Using SDR For QO-100 Satellite Operation

Es’hailsat, otherwise known as QO-100 is the first geostationary satellite with an amateur radio payload on-board. The satellite contains both a Wide Band transponder for experimental modes and DVB-S Digital Television and a Narrow Band transponder used mostly for SSB voice and some digital mode contacts with other amateur operators. If you’re unfamiliar with this satellite we’ve covered it in previous articles, like in [Es’hail Transponder Now Active]

While many choose to use a transverter connected to a traditional amateur transceiver, others have turned to use Software Defined Radios to complete their satellite ground stations.

[Radio Innovation] posted a video back in March showing his contact on QO-100 using a LimeSDR Mini as the 2.4 GHz transmitter and a 10 GHz LNB for the downlink.

The PlutoSDR has been frequently seen used for QO-100 satellite operation on the Wide Band transponder due to its ease of DVB-S transmission utilizing software such as [DATV Express] but more recently there have been more and more operators turning to SDR for their day to day satellite operation.

It will be interesting to see how these stations evolve, perhaps by the time North America has access to a similar satellite, we’ll be prepared to operate it.

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What a shame it didn’t have a 70cm transponder so all could join in.


Are there any active plans for such a payload to cover North America?


small World Syed… I was just looking at your project pages just before I commented on this – Looking forward to that working in Europe –
Anyway, I hope you get an Amateur geo over there, but I do know that QO-100 took a LOT of work over a few years from AMSAT-de and the Qatar people to become a reality. Lobby AMSAT in the US 🙂


Definitely a small world. Some of the work we did for the EU beam has resulted in a very high stability LNB that can be used for QO-100. It is a sub-1000 Hz accuracy/offset LNB that can go down to 10.4 GHz. I’ll have more details in about a week.

RF Guy

is this a homemade modification (change PLL quartz to a TCXO) or is it a commercial high Stability LNB Project ?


It’s a purpose-built, commercially produced unit. I was reviewing production at the factory today. It’s guaranteed to have 1kHz of stability. Some of the samples were just a few hundred Hertz off.

RF Guy

do you have more information about this high stability LNB ? where/when to order ?


I wrote a step by step of how I got my PlutoSDR running full duplex in a “minimalist” way for es’hail-2
you can see it here on QRZ “Adventures with QO-100 and a PlutoSDR”