Posts by DB2OS

    BlueWalker 3 (BW 3) is a ~1.5 Ton commercial satellite from AST & Science's SpaceMobile, meant for 4G/5G mobile communications constellation, is obviously transmitting in the "amateur satellite service" band on 437.500 MHz :thumbdown: for TT&C (Space-to-Earth).


    The BW3 satellite will operate under network filings made on behalf of AST with the ITU by the Papua New Guinea administration under the name MICRONSAT. --> 265582.pdf


    see also: https://db.satnogs.org/satellite/99330

    Live Stream from the Bochum WebSDR is available here:


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    Artemis-1 Launch Schedule


    Bochum visibility 2022 Sep 03 [Sat]:


    1. 18:35 - 18:47 (12 minutes, max elevation 9 deg)

    2. 20:16 - 03:10 (7 hours, max elevation 44 deg)



    The Bochum timeline (revision #2) is this:



    Sep 03 Mission

    UTC Elapsed Event

    --------------------------------------------------------------------

    18:17:00 +00h 00m 00s - Launch (nominal; window 2 hours)

    18:34:53 +00h 17m 53s - Bo AOS 1

    18:35:20 +00h 18m 20s - Orion deploys solar arrays in Earth orbit

    18:47:31 +00h 30m 31s - Bo LOS 1


    19:08:22 +00h 51m 22s - Perigee raise manoeuvre (22 second burn)

    19:55:03 +01h 38m 03s - Trans-lunar injection burn (17m59s burn)

    20:13:02 +01h 56m 02s - Burn ends


    20:16:01 +01h 59m 01s - Bo AOS 2

    20:23:10 +02h 06m 10s - Orion/ICPS separation; Bo Az/El 269/20 ***

    20:24:31 +02h 07m 31s - Upper stage separation burn

    02:13:05 +07h 56m 05s - Outbound Trajectory Correction-1 burn

    03:10:47 +08h 53m 47s - Bo LOS 2

    --------------------------------------------------------------------


    *** After Orion separates from the ICPS ("Interim Cryogenic Propulsion

    Stage"), 10 small spacecraft ("CubeSats") will be deployed to perform

    experiments and technology demonstrations. Each CubeSat provides its own

    propulsion and navigation.


    -----


    1. The above suggests that during our first visibility we see only a

    coasting Artemis-1 rocket. Maybe some telemetry, maybe S-band;

    frequency believed to be 2217 ±0.5 MHz, data rate 1 Mbps.


    2. AOS 2, our second (long) visibility, begins with the rocket in a

    trans-lunar trajectory.


    3. About 7 minutes after our AOS 2 Orion and the ICPS separate. Maybe

    some Orion telemetry, maybe S-band. 2203.2/ 2216.5/ 2287.5 MHz, ~5Mbps


    4. During the next ~90s the Cubesats are ejected. At various times

    thereafter (hours?) they will become "live". See published graphic.


    5. At this point (20:24:31 utc) some or all could be radio alive.

    We then have ~7 hours to unravel the ensuing chaos. Or sleep.


    73 de James G3RUH


    Hi Pierre,


    unfortunately we can no longer offer the V3d converter kits, everything is sold-out.

    There is a shortage on some components used and also our supplier stopped business.

    We are currently looking into alternatives and a possible new design, but it will still take a while.


    Sorry for not having better answer..


    73s Peter

    An intro video from Kurt DJ0ABR is now available on YouTube with german audio, but hopefully english subtitles will be available when YouTube created them automatically:


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    As previous year, local club F4KLK-Electrolab hosts the "AMSAT-F days" this week-end (2022, May 7-8)


    Presentations from both days will be transmitted via QO-100 with the following parameters :


    Transmission mode :

    • DVB S2,
    • FEC : 1/2
    • Format 720 p


    This is a two days live transmission on the WB-Transponder in agreement with the WB bandplan and guidelines, approved by AMSAT-DL.


    Hi,

    I have a proposal for a "new" operational mode for NB.

    The traditional QSO using USB in all frequencies is half duplex. This is due to the fact that is impossible to Rx during Tx. Using USB is possible two stations or more to talk at the same time without interfering each other.

    The proposal is that two or more stations talk together like a telephone conversation. Of course callsigns must told every few minutes according to ham radio laws.

    This will provide a more "natural" mode of communication that is impossible to implement with out QO100.


    Hi George,


    Sorry - I don't get it.. I'm confused..


    Isn't this what is already mandatory according our NB Transponder Bandplan and Guidelines which state:


    --> Full-Duplex operation is mandatory


    Thus, your equipment shall be designed for Full-Duplex, i.e. RX and TX capable at the same time,.


    Some operators do already practice that, even in larger rounds. When two people start to talk together at the same time, the other will stop or the 3rd. person will listen to both of them at the same time..


    For that reason since the launch of QO-100 we have always advocating to build or buy full-duplex equipment. Unfortunately some vendors constantly ignore this request,


    However - sometimes you also hear people talking many minutes over each other. They may not have that capability our just turned their audio down while talking, not to get confused because of the delay..


    But anyway, good that you bring up this discussion again.


    73s Peter

    There are several satellites transmitting in the 435-438 MHz amateur satellite band. Unfortunately some of them are purely commercial, which is alarming indeed.

    … good to see that at least some commercial satellite operators finally decided to be “good” and move out of the 435-438 MHz amateur satellite band ...


    This page is currently a very good resource for current status of the launched satellites:

    https://community.libre.space/…er-3-2022-01-13-15-25utc/

    The State Secretariat of Spain for Telecommunications and Digital Infrastructures has granted authorisation until 26 December 2022 to holders of amateur radio authorisations to carry out amateur service broadcasts in the 2410 MHz frequency band from 2.400,050 to 2.410 MHz, with a maximum e.i.r.p. of 1500 watts and using directional antennas with a gain of not less than 21.5 dBi, from authorised amateur radio stations located anywhere in the national territory to the QO-100 satellite located at orbital position 25.9°E of the geostationary orbit.



    https://www.ure.es/2-400-mhz-autorizacion-general-2022/

    https://www.ure.es/images/noti…/RESOLUCION-CONCESION.pdf