Demodulating the upper BPSK Beacon (AO40rcv)

  • OK, so I have been annually dusting my G3RUH 400 bit/s modem and testing my AE4EY AO40rcv SW with my library of AO-40 audio files. My favourite one is:




    Is anyone aware of any efforts in writing a suitable decoder for P4A telemetry to match the older AO-40 demodulators?

    ---

    "If you have data, you have something, if you do not, you have nothing." (Bengt Hultqvist, SK 24.02.2019)

  • James, G3RUH developed and add-on ADC for his demodulator enabling FEC decoding already in 2003.


    Back then I also used the AE4JY demodulator for FEC, but you will recognize I am an old-fashioned Physical Layer guy, because I prefer hardware demodulators (logic chips and OP amps!) with real-time displays (analogue oscilloscopes!) of Eye-Height and Constellation ;-)


    Regards,

    Michael, oh2aue

    ---

    "If you have data, you have something, if you do not, you have nothing." (Bengt Hultqvist, SK 24.02.2019)

  • 580/5000

    At my request on twitter Amsat-DL replied that to receive P4A telemetry AO40rcv is OK. But once received the data must be processed. Amsat-DL will make the telemetry equations public and only then can a specific program for P4A be written.

    Pure text messages can be read but telemetry data must be processed with the specific equations. Besides, I do not know what kind of parameters will be transmitted.

    Tensions, currents, temperatures, power, rx parameters and then?

    We have to wait for Amsat-dl to make this information public.

    73, Lucio IØLYL

  • Has the telemetry changed recently? Initially using AO40rcv I could decode the page with the message from Bochum and then later from Qatar but now the programme is not locking up at all. Last night I also thought I could hear some intermodulation on the beacon from a strong SSB station.


    73 Chris

  • I am using, but decode offline only.

    The stepps are in this order:

    - in ubuntu start the wine AO40Rcv.exe

    - in a browser I start to record a sample wav file from a websdr,s nb beacon signal. About 1 Mb is enough, because the beacon text and data arrive in a loop. Used the Audio recording menu of the websdr.

    - in the running AO40Rcv menu choose the Input Source, on the Select Input Source panel clikk the Use Wav File input checkbox, and from the file menu choose the recorded wav file

    - in the Output Settings menu on the Data Output Display/Setup panel choose your callsigne, an in the Select Folder menu select a directory path and filename

    - Clikk one of the 2 options starting "Log to File... text.

    - Choose OK to close this menu

    - Choose Signal F1 menu at the left side, if you want to see something in the black window.

    - Start the processing with the Start F12 button.

    - After the processing finished, check the log file in the choosed path.

    Here is a decoded beacon text example. Its format has DOS type carriege returns, not nice in linux:

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

    A HI, THIS IS AMSAT OSCAR-40 2000-07-30 22:49:32 #4820 +--------------------------------------------------------------+| RECONSTRUCTED FROM DECODED FEC BLOCK |+--------------------------------------------------------------+K HI de Qatar-OSCAR 100 (DL50AMSAT) UPT: 6d 5h 41m CMD: 22 LEI_REQ: 0 LEI_ACT: 0TEMP: 57 C VOLTAGES: 1.0 1.8 1.0 1.0 1.8 1.5 1.3 0.0 0.4 Volts TFL: 0 TFE: 0 TFH: 0 HFF: 0 HTH: 0 HR: 0L HI de Qatar-OSCAR 100 (DL50AMSAT) Transponder is open for general use since 2019-02-14. Enjoy the Narrow Band (NB) and Wide Band (WB transponders. Follow the guidelines and keep transmiter power below beacon. For more information visit: http://amsat-dl.org/ QO-100 was brought to you by Es'hailSat, QARS and AMSAT-DL. Good Luck and Good DX via the first geostationary P4-A satelliteA HI, THIS IS AMSAT OSCAR-40 yyyy-mm-dd hh:mm:ss #nnnn +--------------------------------------------------------------+| RECONSTRUCTED FROM DECODED FEC BLOCK |+--------------------------------------------------------------+L HI de Qatar-OSCAR 100 (DL50AMSAT) Transponder is open for general use since 2019-02-14. Enjoy the Narrow Band (NB) and Wide Band (WB transponders. Follow the guidelines and keep transmiter power below beacon. K HI de Qatar-OSCAR 100 (DL50AMSAT) UPT: 6d 5h 53m CMD: 22 LEI_REQ: 0 LEI_ACT: 0TEMP: 57 C VOLTAGES: 1.0 1.8 1.0 1.0 1.8 1.5 1.3 0.0 0.4 Volts TFL: 0 TFE: 0 TFH: 0 HFF: 0 HTH: 0 HR: 0 A HI, THIS IS AMSAT OSCAR-40 2000-07-30 22:49:32 #4820 +--------------------------------------------------------------+| RECONSTRUCTED FROM DECODED FEC BLOCK

    t.janos

  • Hi All

    I was able to decode the first time the telemetry of the QO-100 in realtime with the following software:


    http://antoninoporcino.xoom.it/P3D/index.htm


    It's like in the old days (1984) with OSCAR-10 and a Commodore C64 :-)


    I was not able to decode the Telemetry with the software AO40Rcv :-(


    73 de HB9RYZ

    Wolfgang