Just switched on 20MHz and the only real difference is the SNR and an increased CPU usage. It doesn’t change anything of the other values.
So nothing changed compared to my former testing.
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Hello all! I ran into a problem running the install script on a Pi 4 to a fresh build of Piaware v8, the image available from FlightAware. This is the airspy-conf script at GitHub.
The problem occurred when script runs:
“adduser --system --comment “Unprivileged user for running airspy_adsb” airspy_adsb”
It errors on the use of “–comment”
I think it still showed up as an error after updating the Pi and running v.9 of Piaware.
Running the script locally and editing out the comment seems to have worked.
Seems like that command switch is not part of Buster.
N.B. I’ve haven’t paid much attention to my FA system, it just runs. I had changed WiFi around and found I had forgotten logon password, so it was time to rebuild.
Thanks for adding Airspy support!!
comment argument removed, should be fixed, please try again.
I’d highly recommend https://adsb.im, it allows easily sending data to other websites in addition to FA if you’re interested in that 
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Looks exciting, downloading it now…
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I have a question about the configuration switch -t in the airspy configuration.
What exactly does this switch?
# -t <timeout> Aircraft timeout in seconds for the whitelist (default: 60)
Is it the time the after the aircraft disappear after the tracking signal is lost?
I played with the value between 60 and up to 180, but i don’t really see a difference
(btw: The default is 90 not 60 once you ran a fresh install of the airspy driver)
Thanks 
It’s decoder internals.
Whatever you view planes in has its owns timeout for how long planes are shown.
This is just the timeout until the -w threshold needs to be reached again and not merely refreshed by some message types.
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Hi,
Due to errors during decoding, it is almost a given that some of aircrafts will appear only once.
The whitelist function requires that a signal source accumulate a certain number of points. Different data packets have different values.
Once a source is added to the whitelist, it can be included on the map and transmitted. This minimizes the number of aircraft detected incorrectly.
After a specified period of time has passed since the last detection, its appearance is not automatically accepted, but is preceded by re-whitelisting (validation).
A timeout longer than 60 seconds may be significant when the station’s circular reception is not ensured, and due to terrain interfering with reception, passing aircraft are visible in certain directions for a short time, then reappear after more than a minute.
By fine-tuning the timeout, these signal sources that appear in “gaps” can be tracked more continuously.
Perfect, thanks for explanation
Just received an AirSpy mini but before bricking anything, do I need to remove any existing rtl-sdr drivers? Stopping the readsb service might be a good idea before running @wiedehopf 's airway-conf script, right?
https://github.com/wiedehopf/airspy-conf
Says nowhere that you need to stop anything or do anything.
Thus just run it.
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Good to know, thanks for the quick reply.
Here are the first hours, switched (at 10:45h) from Nooelec SDR to AirSpy mini. Some improvement, I have expected a bit more performance increase. This is a station under the roof, I might be able to do the same switch at our local airport’s receiver. Please let me know how to interpret these graphs and what I might need to change:
If you have obstacles around you (e.g. buildings, forest with tall trees, mountains, even if further away) then also an Airspy can’t create miracles.
Please also show the graphs of the message rate. You might also give us the content of the airspy_adsb config file (located in /etc/default). Maybe some parameters can be tuned.
which filtered LNA?
which antenna?
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Hi,
The need for a Gain=21 setting suggests that the system does not contain an LNA, perhaps it is placed at the receiver end of a long cable, or perhaps the LNA is not powered.
Set the gain to auto. It’s very good at selecting an appropriate level, but the airspy benefits a lot from an LNA. If you don’t have one then adding one should make quite a difference.
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Well said. I’ve tried my Airspy without the Uputronics LNA and identified it is almost deaf. even the unpowered FA filter (the dark blue one) is increasing the performance of the Airspy without LNA. So a filter LNA is a “must have” for the Airspy devices
And autogain works perfectly on my install
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- no filter, no LNA at this point, correction to my prior statement: I used a FlightAware ADSB stick (with filter and LNA) with a ~35dB gain, not a nooelec
- antenna is a GNS Electronics TEN90
I can certainly consider adding a uputronics, I already use a 868MHz uputronics for FLARM reception.
Another unrelated question: is the airspy_adsb decoder mandatory or in other words what would dump1090 do when directly accessing the Airspy stick through the default rtl-sdr driver? This questions arises in the context of Stratux to which I am contributing and which needs the particular Stratux output from dump1090 (–net-stratux-port 30006) …
Then you have lot of room for improvement. I am using an Uputronics 1090 filtered LNA. Works perfectly with the Airspy.
The only thing you need to consider is a good power supply unit. I have the Uputronics connected via USB cable to the RPi (with the original power unit), but it would work as well if you power the Uputronics dedicated