I am unsure why there is such a strong supplemental signal with the FengYun satellites always beginning with a cut at ~-150kHz from the expected frequency propergating to ~-100kHz on the waterfall.
Those wider observations shows the DC spike from the SDR, the default tune offset is 100kHz so with the narrower 48kHz waterfalls it is not visible.
When using higher sample rates and doing wider observations you can increase the SATNOGS_LO_OFFSET to move it further away.
I’m running at 8MHz wide and based on least amount of spurs chose a offset of 2MHz, ofc this needs to be well within the sample rate and leaving room for the actual frequency of interest (:
Look at the metadata of obs 7872972. samp-rate-rx: "8e6", lo-offset: "2e6"
On station 1918 it’s running at 5MHz, so 1MHz offset should be safe ?
That is a good point. Thanks! We missed the LO Offset while configuring and changed it to 1MHz.
The newest FengYun observation looks better than before and misses the DC spike.
Reducing the sample rate of the Pluto solved the audio waterfall issue. This in turn possibly causes Satnogs to crash if high bandwidth satellites like Umka-1 or Birkeland are observed.