Frequency Stability of the QO-100 NB Transponder

  • Thanks Peter!


    I agree there is nothing wrong with QO-100 :) - our investigation mostly focused on the frequency accuracy of the transponder LO to determine the source of the frequency offset that was observed, not so much on its frequency stability. Nevertheless, the measurements did show some interesting features related to stability as a nice side-effect :)


    I have also updated my blog post to correct the (likely) incorrect hypothesis that the wiggles are caused by stationkeeping maneuvres, this is based on the excellent work by EA4GPZ and others.


    Thanks Peter and your team for the great work in making a Geostationary satellite available to the amateur community!


    73,


    Wouter Jan PE4WJ

  • ...

    Disclaimer: I cannot and will not give any technical details of the QO100 transponder due to NDA. But I think it is obvious that any space-qualified transponder oscillator will have very good stability values so for the sake of simplicity we assume it is non-significant compared to the numbers above.

    ...

    73s Achim, DH2VA


    Ok, it seems fair to me. However some features of the "Melco" Satellite Platform DS2000, the same as Es'Hail-2, are known.

    Here the characteristics of the Beacon (commercial). The same that we find on V. 10.706 GHz.

    Maybe we can start from here?


    P.S.
    not everyone is able to receive this Beacon as it transmits on MENA Beam



  • Thanks Peter!


    I agree there is nothing wrong with QO-100 :) - our investigation mostly focused on the frequency accuracy of the transponder LO to determine the source of the frequency offset that was observed, not so much on its frequency stability.

    Hi Wouter Jan,


    Thanks! Yes - absolutely correct regarding frequency accuracy and stability.. indeed both are covered and referenced above, while originally analyzing the short term frequency stability, an offset of ~70 Hz in frequency accuracy has been indeed observed.. I should have better emphasized this...


    73s Peter