I recently re-engaged my passion for satellite work. Why? Because it is challenging and because it represents a frontier in amateur radio that I had not seriously explored before. First, I will address the challenge. Because satellites can only be accessed when they are in view, you need to know when they are overhead. This issue is handled by downloading the Keplerian elements that define the satellite’s orbit and using pass-prediction software. Once that problem is solved, you need to address getting into the satellite with your signal. The best antennas for this purpose are Yagis, and they need to be aimed in the azimuth and elevation planes. I recently built the system Fred Kemmerer AB1OC discussed in his blog. You can read about it here: https://www.n1fd.org/2017/02/22/portable-satellite-antenna/ I aim my antennas using a Yaesu G5500 rotor and a homemade computer controller. I am willing to share my plans and software with anyone who wants them. Finally, because the satellite is traveling very rapidly, you need to account for the Doppler effect by adjusting the tuning of your transmitter and receiver during the satellite pass. This adjustment can be done with computer control through your radio’s CAT port. Note that all of this needs to be done while engaging in the QSO! It is precisely that challenge which inspired me to take up satellite communication. My initial goal was to get VUCC satellite – by working 100 grids using any combination of amateur satellites. I just achieved that goal this week – thanks to a little miracle satellite called Greencube.
Greencube is a Medium Earth Orbit satellite that was launched by the European Space Agency in 2022. It carries multiple payloads for scientific experimentation. One payload is a telemeterized pressure chamber carrying a garden of microgreens to help us understand how vegetation can grow in space. Someone is going to have a really exotic salad if that chamber is ever recovered (just joking – that probably won’t happen)! The other payload is an amateur radio digipeater to test performance of amateur radio equipment in a region of space exposed to high levels of cosmic radiation. Use the satellite while we have it! What is tremendously exciting about Greencube is the fact that it is high above Earth – 5500 km to be exact. That means it has a wide footprint – about 1/3 of the planet. It also is overhead for ca. 1 hour at a time. This combination makes for excellent DXing – and working rare grids.
There is a downside to Greencube – actually a couple. First, the satellite is running shared missions. Therefore it is not always available for amateur use. You can find out more by following #s5lab on twitter or going to https://www.amsat.org/status/ to check the status of the bird. Second, the satellite’s signal is very weak. That means you need both a 70 cm Yagi antenna and a preamp (preferably mast mounted) to hear it. Fortunately, it is a single band satellite, so your equipment setup can be more modest than a high-end system for working the Low Earth Orbit satellites. KH6WI in Hawaii is using a small tripod with a ca. 13 element horizontally polarized beam to work Greencube. His station remains an unconquered frontier for me, but I am determined to get him – I have heard him on the satellite, so that is a first step. Finally, the satellite operates packet only on SSB (Upper Sideband). You need to download special software to decode it and work it. You can find out more about Fred’s setup here: https://stationproject.blog/ (July 30, 2023 entry).
How did I get started with Greencube? Fred Kemmerer AB1OC told me about it during a NE Division Cabinet Meeting three weeks ago. I immediately downloaded the materials and got started. Since then I have conquered VUCC Satellite (certificate arrived today) and am on my way to Satellite DXCC (a new dream for me). I have 30 countries confirmed so far. I know this will be a tough goal. Despite the satellite having a broad footprint, there are not that many people equipped to use it – especially in developing countries. The good news is that there are plenty of rovers going on expeditions to activate rare grids and entities.
What does the typical Greencube QSO look like? It’s pretty much like FT8. You send your callsign and grid square number, the other station sends theirs, you then send RRR and your name and QTH- or just 73 and thank you, and the other station acknowledges in kind. It’s short and sweet, but because the satellite can only pass one signal at a time, there can be challenges just getting that much information through.
I am hooked on this satellite – it is my new favorite. I also enjoy RS-44 (a Russian satellite with a good footprint) and FO-29 (a Japanese satellite with similar parameters). SSB Voice communication is the norm there, and you can have a short ragchew if you wish. It’s a different thrill compared to working DX on HF. While there is magic in working the world with a wire antenna, there is an equal if not greater thrill when doing it through an object the size of a suitcase moving at 17,000 MPH (Low Earth orbit – Wikipedia)! Not even the best skeet shooter could hit that bird.
The lesson in all of this is that much like science (my day job), there is always something to learn in this hobby – a new frontier to explore. I am having a blast with this one. Yes, it requires some investment of time and money, but the rush is like no other. I encourage you to give it a try. All you need to work satellite is a dual-band HT or mobile rig and an Arrow handheld Yagi – or you can homebrew your own antenna. The FM birds are great – check out this page for helpful information Work FM Voice Ham Satellites This Week! (work-sat.com). I got started in satellites this way, and my obsession grew from there. Or – find some other aspect of the hobby that interests you and that you have not yet explored. There is probably someone in SECARS willing to help you out, and your adventure in radio will only get stronger. Good luck, and I hope to hear you on the birds someday!
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