SAT Controller SDR Nano

  • Thats ok. Only the LNB LO frequency will be corrected. The tuned RX frequency will not be changed.

    Thank you for explanation.

    All the time i was thinking that there is a closed loop between master beacon and the lower beacon to compensate the drift.

    So i have to adjust a signal all the time manualy.

    This was not so clear for me.


  • You don't have to adjust a signal all the time manually.

    The LNB LO frequency of GQRX will be corrected automatically by the drift correction function of "SAT Controller SDR Nano" software. And thats all we need. Then the system is stable and there is no more (significant) drift in the demodulated audio.

    The displayed RX frequency will not change. But the "real" RX frequency (IF of SDR stick) changes automatically depending on changing LNB LO frequency.

    Only during warm up time of the SDR sticks there will be a little drift. But after that time (5-10min) your RX signal will be stable.

  • Hello Frank,

    Again i will try to explain my problem with SAT-Controller V0.2.

    SAT-Controller is locked to Master beacon.

    CW beacon signal is on the marked position "CW" in GQRX.

    SAT-Controller corrects the"LNB LO" according the drift of the LNB.

    So far everything is fine.

    But now when LNB drifts also the signal from "CW beacon" drifts also from marked position "CW".

    This means the "LNB LO" is corrected but the tuned frequency for the signal "CW beacon (10.489.548.500 Hz)" does not follow or is not corrected.

    What can be the problem and how to fix it?

    73, DH2VH

  • Some questions:

    1. Do you use a non wobbling PLL LNB (like Octagon)?

    2. Do your SDR sticks both have 0.5ppm TCXO or better?

    3. Do you have run GQRX and SatControl 10-15min for warming up?

    4. Is "Drift correction" button switched on?

    5. Do you see a low drifting value in field "RX ERR"?

    Then all should be ok. The displayed RX frequency will be fixed on 10.489.548.500 but there should be no significant drift in demodulated audio. So the signal in audio waterfall (GQRX/View/Audio) should be stable on 1.5k.

    If not, maybe there is a problem with unstable/drifting SDR sticks. In my system i use two NooElec NeSDR Nano3. They works fine.

  • 1. Unmodified LNB GM-201

    2. Yes NEWGEN.RTL2832SDR, TCXO 0,5ppm

    3. Yes warm up for 1 hour and more

    4. Yes "Drift correction" switched on

    5. Yes i see drifting in "RX ERR"

    But there is a significant drift in demodulated audio in value of drift.

    This is my problem.

  • Thats very mystic. If LNB LO is corrected the demodulated audio should be follow. At the moment i have no idea why not.

    If i correct my LNB LO frequency by 100Hz the demodulated audio changes excactly 100Hz too. For a simple test you can do this manually (GQRX/View/Input controls) with only GQRX is running.

    Important: After changing LNB LO frequency you have to retune to 10.489.548.500 Hz.