for easy debug

    Short press off button enable / disable tracking

    Long press invert mode

    Master radio - 2 RX, 3 TX

    Slave radio - 4 RX, 5 TX

    Button is connected to PIN 6

  • I am sure it would work, but since my PC in the shack is already connected to the FT-817 and gqrx is perfectly working, I would like to avoid setting up a separate hardware only for SAT control.

    The Python program you can download here: http://www.satcontrol.de/files/satcontrol.zip


    Maybe that on your system some additional packages need to be installed. On the complete Raspberry image everything is already prepared.

  • Hallo Jens, ergänzende Informationen:

    • Für den DL wird ein rtl-Dongle verwendet; ich verwende einen mit TXCO.
    • Für den UL wird über einen USB/Seriell-Wandler ein geeigneter Transceiver angesteuert. Einzige Bedingung: der Transceiver muß in dem Programm rigctld (aus der Hamlib) gelistet sein. Ich verwende einen FT-817 oder einen IC-821.
    • Das ganze läuft auf einem RaspberryPi 3.

    Weitere Detailfragen am besten per E-Mail an db1pa@darc.de


    vy73 de Hermann-Josef

  • The Python program you can download here: http://www.satcontrol.de/files/satcontrol.zip


    Maybe that on your system some additional packages need to be installed. On the complete Raspberry image everything is already prepared.

    Thanks a lot, I will give it a try



    Hallo Jens, ergänzende Informationen:

    • Für den DL wird ein rtl-Dongle verwendet; ich verwende einen mit TXCO.
    • Für den UL wird über einen USB/Seriell-Wandler ein geeigneter Transceiver angesteuert. Einzige Bedingung: der Transceiver muß in dem Programm rigctld (aus der Hamlib) gelistet sein.

    Besten Dank, dann weiss ich, dass sich bei Bedarf eine Heftbestellung lohnt.


    Now I just have to find the time to continue .... / Jetzt muss ich nur noch die Zeit finden, weiter daran zu arbeiten....



    73 Jens HB9EKO

  • Hi,


    as promised, I would like to provide an update:


    Now I just have to find the time to continue .... / Jetzt muss ich nur noch die Zeit finden, weiter daran zu arbeiten....


    i finally found some time to follow up on this subject.


    In a first attempt, I tried to run Satcontrol on my Shack PC instead of a Raspberry Pi. Unfortunately, I did not manage to run it on my Kubuntu 20.04. Python 2 is not available by default for this Distri, and my attempts to install Python 2 with instructions from the web did not result in Satcontrol and Python 2 cooperating with each other. Porting it from Python 2 to Python 3 turned out to be something major, so I put this on hold for the moment.


    I spent a rainy weekend learning some python basics and understanding how I could code what I want, but then I realized it will take me much more time to learn how to use libraries to create a GUI for the programme and hamlib to read and write the frequencies from GQRX and the FT-817. So I put this on hold, too.


    Shortly before ordering the mentioned issue of Funkamateur, I found a tool called "QTrackUplink" : https://github.com/jbvoelker/QTrackUplink and decided to give it a try. After spending a couple of hours setting up QT Creator and understanding how to use it, I managed to compile the source code on my PC and got it working.


    This is almost what I was looking for. I can tune UL and DL with a basic offset. After that, the RX frequency in GQRX follows the TX frequency when I change it at the FT-817.


    I'm happy with this for the time being. Now GQRX as master and the FT-817 as slave for the sync is still on the wishlist. So the next step is probably understanding the code of this tool...


    73 Jens, HB9EKO

  • Now GQRX as master and the FT-817 as slave for the sync is still on the wishlist. So the next step is probably understanding the code of this tool...

    Easier than expected. I found out that without modifying anything in the code, I can simply swap the CAT information of RX and TX, as well as the start frequency entries. This makes the FT-817 follow the RX frequency of GQRX. Done some cosmetics by replacing "TX" with "Master" and "RX" with "Follower" and changed the default entries accordingly. Now the tool does what I expect it to do, The "Follower" follows the "Master" regardless what is TX and what is RX.


    73 Jens HB9EKO

  • HB9EKO

    Changed the title of the thread from “UL/DL Frequency synchronisation with FT-817 CAT control on Linux?” to “UL/DL Frequency synchronisation GQRX with FT-817 CAT control on Linux”.