Posts by DB2OS

  • DATV Beacon changes

    Dear All,


    over the XMAS "maintenance" period we are planing some changes on the DATV beacon to allow for more user space.



    1) new DVB-S2 parameters

    DVB-S2 QPSK; 3/4FEC; 1500kSymbole; RollOff=0,25; Pilots=off


    Thus the occupied bandwidth will reduce from ~2.5 MHz to ~1.9MHz while the picture quality should only change slightly.. 0,9dB more C/N required.


    2) Center frequency

    We will be trying to move the DATV beacon as much to the edge of the transponder as possible and useful without too much degradation. This should give us another 0.5 MHz of more room on the transponder.


    New center frequency will be published after the change..


    Currently we are planning the 25th or 26th of December to perform the changes...


    73s Peter

  • SMOG-P (MO-105) and ATL-1 (MO-106)

    On December 6, 2019, the Technical University of Budapest SMOG-P and ATL-1 PocketQubes were launched on an Electron launch vehicle from the Mahia Launch Complex in New Zealand. SMOG-P and ATL-1 were developed as part of the university curriculum and operated in cooperation with the HA5MRC Technical University amateur radio club. The satellites carry spectrum monitoring payloads and are currently active. At the request of the Technical University of Budapest, AMSAT hereby designates SMOG-P as Magyar-OSCAR 105 (MO-105), and ATL-1 as Magyar-OSCAR 106 (MO-106). We congratulate the owners and operators, thank them for their contribution to the amateur satellite community, and wish them a long mission and continued success on this and future projects. 73,Drew Glasbrenner, KO4MA, AMSAT VP Operations / OSCAR Number Administrator

    SMOG-P (MO-105)

    is a 1p PocketQube (5x5x5 cm, 250 grams), a fully redundant tiny satellite with an actual scientific payload: a flying spectrum analyzer. It measures the scattered RF energy over the UHF band (specifically, in the digital terrestrial TV band) that can be detected in space.


    ATL-1 (MO-106)

    is a larger 2p PocketQube featuring the same spectrum analyzer experiment.



    Both satellites transmit almost identical telemetry data. In addition to basic CW telemetry carrying callsign, battery voltage and temperature, there is a digital telemetry with variable data rate and coding scheme. Most frequently, modulation is 1250 or 5000 bps GMSK. The data is encoded either by the well-known "AO-40" FEC, or a shorter, proprietary variant of it, but they can also use a more powerful, state-of-art repeat-accumulate (RA) coding scheme.


    Some practical information about receiving the telemetry:


    A GUI telemetry receiver is available for Windows and Linux (soon for OS X as well), and a command line receiver can also be used (Linux only).


    Both can be downloaded from https://gnd.bme.hu:8080/index


    The programs are able to submit the received packets to the central telemetry data base. This requires a quick registration, the login credentials can be used with either of the decoders. There are some issues with the GUI software that hopefully will be resolved within a few days.


    These decoders assume either a USB receiver connected through the sound card or an rtl-sdr receiver.

    Thanks to Daniel Estevez, EA4GPZ, a high quality, full decoder and packet uploader is also available for GNU Radio 3.8 within the out-of-tree module gr-satellites. For uploading to the received packets, it uses the same login as the "official" programs do:


    https://github.com/daniestevez/gr-satellites/tree/maint-3.8


    This decoder can unleash the full potential of the RA FEC. You'll need to put an FM demodulator in front of the flowgraph.

    I'd be glad to see many submissions on the "Leaderboard" from around the world:

    https://gnd.bme.hu:8080/leaderboard

    Having many receiving stations around the globe could greatly improve the global picture the spectrum analyzer payload can offer.


    73

    Peter

    HA5CQA/AK4RP

  • PiSDR SDR Linux Distro for Raspberry Pi

    Here is a nice package of SDR tools for the Raspberry Pi from PU2SPY, Luigi Freitas.


    PiSDR Project Homepage


    with the current image the PiSDR Projects supports


    the following software is pre-installed:


    Luigi says:

    " The absolute majority of packages installed on this distro aren’t available through apt. The compilation of some of them requires hours of processing and multiple dependencies."

  • CAMSAT CAS-6 satellite

    Dear Peter,


    Thank you!

    Today CAS-6 has been successfully launched, the satellite is currently in orbit testing, the amateur radio payload is expected to be operational in about three days.


    Attached photo of CAS-6


    73!

    Alan, BA1DU

  • CAMSAT CAS-6 satellite

    The launch was successful..


