NB Transponder Bandplan and Operating Guidelines

  • It's not only the required bandwidth for the beacon but also a guard band to prevent interference of other uplink signals with the beacon. And last but not least, the beacon should serve as a guide rail for the users to keep clear of the transponder limits.


    Look at it as a guide rail on a highway: in theory you can drive really close to it but in practice it is recommended to have keep a certain distance.


    Anyways: It is expected that the document will be updated regularly to take into account the operational experience.

  • Which digital modes will match the bandplan for digital modes ?

    There is no restriction on the actual mode used, but the transmitted or occupied bandwidth shall be below 2700 Hz.



    2400,100 – 2400,120 10489,600 – 10489,620 20 narrowband digimodes (500 Hz max. BW)


    and



    2400,120 – 2400,140 10489,620 – 10489,640 20 digimodes (2700 Hz max. BW)

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • Are there any restrictions on the experimental section? E.g. bandwidth, signal level, length of transmission? I realise it is only 5kHz wide but we can't all use all of it all of the time - or maybe we can with some modes.

  • Do I interprete it right, that in the mixed mode segment 2700Hz BW limitation is suggested for "normal mixed modes", but that this does not apply for the "special purpose" use, as nothing is mentioned ?


    The only remaining question would be, what qualifies for "special purpose"....? And should this be done in agreement with AMSAT?


    Oscar

  • @AMSAT: thanks a lot for the extended transponder bandwidth and the updated bandplan!


    I have two questions, just for my orientation:


    • which one of the CW tones is the actual nominal beacon frequency? Is it the lower tone on 10.489.500 MHz and the upper one on the 10.490.000 MHz?
    • how accurate are these frequencies from Bochum? Can they actually be used for calibration?



    Thanks, vy 73


    Holger 'Geri', DK8KW

  • Some Q&A:


    • which one of the CW tones is the actual nominal beacon frequency? Is it the lower tone on 10.489.500 MHz and the upper one on the 10.490.000 MHz?
    • how accurate are these frequencies from Bochum? Can they actually be used for calibration?

    All Beacons, LEILA and Up-/Down-Converters are stabilized by an high precision GPS locked Rubidium 10 MHz reference oscillator:

    • 10 MHz Rb-Normal, HP Z3801 (GPS-locked)
    • Allan-Deviation ca. 1E-11 (tau=100 sec)
    • complete RX & TX chain phase locked


    Lower Beacon (CW) is on 10.489.500 MHz, Middle Beacon (PSK) on 10.489.750 MHz, Upper Beacon (CW&Experimental) on 10.490.000 MHz


    Some small offsets might be possible, and also due the Transponder itself.


    The new Beacon/LEILA hardware in Bochum is now based on ADALM-PLUTO.

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • more Q&A:

    Are there any restrictions on the experimental section? E.g. bandwidth, signal level, length of transmission? I realise it is only 5kHz wide but we can't all use all of it all of the time - or maybe we can with some modes.


    There seems to be a misunderstanding:

    The "EXP Beacon" is now introduced as the former "Upper Beacon", as the old PSK-Beacon is now the Middle Beacon ;-)

    This section has to be cleared from any use or interference: including Guard bands like the other beacons.

    Mixed Modes (10.489,850 to 10.489,995 MHz)

    The mixed mode section moved completely to the new area at the upper end of the transponder, just above the SSB-Only section.

    Indeed the Mixed-Mode is fully available to all users, including SSB :-)

    The additional term "special purpose" means, that some frequency might be reserved for other purposes later. Those will also be marked in the bandplan.. As of today (Feb. 15th) there are now restrictions other than the maximum 2.7kHz BW.


    Do I interprete it right, that in the mixed mode segment 2700Hz BW limitation is suggested for "normal mixed modes", but that this does not apply for the "special purpose" use, as nothing is mentioned ?


    There is no change on the maximum allowed bandwidth of 2.7 kHz modulation. This limitation is still valid for the whole NB transponder without any exception, including special purposes (see also on our webpage as mentioned above).


    "Special purposed" is meant for disaster communication and other activities we are reviewing at the moment, including call-in channels etc.. nothing specific defined yet ;-)

    We were planning to have the FUNcube telemetry 1K2 PSK beacon from Antarctica (DP0GVN) there, but this project has to be delayed until next year.


    The only remaining question would be, what qualifies for "special purpose"....? And should this be done in agreement with AMSAT?

    As usual, any automatic or unattended operation requires a special license from the local licensing authorities and must be coordinated with the operator beforehand. This task is performed by AMSAT-DL on behalf of QARS and Es'hailSat.

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • f5uii Thanks Christian!


    SDRConsole New BandMap QO100 by F5UII

    In SDR Console (from version 3.0.11), on the View tab, click on Markers. On the Spectrum Makers window, click on the “…” button and choose CSV Import. Point to the download file, select all lines and OK. Close the “Spectrum Makers” window.

    If you already have existing markers, delete them beforehand.

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG

  • Ah - So you mean this beacon is from AMSAT, not an allocation to put beacons in. I miss-understood. Lets hope it is something more interesting that 400 baud BPSK.


    It is a pity we can't accommodate signals that are a little more than 2.7 kHz wide but I guess the transponder is short on bandwidth and there are rarely gaps between QSOs.


    With my deaf Pluto the transponder noise floor is reduced, but it's also not flat. This is nothing new but if you have a weaker station keep away from the edge, you might fall off.

  • Ah - So you mean this beacon is from AMSAT, not an allocation to put beacons in. I miss-understood. Lets hope it is something more interesting that 400 baud BPSK.

    Yes, as mentioned in the article New QO-100 band plan there are plans to have some sophisticated modulation and coding on it, to allow extreme weak signal reception. For example just with a handheld LNB.. maybe DXCluster information, kind of SMS service, etc..

    Mario DL5MLO is working on this stuff...

    Peter Gülzow | DB2OS | AMSAT-DL member since 1983 | JO42VG