Posts by ES5PC

    Hello,

    Yesterday I did my first uplink attempts on Es'hail-2. On Rx side I use an old 2.6 m prime focus sat-tv dish with PLL-locked LNB (NJR2637E) and USRP N210. Transponder noise floor is up to 20 dB above background noise. Both Rx and Tx LOs are phase locked to a common 10 MHz rubidium clock. On TX I tried first my 4.5 m dish with a CP septum feed designed for 13 cm EME work and about 10 W otput from PA into 15 m (not so low loss) cable. This gave by far too much EIRP for the satellite. As a quick fix I used a 6 dB attenuator at PA output, but it was still a bit too high. Later I just tried with 10 W power into septum feed without dish and got still audible CW signal. I will most likely make a more permanent setup with a small dish in near future.

    73, Viljo ES5PC


    Hello,


    For me the most stable and reliable SDR software so far has been HDSDR. It also supports a large selection of SDR hardware via its extio dll interface. As I use USRP N210 in some applications I had to modify the extio to support external 10 MHz reference. Also for LEO satellite tracking I added TLE based doppler compensation in the extio interface. For EME work I use spectravue with SDR-IQ. At home I also run Ubuntu linux as VM under vmware player. Just built gqrx from source with a small modification to enable external reference for USRP. Under linux gqrx runs stable, no crashes observed so far. Using it also for Es'hail-2 beacon reception. I have tested bandwidths up to 5 MHz with FFT sizes up to 262144 without major problems. The only problem I see is related with intermittent audio buffering problem in the version compiled from source while the version distributed as binary package don't seem to have such problem. It could be related to the latest QT5 version used to bulid the software.


    73,

    Viljo ES5PC

    Yes, it looks like correct signals. Congratulations! There seems to be only some frequency offset in your downconverter chain. With the LO locked to a rubidium clock reference beacons are currently only less than 500 Hz away from their expected frequencies.

    73,

    Viljo ES5PC