1. AMSAT SA Space Symposium 2019
Amateur Radio’s First Geostationary Satellite, QO Presenter: Hannes Coetzee, ZS6BZP
AMSAT SA Space Symposium 2019

2. Overview QO-100 background Dynamics of geostationary orbits
QO-100 narrowband linear transponder
Possible ground station solutions
Practical demonstration

3. Es’hail-2 Background
The Qatar Satellite Company (Es’hailSat)’s 2nd satellite, Es’hail-2, was launched by a SpaceX Falcon 9 rocket on 15 November 2018
Launch was delayed for 3 years
Commissioning and maneuvering took more than 2 months
Became operational during February 2019
Qatar Amateur Radio Society (QARS) managed to secure the privilege to have an Amateur Radio payload on Es’hail-2
Became Qatar-Oscar 100

4. Satellites in Geostationary Orbit
Circular orbit above the equator
Orbital period is equal to the Earth’s rotational period
Satellite thus appears motionless to ground observers
Can only happen at an altitude of km above mean sea level

5. High Altitude Amateur Satellites
All previous high altitude amateur satellites were in highly elliptical orbits to increase area coverage and on-station time
Orbits didn’t always favour South Africa
Were known as Phase 3 satellites
Phase 3A was lost at launch, P3B (AO-10), P3C (AO-13), P3D (AO-40)
AO-40 operated from 2000 – 2004
Geostationary satellites are referred to as Phase 4 with Qatar-Oscar 100 being P4A

6. Gain and Beamwidth from a Geostationary Orbit

7. View from 25.5°East

8. QO-100’s Footprint

9. QO-100’s Footprint Covers a population of 5.2 billion
Nearly 1.5 million Radio Amateurs
225 DXCC entities
Footprint extends from eastern tip of Brazil in the west to Vietnam in the east
Does not include mainland USA

10. QO-100 Narrow Band Linear Transponder
Built by AMSAT DL
Uplink to MHz (250 kHz bandwidth)
Right hand circular polarization required from Earth stations
Downlink to MHz
Vertical polarization
Preferred modes are SSB and CW
5 Watt uplink power into a 60 to 75 cm offset dish is adequate
LEILA 2 (LEIstungs Limit Anzeiga) input power limiter
Ensures fair play and that the satellite is not hogged by a few, very high power transmissions
In short, running higher power than what’s necessary is counter productive

11. Possible 2.4 GHz Uplink Solution
2m, all-mode radios very common (e.g. Icom IC-706)
10W output on 2m also very common
Will form the basis for the transverter driver
Transverter can be based on W1GHZ’s modern approach

12. 2.4 GHz Transverter Blockdiagram

13. Packaged Chinese 5W, 2.4 GHz WiFi Amplifier ($50) (Gain = 17 dB)

14. PA0RWE PIC Controlled, ADF4351 PLL VFO (35 MHz – 4.4 GHz)

15. F6KBF Arduino Controlled, ADF4351 PLL VFO (35 MHz – 4.4 GHz)

16. ADF5351 PLL Evaluation Board ($20 from China)

17. 10 MHz to 6 GHz HackRF One SDR TX (needs an amp to get to 100mW)

18. Possible 10.489 GHz Downlink Solution
High stability Ku-Band DSTV LNB is a good candidate
Select GHz LO by means of 12V supply
IF is at 739 MHz for GHz input
Far from any amateur band
No problem with RTL-dongle based SDR solution
Spectrum and waterfall display with the SDR solution
Click to tune operation

19. Possible QO-100 Receiver Chain

20. Universal Ku-Band LNB Block Diagram

21. Bias-T (DC Injector) Circuit Diagram

22. Avenger High Stability PLL LNB

23. Octagon Oslo High Stability PLL LNB

24. Locally available Elsat LNBU10.6 High Stability LNB

25. Low Cost RTL Dongle Receiver

26. 80cm Transmitter and Receiver Dishes

27. SDR# Spectrum and Waterfall Display

28. Web SDR (zr6aic.giga.co.za:8903)

29. The End
Demonstration
Have fun!