Posts by DB2OS

    LoRA - APRS via QO-100 talk from OE3DMB at HAM RADIOnline 2020




    Andreas OE3DMB , thanks for this very nice presentation!


    just some small remarks:


    - After extensive discussions with our counterparts in DARC and others, we came to the conclusion that -as things stay today- LoRA would be legal in Germany (see also earlier message in this thread).


    - Use of LoRA on the WB Transponder:


    Indeed we want to encourage development of new technologies on the QO-100 transponders as long as they fit to some basic requirements.

    • Experiments using unusual modes (for example ranging or LoRa) should use the lower 1.5 MHz of the “Wide and Narrow DATV” Segment. See also https://wiki.batc.org.uk/image…-100_WB_Bandplan_V2.0.pdf
    • Due to the very large number of potential users, all transmitting stations should monitor the wideband spectrum monitor and the co-ordination chat window that has been established by AMSAT-DL and the BATC at https://eshail.batc.org.uk/wb/


    Again, thanks for your achievements and first demonstration of LoRa via QO-100


    73s Peter DB2OS

    Gibt es im shop.amsat-dl.org kein Sendungverfolgung Informationen :/?


    Hallo Frank und alle,


    der Versand erfolgt manuell und daher können die Tracking-Informationen nicht automatisch in das Shop-System übernommen werden. Da das Versand-Team dies ehrenamtlich macht, wäre der zeitliche Aufwand einfach zu groß.


    "Abgeschlossen" bedeutet, dass die Bestellung abgeschickt bzw. DHL übergeben wurde.


    Sollte nach frühestens 14 Tagen nichts angekommen sein, dann bitte über den Shop-Kontakt nachfragen.

    Michael wird dann entsprechende Nachverfolgung/Nachforschung bei DHL vornehmen..


    Sorry, aber leider momentan für uns nicht anders machbar..


    73s Peter

    Hi Bert,


    I use Airspy R2 SDR, SSB SP-200 Preamp and ANjo Eggbeater.


    It's only a very simple setup at the moment to run the SatNogs software, but it works very well to see what's going on in the 2m satellite band.


    73s Peter

    Good News from CAS-6


    Hello,

    The CAS-6 V/UHF antenna has been deployed today. Due to some OBC failures, CW beacon and GMSK telemetry are not working properly. At present, only the carriers are transmitted on the two frequencies, the linear transponder has been put into operation. We will then try to diagnose and then determine whether the CW and telemetry data stream transmission can be recovered.


    ● CW Telemetry Beacon: 145.910MHz

    ● AX.25 4.8kbps GMSK Telemetry: 145.890MHz

    ● U/V Linear Transponder Downlink: 145.925MHz, 20kHz bandwidth, Inverted

    ● U/V Linear Transponder Uplink: 435.280MHz


    TLE:

    CAS-6(2019-093C)

    1 44881U 19093C 20170.81187924 -.00001118 00000-0 -13581-3 0 9991

    2 44881 97.9575 246.8556 0015830 36.2280 323.9959 14.81412013 26893

    73!

    Alan Kung, BA1DU

    And yes, I know full-duplex is a golden rule (but also read that it is mostly for LEO's and it might not apply for QO-100 that strictly...)


    I don't know where you heard that..


    The official transponder bandplan and guideline says:

    "Full-Duplex operation is mandatory (you must be able to monitor your own downlink while transmitting!)"


    I know that some people ignore it or will start to argue, but that doesn't make it better ;-)

    And depending on the WebSDR is also somehow cheating and not state of the art...


    You could still use your IC7300 for RX and IC7000 for TX, it's not so difficult to calculate and tune manually.. many people are just doing that..


    Alternatively you could simply use SDR-Console, an cheap RTL-SDR dongle for RX and let SDR-Console tune your IC7000 via CAT-Interface...


    73s Peter

    Hi Robert,


    Welcome on-board!


    Sorry for asking, but does IC7000 not allows continous receiving on HF while transmitting on 2m/70cm?


    Or you use the IC7300 for RX (28 MHz for example) and the IC7000 for 70cm TX ?

    If both transceivers have remote control, even synchronizing them would be no problem...


    73s Peter

    As I know UO-11 is sending his telemetry 10 days with a pause of 10 days and this cycle begins again.

    Yes, every 20 days UO-11 comes allive..

    All the analog telemetry channels are gone, probably due to a failure of the ADC.


    more here:

    http://www.users.zetnet.co.uk/clivew/u2rpt.htm


    Clive Wallis, G3CWV passed away on 27th March 2015.


    Be carefull, his "new web site" is pointing to a domain grabber with odd contents.

    Hope someone archives his old pages berfore they are deleted...

    ARISS Contact is Scheduled for I.E.S. Pedro de Valdivia in Villanueva de la Serena, Spain


    June 12, 2020—Amateur Radio on the International Space Station (ARISS) has received schedule confirmation for another social-distanced ARISS radio contact with astronauts. ARISS is the group that puts together special amateur radio contacts between students around the globe and astronauts with ham radio licenses on the International Space Station (ISS).


