FlightAware Discussions

Strange loss of positions/aircrafts and range

Hi all,

I’m quite new to ADS-B tracking. I started last month and it all went really well. FA Pro Stick Plus, Raspi 4, spiderantenna and a nice range of more than 150 nm from within the building. From one minute to the other I lost the range down to 15 to 20 nm and the amount of aircrafts per day went down from >1200 to 200. This change happened when noone was at home. So no change of equipment, no change of antenna position, no SW change, nothing.
I thought of a broken stick sent it back. Yesterday I got a replacement and the range is still around 15nm. And also the amount of aircrafts is back at around ~200 per day.

Can anyone guide me around to figure out what happened?

I’m quite familiar with linux as os, so working in the shell is not a problem, but I don’t know where to start.
The SW I use is an install of openhabian (based on raspian), FR24 feeder, piaware and adbsexchange feeder.



Antenna outdoor? Could be the weather then, maybe cable, connector, corrosion, water

Do you have by chance anotherSD card and reinstall it for testing?

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I had a cat that did something to an antenna. Never sure just what, but I had to do the disconnect/reconnect and wiggle things a bit to get a receiver working correctly again. Perhaps replug all connections and connectors from antenna to the receiver dongle. Worth the quick try. Good luck

Thanks for sharing your ideas!

I stripped the whole installation down to the pure initial openhabian OS yesterday. And then started to install all feeders step by step. The problem appeared again after installing the readsb package.
I stepped this step back and re-configured the flightradars dump1090-mutability to handle also the feeds to FA and adbsexchange.


This package is unmaintained. Please use something more modern.

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That’s a decoder.
You can’t have the issue without a decoder.

And the actual demodulation between the alternatives is pretty similar, so they should result in roughly the same message rate / range.
So the most likely cause for your issue would be configuring a gain that’s too high or too low.

Thanks for the hint. Currently I’m so glad, that is ‘only’ a software issue and not a second damaged device :wink:

As I pointed out, I just started with the whole topic. I’m not deeply in that topic but does the readsb library changes the values for gain on it’s own?

I will spent some more time to replace the unmaintained dump1090 fork as soon as possible.

Maybe this can help you:
If you would rather use readsb, you can use this:

It’s not a library and no it doesn’t change gain on its own.
The default might be a different gain, not sure.

Thoughts on optimizing gain

I’ll try the first suggestion as the second led to the issue. Thanks

I doubt that.
Where are you checking aircraft count anyhow, which stats are you looking at?

See my stats here https://flightaware.com/adsb/stats/user/X0815

Somewhen in the afternoon of August 21st the stats dropped down and stayed the level until August 27th when I sent back the device as I thought it was broken.
Initially I had the same values when plugging in the new device two days ago. Yesterday I started rolling back the installation and installed the packages step by step until the range dropped again.

But for today the values are looking good, or?

Did you also compare the sites near to you? This is also an indicator of downs and ups. Normally not that high, but never knows…

Yes, in deed, todays values a pretty good. At least for the equipment in use (spider antenna indoor).

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