RTL-SDR vs. Airspy on ADS-B Reception
With the recent release of ADSBSpy, an ADS-B decoder for the Airspy software defined radio, many people have been wondering how much better the Airspy is compared to the low cost RTL-SDR dongle at ADS-B reception. Over on his blog, Anthony Stirk has performed a test comparing an E4000 RTL-SDR with the Airspy.
In his test Anthony uses an A3 ADS-B antenna from Jetvision.de, and a HABAMP which is an LNA plus 1090 MHZ SAW filter. To create a fair test he used an antenna splitter and measured the reception of both dongles at the same time. He ran one instance of ADSB# for the E4000 RTL-SDR, and one instance of ADSBSpy for the Airspy over 24 hours and recorded the results.
![Airspy vs E4000 RTL-SDR](https://www.rtl-sdr.com/wp-content/uploads/2015/05/airspyvrtl_sdr.gif)
The results showed that the Airspy had approximately 50 km more range compared to the E4000 in some areas. More interestingly the stats showed that the Airspy received approximately 7 million more ADS-B messages compared to the RTL-SDR.
While there is no doubt the Airspy will perform better, one thing to note about this test is that it used an E4000 RTL-SDR which is widely considered to have inferior performance at the 1090 MHz ADS-B frequency when compared to the R820T/2 dongles.
![Airspy vs. E4000 RTL-SDR](https://www.rtl-sdr.com/wp-content/uploads/2015/05/airspyvrtl_img-500x281.jpg)
Comments noted and tests rerun with R820T2 dongle:
http://ava.upuaut.net/?p=808
Might not be a completely fair test. The E4000 has a tuning gap approx 1100-1250 and ADS-B is 1090. Many of the E4000 tuners don’t pick up ADS-B at all and I suspect many others don’t get very good reception so close to the gap. This test needs to be redone with the R820T and R820T2 dongles.
I agree as most of us use the R280T dongles. As for comparison the Airspy has been produced for SDR and ADSB but the RTL2932/R280T dongles were made for DVB-T, DAB, analogue tv reception. Whoever found out that we could use the dongles for SDR and ADSB is a genius!