IS0GRB Winlink Server on QO-100 (Dial 10489635.0 USB)

  • Good morning, taking as reference a future trip of my friend IS0EZZ solitary navigator, i activated in test the IS0GRB winlink server on QO-100, Dial frequency 10489635 USB

    It would be interesting to be able to carry out tests for sending and receiving emails, useful for those traveling by mobile, in caravan or in navigation where internet is not accessible. All modes are supported, Winmor, Ardop and VARA modes for high-speed file transfers

    The system is managed by GPS-DO, both in reception and in transmission

    The server is also listed on the winlink site, but since it is not possible to enter the frequency in full MHz i had to insert it in Khz; i entered the QO-100 references in the description

    Reports and opinions are welcome


    Roberto IS0GRB

  • Some infos:

    Dial RX Downlink 10489.635 MHz USB (739.635 LNB converted) / Dial TX Uplink 2400.135 MHz USB

    In RX you can use 40 ,60, 80cm Dish antenna + Universal LNB sending 13V power supply (vertical polarization) + SDR interface R820T2 + SDR-Console program + Virtual CAB audio driver (, to send received audio from the SDR to the Virtual Cable Recording interface for Winlink Express program (

    In RX you can use also the QO-100 websdr + Virtual Cab driver

    In TX you can use 432 MHz to 2400 MHz converter / transverter, example Transverter from SG-Labs 2W power + Dish feed RHCP short Helix antenna with 3-4 coils or Wi-Fi patch 7-8dB horizontal polarization and 60, 80, 100 cm Dish antenna or only long Helix antenna with 30-40 coils without dish.

    If you are in car, caravan or boat i can suggest to use a simple 40cm parabolic Dish in RX that have a wider reception lobe and avoid some problems during movement and a long Helix or 60, 80cm parabolic Dish in TX.

    You can use a simple SAT 2 way splitter to send 13V to LNB from a power supply and at the same time to extract RX signal converted from the LNB for SDR interface in 739MHz (739.550 - 739.800 NB SAT transponder).

    To setup the antenna to the maximum signal please refer to the 10706 MHz beacon (GPS locked) of the Geo SAT to 26 Est which is converted in 956 MHz received with a normal SDR interface.

    Other info how to receive the SAT in others sections of this forum and IS0GRB WebSDR (…est_dial_10489635_mhz_usb

    I will try to prepare a schematic and guide for use


    Roberto IS0GRB

  • Hello Roberto,

    excellent idea (I was expecting this to happen some day, hi hi).

    Is your server now running 24/7 ?

    I just tried to connect several times using RMS Express with Winmor modem to your server and there was no reply. (I was "spot on" on TX and RX with my GPSDO reference)

    On HF the software works very well. My signal sounded OK on the downlink and my signal should have been sufficiently strong (close to upper PSK beacon level).

    Or was your server just down?

    I tried both .635 and .600 (because on the Winlink list your server is listed as 10498.600 - not .635). But no luck.

    73 de Oscar DJ0MY

  • Good morning Oscar and thanks for your report, i confirm that the server is active

    I verified the system and seems to be OK, active h24 and monitored

    Can you try again? if you have other problems, please write me an email, we will see together what it is

    Many thanks


    Roberto IS0GRB

  • Hello Oscar, i' m viewing your connection request

    Unfortunately the delays due to the satellite are excessive and when my system responds to you, yours is already retransmitting and clearly colliding.

    The winmor provides a maximum delay of 280ms, if I remember correctly, I would ask you if you could try with ardop and vara. If you are using sdrconsole please try to reduce the buffer in receive > options set Default instead X2 o r X4


    Roberto IS0GRB

  • Oscar, the solution to this problem could be to operate in split even if it seems to me that winmor does not foresee it, you should try to connect in ardop mode or with Vara modem that manage delays better

    After you have performed the tests with the other modes we can try in split


    Roberto IS0GRB

  • To reduce delays it is necessary for at least one of us to have the reception converted to analogue, I am currently using sdr which generates 130ms of delay, added to the uhf radio switching delay and the satellite delay, we are not there . it is useful to have the direct conversion of the lnb to 432 MHz in analog to reduce a third of the delay but at the moment I can't do it, I should make changes to the system, I think later. but we can also try in ardop and vara mode, thanks anyway for your tests


    Roberto IS0GRB

  • Roberto, it seems indeed that the ARQ timing of all those modes is not suitable.

    Aven ARDOP whcih has built in latency ARQ timing negotiation is not able to cope with this long latencies.

