The perfect Gain


I’m trying to optimize my ground station and that why (at least for now) I’m playing with the gain!
From just the visual perspective my optimal gain with the old waterfall coloring was at around 14.4 - but with the latest waterfall coloring it seems that my optimal gain is somewhere between 20.7 to 28.0

Is this correct? How I can find the best gain for my station… with the professional way and not just looking how “cool” a waterfall looks?

I let others talk about it, as they probably have more experience than me. A quick way is, as you said, looking on the waterfall and another one looking on decoded data. For example a NOAA pass with very good quality image, or even better several FSK demoded data on UNISAT-6 or BUGSAT-1.

I want also to mention that in case you use rtl-sdr, there are specific values for gains, you can find them either in the wiki or by running rtl_test command in your raspberry pi.


I’m still trying to find the perfect gain!

First of all yes, I’m using the RTL-SDR v3 module and the gains I use are from the wiki page (16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6).

But, is it possible to use variable gain depending on the satellite under observation? For example (at least for my station) it seems that the perfect gain for the NOAA satellites is around 20.7 (more than that and it saturates the waterfall with noise), for most of the satellites is around 29.7 and for few of those is around 38.6

So, can I set the gain when I’m setting an observation from the web or at least from the Satnogs-Setup section on the RaspberryPi to use a table that says for NOAA sattelites to use the X gain, for FOX satellites to use the Y gain and for any other satellite to use a Z gain?

Unfortunately variable gain is not possible with the current client. I’ve just submitted an issue about on client in order to discuss how it should be implemented.