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  • FLORIPASAT-1

    Together with CAS-6 there is also the Brazilian Cubesat FloripaSat 1 to be launched on 2019-12-20 at 03:21 UTC with a CZ-4B rocket from Taiyuan Space Center.


    FloripaSAT-1 has a Digpeater on-board with NGHam / AX.25 protocol.


    Info on FloripaSat 1:

    https://floripasat.ufsc.br/


    Amateur radio info:

    https://floripasat.ufsc.br/communication-info/

    http://www.amsatuk.me.uk/iaru/…_detail.php?serialnum=646


    (thanks to Nico PA0DLO for Information)


    Software for Linux (including source code) can be downloaded here: https://github.com/floripasat/grs/wiki

  • CAMSAT CAS-6 satellite

    CAMSAT CAS-6 Satellite will be Launched soon successfully launched!

    CAMSAT's amateur radio payload CAS-6 piggybacked on a technology test satellite TIANQIN-1 will be launched at 3:21 UTC on December 20, 2019 at the Taiyuan Satellite Launch Center of China using a CZ-4B launch vehicle. The primary payload of this launch is China-Brazil Earth Resources Satellite CBERS-4A.



    CAMSAT News Release for CAS-6 Satellie.pdf


    CAS-6 Satellites Digital Telemetry Description.pdf


    CAS-6 CW Telemetry Encoding Format.pdf


    Orbit type : SSO

    Apogee : 629km

    Inclination : 97.89˚

    Period : 97min


    Call sign: BJ1SO


    VHF Antenna: one 1/4λ monopole antenna

    UHF Antenna: one 1/4λ monopole antenna


    CW Telemetry Beacon: 145.910MHz 17dBm

    AX.25 4.8k Baud GMSK Telemetry: 145.890MHz 20dBm

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

    U/V Linear Transponder Uplink: 435.280MHz

  • QO-100 und Klasse E Lizenz

    Auch wenn in der offiziellen Mitteilung nur von HamNet die Rede ist, ist dies auch ein kleines Weihnachtsgeschenk und wichtige Nachricht für Inhaber der Klasse E-Lizenz. Diese können somit weiterhin über den QO-100 Satelliten funken. Mit der maximal zulässigen Leistung von 5W PEP auch problemlos möglich, wenn die PA direkt an der Antenne ist..


    Quote

    Nutzung der Frequenzbereiche 2320–2450 MHz und 5650–5850 MHz durch Inhaber einer Zulassung zur Teilnahme am Amateurfunkdienst der Klasse E.

    Kurz vor Jahresende hat die Bundesnetzagentur mit der Amtsblattmitteilung Nr. 666/2019 die geschaffene Regelung des Zugangs für Inhaber einer Zulassung der Klasse E zum 13-cm- und 6-cm-Band bis zum 31. Dezember 2020 verlängert.


    Nutzungsbestimmungen

    Die maximal zulässige Sendeleistung bei der Nutzung der Frequenzbereiche 2320 – 2450 MHz und 5650 – 5850 MHz durch Inhaber einer Zulassung zur Teilnahme am Amateurfunkdienst der Klasse E beträgt 5 Watt PEP.

  • NB passband monitoring

    Hi Roland,


    I observed it some days ago too and believe it's somehow related to the periodic radar noise/sweep.


    Interestingly, someone made a Doppler curve from a large Meteor last night.. It was obviously de-fragmenting in different directions, that's why there are several curves than with different Doppler... Looks somehow similar, but maybe just an coincidence...

    So maybe the spurs are something reflecting off the radar on the NB ?


    .

  • AMSAT-DL Sende- und Empfangsmischer für QO-100 (P4-A)

    IK1IYU Well, it was already sent out.. but unfortunately delivery to Italy and Spain often takes much longer than what would to be expected. In several cases the goods were even returned after 6 weeks for unknown reasons and needed to be sent again... let's hope it will arrive soon, or that "teleportation" will be possible one day ;)

  • OPS-SAT: ESA is calling radio amateurs for help

    Calling radio amateurs: help find OPS-SAT!


    Calling all radio amateurs! ESA is challenging anyone with amateur radio equipment to catch the first signals from OPS-SAT, ESA’s brand new space software laboratory.


    On 17 December, OPS-SAT will be launched into low-Earth orbit on a Soyuz rocket from Kourou, French Guiana, together with ESA’s Cheops exoplanet-tracker.


    ESA article here: http://www.esa.int/Enabling_Su…mateurs_help_find_OPS-SAT


    gnuradio code here: https://github.com/esa/gr-opssat


    OPS-SAT completed IARU Sat Coordinator frequency coordination in October 2015.