Soapy gain settings

We (@cgbsat and I) have some issues with the Dwingeloo telesope’s gain settings. We have two feeds (horizontal and vertical polarization).

Example observations are SatNOGS Network - Observation 4792471 (bad, taken with B210 on H-feed) and SatNOGS Network - Observation 4792479 (good, taken by @cgbsat) with other dongle on V-feed).

We have pretty excluded that the difference is based on the polarization. We’ve explored some different gain settings, but I notice that the gnuradio Soapy block actually sets a lot of gains, where only ‘overall gain’ is set by the SatNogs parameter gain. Could it be that one of the other gain settings (which seem to be hardcoded) is non-optimal?

pinging @surligas and @Sleepwalker that might have an idea on it.

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Hi! From the metadata in both of these observations i can see that “gain_mode” is set to Overall. In this case, soapy uses the driver algorithm that sets the various gain stages based on the one, overall value that has been set. Thus, the individual gain values like PGA, LNA etc are not set by gr-soapy. This will happen only if “specific” or “settings_field” is given as “gain_mode”, which is not the case as i understand.

Ok, thanks. Then we will continue to tweak only the one gain setting. I was afraid the parameter space would be much larger!