    My last attempts were actually with fully analog TX and RX !

    Going fully to analog I could hear the start of your reply e.g. in ARDOP mode, but the modem already started transmitting next packet while you were transmittting the connect acknoledgement.

    Sorry, but it seems that all three modes are ARQ timing wise not suitable for QO100.

    Or perhaps both sides need to move to to fully analog radio to improve latency even more.

    Testing split mode does not really help because all three modems (Winmor, ARDOP and VARA) do not seem to support full duplex links. They switch off the RX decoder during transmission.

    Maybe we need to talk to one of the modem authors to introduce a special long ARQ delay version for QO-100 and SDR use?

    Sorry for the negative testing results...

    73, Oscar DJ0MY

  • Ok Oscar and many thanks for the report and patience.

    I have seen that the only way that works well is Ardop, try to sets the leader lenght at 120ms and we try again, otherwise I will necessarily have to receive analogue to try new tests.

    I disabled vara because it loops


    Roberto IS0GRB

  • Good morning Oscar, i checked the .ini files of Winmor and Ardop modem in the C:\RMS directory and you can modify the delays.

    Specifically, in Winmor tries to set these parameters in the WINMOR_TNC.ini file:

    ResponseDelay = 1000 (instead of 300)

    LeaderExtension = 10 (instead of 0)

    Some tests with these parameters have already been successfully carried out, view this link:

    As regards Ardop modem in the file ARDOP_WinTNC.ini or through the GUI in the Ardop modem TNC setup, try to set these parameters:

    LeaderLenght = 500 (instead of 160)

    Trailer Length = 10 (instead of 0)

    I also changed these parameters in my server as indicated, i believe that in this way, considering the delays, the connection can succeed.

    Interesting document on the functioning of Winlink and RMS Express:…s.3-WINLINK-in-EMCOMM.pdf

    The server is always operational in testing until new communication.

    If any other colleague wants to try I will be grateful if he can do tests.

    73 de Roberto IS0GRB

  • Hi Roberto,

    I will try to change the parameters in the INI and try to connect your server tonight.

    I think the delay with Winmore mode could work.

    I am not sure if ARDOP would work, because my understanding is that leader length is only the initial tone market before the synschronization starts and the data is sent?

    I think this should not have an influence on the delay between one ARQ burst and the next? (or maybe I do not fully understand the protocl, hi hi)

    Hope to have success later.

    73 de Oscar DJ0MY

  • Roberto,

    my WINMORE.INI did not have those two parameters, so i added them manually.

    I am therefore not sure if they are really understood and applied by the Winmore TNC modem software.

    I tried with analog receiver (like last attempt yesterday) and with 1000 / 10 and 2000 / 10, but I hear no difference in my transmission.

    It sounds as if the break time between two connect packets is always the same default matter what I set in the INI.

    One time (first try) the connection with your server suddenly happened, but then your server was sending packets to me with too short intervals and my TX was never keying PTT (maybe because the break inbetween was too short and the modem was detecting that the frequency was busy) or only after many retries from your server my TX was ocasionally keying.

    So either still the parameters are not right or the software ignores them because they are too long?

    Hmmm, not sure what else to try....

    73, Oscar DJ0MY

  • Dear Oscar, in the meantime I thank you for the availability and the tests carried out, they were very interesting and allowed to bring out some critical points of this system through the satellite.

    I will write to the developers of Winlink to propose an implementation of the delay parameters so that it can also be used via QO-100, which will allow communication via e-mail in a long distance, where internet is not available and in emergency communications.

    I undertake to carry out further tests with another uplink in order to be able to modify parameters without the aid of a friendly station.

    Unfortunately, at the time I did not receive the availability of other stations to carry out further tests.

    There are other ways of this system that we can try in AFSK and which will be subject to further tests if you are available.

    I would also like to thank Peter DB2OS who wrote to me via email and supported my idea of testing this system, very useful in faraway places and in emergency situations.

    See you soon


    Roberto IS0GRB

  • Hi Oscar, i sent an email to Steve K4CJX, Winlink administrator, explaining the problems and if they can give us support in the next winlink software release for the tests of Winlink via satellite.
    I sent him the links of this forum so he could read the problems encountered

    We await for an answer


    Roberto IS0GRB

  • Oscar and all, Steve K4CJX, very kind person, replied which has immediately contacted the author of Winmor and Ardop and that he will answer me directly.

    I also contacted EA5HVK the author of the Vara modem.

    We await their support


    Roberto IS0GRB