    This radio contact will be a Multipoint Telebridge Contact via Amateur Radio, developed for distance learning while worldwide education institutions are closed due to COVID-19. ISS Commander Chris Cassidy, amateur radio call sign KF5KDR, will support the ARISS radio contact.


    The ARISS telebridge radio ground station--a ham radio satellite station with special equipment for teleconferencing--will be operated by ARISS team member Jan Poppeliers, using amateur radio call sign ON4ISS, who will be social distanced at an AMSAT Belgium club station in Aartselaar. Cassidy will be at the ARISS ham radio station on the ISS and each youth will tie in from home via their telephones. Students take turns asking Cassidy their questions. School staff and the public can watch the livestreamed action from their own homes.


    The youth taking part in this ARISS contact are from I.E.S. Pedro de Valdivia in Villanueva de la Serena, Spain. The radio contact is scheduled for June 16, 2020 at 14:25 local time in Spain (8:25 EDT, 7:25 CDT, 6:25 MDT, 5:25 PDT, 12:25 UTC). Prior to COVID-19, the students had studied and observed ISS passes, participated in NASA's EarthKam program, and built communication equipment to listen to ARISS contacts and make ARISS APRS contacts, and downloaded ARISS SSTV images from the ISS. The teacher said, “Our school emphasizes languages and cultures and gives special importance to science and technology.”


    ARISS invites the public to view the livestream of the ARISS radio contact at: https://youtu.be/PyNqsTMqAoQ.


    As time allows, students will ask these questions:


    1. Due to Covid-19 we have to stay at home. Do you have any advice for us?

    2. Do you think the Astrobee robot is the beginning of a new generation of robots that would work in the ISS?

    3. Does weightlessness affect your thinking?

    4. How do you keep fit if you are at zero gravity?

    5. What do you do to entertain yourselves in the ISS?

    6. After living in space, have you gained a new perspective on life and our everyday problems?

    7. Did you feel sick while you were in the rocket?

    8. What inspired you the most to become an astronaut?

    9. What is the basis for your diet?

    10. What would happen if you cried in space? How would tears react?

    11. Is your spacesuit comfortable?




    Dave Jordan, AA4KN

    aa4kn@amsat.org      


    Like us on Facebook, follow us on Twitter – search on Amateur Radio On The ISS and @ARISS_status.                                                                              

    Here are all the UoSAT-1 bulletins starting with issue #10 until #109 when I stopped printing them.

    I did not had a printer before #10 :-)


    Thanks to Matthias DD1US for hosting my scans:


    UoSAT-1 bulletins #010 - #040 received by DB2OS

    UoSAT-1 bulletins #041 - #064 received by DB2OS

    UoSAT-1 bulletins #065 - #079 received by DB2OS

    UoSAT-1 bulletins #080 - #100 received by DB2OS

    UoSAT-1 bulletins #100 - #109 received by DB2OS


    I agree with Lucio, it was a great time when we had to send receiving reports by postal mail to Martin Sweeting and his team to the University of Surrey in Guildford.


    There was a big community eagerly waiting for a new UoSAT bulletin to be downloaded every weekend.


    Internet was not existing at that time, so it was a fantastic resource of latest information from the AMSAT and hamradio community world wide -, see yourself above.


    It's a pity that 39 years later many LEO's even don't give a glimpse of that..

    UoSAT-1 OSCAR-9 was launched in 1981.


    UoSAT-2 OSCAR-11 launched in 1984 was carrying the first Digital Communications Experiment (DCE) which allowed Store&Forward communication based on simple asynchronous communication protocols.

    I was very happy at that time to participate as one of very few UO-11 groundstations.


    The DCE was the forerunner of the PACSAT satellites using AX.25 based PACSAT Broadcast Protocol (PBP).


    I believe FalconSAT-3 launched in 2007 is the last OSCAR with a PACSAT BBS onboard.

     

    Achim DH2VA has graphically illustrated the relationship between the various dependencies and how the SNR behaves with the size of the dish or which factors dominate. The graphics are also part of our official QO-100 presentation.



    The blue curve shows that a small dish leads to considerable disadvantages, but the advantages above 1-1.5 meters are at some point only in the range below 1dB.

    Achim DH2VA hat den Zusammenhang der verschiedenen Abhängigkeiten einmal grafisch dargestellt und wie sich das SNR mit der Größe des Spiegels verhält bzw. welche Faktoren dominieren. Die Grafiken sind auch Bestandteil unser offiziellen QO-100 Präsentation...







    Die blaue Kurve zeigt, dass ein kleiner Spegel zu erheblichen Nachteilen führt, aber die Vorteile oberhalb 1-1.5 Meter irgendwann nur noch im Bereich von unter 1dB liegen....

    A dish size of 60cm-75cm is strongly recommended if you want to receive hassle free.

    A smaller dish would exceptionally for portable operation.

    But it is definetly not optimal and you may not hear weaker stations on the satellite with a smaller dish.


    Keep in mind: To be as loud as the beacon is not the goal, it is the maximum limit!


    There should always be a good balance between receive capability and transmit power.. the "alligator" phenomena..