QO-100 or Es-hail 2 satellite has been the epicenter of ham radio world the last few months. Everybody is rushing to receive and transmit to the satellite, using the most cost efficient way, according to ham radio spirit!
After a small research, I decided to use my old 1.2m offset sat dish for Rx. The first experience was quite disappointing, although it was very easy to find the satellite, the old LNB was drifting sooo much that it was nearly impossible to hear SSB audio from the narrow-band transponder.
Here is a screenshot from GQRX using RTL-SDR.com usb stick:
After a small research, I decided to use my old 1.2m offset sat dish for Rx. The first experience was quite disappointing, although it was very easy to find the satellite, the old LNB was drifting sooo much that it was nearly impossible to hear SSB audio from the narrow-band transponder.
Here is a screenshot from GQRX using RTL-SDR.com usb stick:
So I had to get a new LNB. The cheapest PLL LNB was Octagon Green OSLO for just 3,9 Euro from the local market! I ordered two, just in case one gets broken.
After installing the PLL LNB the difference was tremendous! I could now hear SSB audio on Narrow-band transponder!!!
Next challenge of course was to receive DATV from the wide-band one. I had no DATV hardware, neither I wanted to use any, because SDR!
At first I thought it was so easy like using SDRAngel DATV plugin, only to find out that it's not yet DVB-S2 compatible, but it's already a requested feature.
After a small research I found twitter posts by F4DAV stating success! So I had to get my hands on Leandvb software. I downloaded, compiled it and guess what? No DVB-S2 either!
More reading and many many failed tests leads to further instructions on enabling DVB-S2, using a different branch of code.
After enabling DVB-S2 I got some better plots and numbers, but still no video! It seems like software DVB-S2 decoders for amateur use are still at an experimental phase of development, and require much better SNR in order to properly decode the video stream. LDPC_tool did the job quite well and only with about 6-7 dB MER I had real-time 2Mbaud video from QO-100 satellite using the B200 SDR!
I don't want to spend your time by posting all the failed attempts, I will just post the 2 magic lines that led to success!
mkfifo speqtrum.iq
uhd_rx_cfile -A RX2 -f 742.250e6 -g 60 -r 4e6 spectrum.iq
./leandvb -f 4e6 --sr 2000e3 --cr 2/3 --standard DVB-S2 --f32 -d --ldpc-helper ./ldpc_tool < spectrum.iq |vlc -
