We can still change the USB cable 
Yeah buying an USB cable with appropriate ferrite cores might help a little bit.
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I bought quality 6" USB3 (overkill) pigtails, with ferrites, for this. They also work for the STD RTL and FA dongles.
I just replaced the heatsink tape with heatsink adhesive on some RPI3B+ and 4B heatsinks. Too soon to see if they are a lot cooler. I also did the heatsinks I had on the Airspy mini. The tape couldn’t handle the heat in the attic.
I may add heatsinks to a few RTL-SDR dongles. The two I use for Bias-T seem to get very warm.
AirSpy Mini Upgrades:
Mine also came with the internal tooth lockwasher under the SMA nut.
I split the USB cable and cut the red wire so I could power the AirSpy with its own linear 5.0 volt supply. That is to reduce noise from the Raspberry Pi and its switching power source.
I’m using a remote LNA in front of the AirSpy. The LNA has its own ultra low noise LDO regulator using the TI TPS7A4701 device.
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The automated script didn’t completely work for me - it installed the airspy decoder and service, but didn’t update the configuration of dump1090-fa. That’s quite likely my fault however, because it’s been edited quite a few times in the past and is probably not exactly in the format the installtion script was expecting. Anyway, it was simple to correct and all is working now.
It should overwrite that configuration file and back up the version it encountered on the first run.
cp -n /etc/default/dump1090-fa /etc/default/dump1090-fa.airspyconf
wget -q -O /etc/default/dump1090-fa $repository/dump1090-fa.default
The second command should overwrite it.
Run it again?
Oh nevermind, working is working.
That’s very nice!
Is it the same station or do you now have a second one?
(Oh, already seeing the spike in the FA stats)
It’s exactly the same, just swapped the dongle over. I had already swapped the pi 3 out for a pi 4 because I wanted my media player back
Runs at 20Mhz sample rate with plenty of cpu to spare.
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I’d say go with a gain of 17 or 18 for a start.
It’s already on 18. I’ll leave it a few days and see how it goes:
The difference in quality of tracks is very noticeable. They are much more consistent.
The positions per second should have increased quite a bit.
Is it possible to use the airspy with dump978-fa, given it is taking SoapySDR config types for the receiver?
Yes, but i’m not sure if it’s worth it.
It’s not doing oversampling like the custom airspy_adsb.
Should be, though I don’t have an airspy to test with. Some of the soapysdr drivers can be picky about what they’ll support - please try it out and let me know if you run into problems.
airspy_adsb does UAT?
No it doesn’t, not what i meant to say
Just saying that the improvement you see with 1090 MHz using the airspy won’t be the same when upgrading your UAT reception from rtl-sdr to an airspy.
I have tested it and you corrected the heavy CPU usage i had an issue with.
Apart from that it seemed to work, obviously could only test that it’s running, nothing to receive in Europe.
I believe someone back then successfully tested it.
I finally got my amp for the Airspy and installed it this evening, just let the stats speak for themselves…
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Those track with single message numbers look ugly, do you have -x activated?
I wouldn’t recommend that option, it produces quite a bit of bogus aircraft sighted.
Also personally i’d turn down the airspy gain down at least 2 notches.
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Yeah, completely forgot to change this after having added the amplifier.
-x is now gone and I turned the gain back to 20, this is the one stage 18dB preamp unlike yours.
My airspy, with two stage amplifier, has the gain set at 19.
I did oscillate between 18, 19 and 20 and I think 19 was better in my location.
You have a lot of cable though.
Also the Airspy will perform equally well in quite a range of gain numbers.