Operating on QO-100

Heard of QO-100? Also known as Es’hail 2, the first geostationary satellite carrying amateur radio transponders launched from Kennedy Space Center at 20:46 GMT on Thursday, November 15, 2018 and is now in a geostationary orbit at 25.9° East. These are the first amateur radio transponders to be put into geostationary orbit and the satellite footprint covers an area from Brazil to Thailand. The transponders are very wideband indeed, and have been designed to be relatively straightforward to access. Being a wide linear transponder, there’s plenty of room, but also plenty of activity, and the activity is in all sorts of modes, including digital ATV, digital voice, CW and SSB. The downlink is 10GHz and the uplink is 2.4GHz. These frequencies are no coincidence…

Receiving QO-100 is a matter of connecting an inexpensive commercial LNB, like you’d find on the arm of any Sky dish, to a suitable power supply via a bias-T, to an inexpensive SDR connected to your PC, including the RTL USB dongles, or indeed to any wideband multi-mode receiver that covers 7-800MHz. An unused Sky installation could be used pretty much as-is, by simply tweaking the dish to point to a very slightly different point in the sky – 25.9°. Indeed there are reports of QO-100 being heard via Sky dishes while the dish is still aligned on the Sky constellation at 28.2°E. PLL-equipped LNBs are better, but not essential.

Once you have a receiving setup sorted, it’s time to turn your attention to the transmitting side. The uplink is in the 13cm amateur allocation, adjacent to 2.4GHz Wi-Fi. There is a lot of room for creativity here, and lots of options. OE5HSR has pulled together an excellent PDF, which is pretty much a must-read for this topic. You can find this here.

I’m sure that some of our members will be having a go at working this unique satellite, and if you’re one of them, we’d absolutely love to hear from you at one of our show-and-tell evenings, or even better a live demo!

72000km+ SSB QSOs using a couple of watts and some recycled gear? Yes please!

Credit: AMSAT-UK for orbital and footprint information