FlightAware Discussions

HOWTO: Airspy mini and Airspy R2: Piaware / dump1090-fa configuration

Pretty sure I saw a comment from @prog in some thread where he mentioned that it uses linearity mode.
Should be the same thread where the excel file with this table was posted originally…

Found it.
It uses linearity mode…

interesting, on the table for “linearity” mode some steps are shown as 3dB, some as 2dB and a few as 1dB…it doesn’t matter in the long run but i too had believed it was 3dB per step (and maybe it is…and the table is not correct for the mini???)

That’s just settings, not dB numbers.

You don’t know what dB the settings are related to.

Took my existing piaware dual 1090/978 config and swapped out the 1090 dongle for an AirSpy mini, ran your script and everything works.
Nice. We shall see how the stats change over time, but looks like it is decoding more messages.

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I have used this script on an Orange Pi One with Armbian Stretch and it worked great!

This is the older version with H3 CPU, and 1GHz max frequency. The CPU usage hovers around 70% with m=12 and temperature about 71C with a passive cooler only (hot day today, 96F/35.5C outside).

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Had a day off so enough time to replace my Rpi 3B+ & orange FA dongle with an Rpi 4 & Airspy mini. I’m pleased with the results especially because I’m still waiting for the RTL-SDR LNA to arrive from China.
Amplification is at 21 and I gave it a try at 20MHz oversampling.

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Very nice improvement

I find my airspys deaf without a pre-amp. You should see a large improvement with one(You may need to optimise the gain but they have a larger dynamic range so it may work with 21). I had to put a cavity filter between the antenna and amp as there is so much noise in my area.

The rtl-sdr LNA has some prefiltering (high pass to remove audio/tv analog broadcast) and also doesn’t overload as easily because the gain is divided in two stages and there is a SAW filter after the first stage.

@Jon: I’m using a cavity filter as well, I loose about half of my reception without it due to a cell tower nearby at 960MHz. The signal is so strong that my spectrum analyser picks it up even without the test leads attached to it!

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@wiedehopf: They have 2 versions, I ordered the one without filters because I already own a cavity filter.

Temperature and cpu load seems better than expected @20MHz.Pi4%20load%20and%20temp

Well your cavity filter won’t have the 60 dB out of band attenuation the combined filtering in the filtered preamp has, or does it?

Good luck with it, probably will work fine when it’s working good now without a preamp.
Also note that the wideband amp has less gain, though that’s not really a problem.

Nothing beats a cavity filter, attenuation @ GSM900 is already >80dB and drops to 100dB even further away, insertion loss is <= 1dB

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Has anyone with an airspy mini modified it to improve RF isolation? This video shows the details - bit long, but basically scrape off some anodising and add a nut and washer to connect the SMA barrel to the case. It seems to make a noticeable difference:

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My airspy mini already has a nut and washer installed

I think mine has too.
Still a very interesting video :slight_smile:

Ah they must have updated it to include it in manufacturing now. I wouldn’t be surprised since that guy is Leif Asbrink who wrote Linrad and is very knowledgeable about SDRs in general and is pretty well respected.

yes, early airspy mini did NOT have the nut and washer…current product does have