1.  Introduction

2.  Spécifications

3.  Détails de construction

Figure 1. 

Figure 2. 

4.  Testing

  • BE01 mounted on 120 cm dish, powered by bias tee

  • IF output connected to a PlutoSDR via low-pass filter and attenuator

  • PlutoSDR TCXO disabled by grounding pin 1

  • 25 MHz output connected to 30 dB amplifier and injected into XTALN of AD9363 via 470 pF decoupling cap

  • PlutoSDR firmware configured to expect a 25 MHz clock (see [MADEL20190105])

  • PlutoSDR tuned to 739.675 MHz, sampling at 300 kHz

  • CW beacon tracked by GNU Radio "PLL Freq Det" block

  • BPSK beacon coarsely derotated by CW beacon tracker, then demodulated by GNU Radio "Clock Recovery MM" and "Costas Loop" blocks.

Figure 3. 




5.  Conclusion et perspectives


[LNBLINEUP] Comparaison de têtes de réception satellite . http://www.pabr.org/radio/lnblineup/lnblineup.fr.html .

[ESTEVEZ20190323] Measuring QO-100 beacons frequency . 2019. Daniel Estévez. https://destevez.net/2019/03/measuring-qo-100-beacons-frequency/.

[AT20190406] A Measurement of Frequency Accuracy and Doppler of the QO-100 Satellite Transponder Beacon . 2019. Andy Talbot. https://g4jnt.com/QO100_Stab.pdf.

[MADEL20190105] PlutoSDR clock input . 2019. Tobias Mädel. https://tbspace.de/plutosdrclockinput.html.