Observation 4547841: NOAA 19 (33591) - Again disappointing due to interference

Regarding Observation 4547841
Quite good waterfall apart from interference and ‘blue’ gaps again. All of which is manifested in the Audio.
Any thoughts on the sound source(s) of the interference, please?

The blue ‘gaps’ around 130 seconds into the observation look to me like your receiver system is getting overloaded from some nearby transmitter.

The other noise throughout the observation (and there is a lot of noise there) is difficult to pin down, but it’s the usual kind of thing many stations experience when they are being locally noise limited. It could be anything from LED lights, to some other bad power supply near your antenna, to other overload related issues. Pretty much all modern electronics are noisy on the 2m band now-days, so the first thing to do is get as much physical separation between your antenna/LNA and any other electronics as possible.

I have isolated my SATnogs station from other equipment, and there are no other electrical items powered up during the Observations. My location is very rural and there are no known transmitters locally. Perhaps increasing the gain will help.
So more experimentation needed.
Many thanks for your comments.

In a situation where your system is overloading, increasing the gain is going to do the opposite of help. It will make things even worse. Also, looking at how you are using an Airspy and your observation metadata, I think you have your gains set incorrectly.
You are using the ‘Overall’ gain mode setting, and a single number in the gain field. SoapySDR is incredibly dumb in how it distributes that gain value amongst the different gain settings available (for the Airspy you have LNA, MIX and VGA), resulting in poor performance.
You need to be using a gain mode of “Settings Field” such that the numbers that you have already entered into your ‘other settings’ field are actually used.

I would suggest looking at the output from the SDR using some other software like CubicSDR or GQRX to get a better idea of what’s going on and set the gain values appropriately. You need to keep watching for a while to see if/when these overload issues occur.

There is a guide on how to access your stations receiver remotely via CubicSDR here: Omnidirectional Station How To - SatNOGS Wiki
Just note that with an airspy you should have more than one gain slider.

@vk5qi many thanks for your advices. My Airspy setup has now been modified, particularly the gains, along the lines you suggest and better results are being obtained.