ADS-B Antenna comparison
This is a comparison of three ADS-B antennas: a OPA-5 from Embedded Development GmbH, the GNS HULC-M from GNS Electronics and my simple DIY built.
This is a pure hobbyist test and comparison of ADS-B hardware that you can buy online.
I have no relation with Embedded Development GmbH nor GNS Electronics GmbH.
Equipment under test #
(in that order)
- Modes-Beast with OPA-5 antenna, see Shop Jetvision
- GNS HULC-M antenna, see Shop GNS Electronics
- Modes-Beast with DIY antenna
Test location #
The Ipf mountain.
Elevation 668m above MSL
Test setup #
Test time #
Start: 10.05.2020 14:00
End: 10.05.2020 17:00
Each antenna setup was operated for 1 hour.
- Modes-Beast with OPA-5 antenna: 14:00 to 15:00
- GNS HULC antenna: 15:00 to 16:00
- Modes-Beast with DIY antenna: 16:00 - 17:00
Time shown in graphs is not correct due to Raspberry Pi clock being out of sync while running offline.
Additional test hardware #
- Raspberry Pi 3B
- DietPi image based on Raspian buster
- readsb v4.0.0 ADS-B decoder software
- USB Power pack
- Monitoring PC connected via Pi's Wifi hotspot.
readsb run command line options #
./readsb --device-type modesbeast --beast-serial /dev/ttyUSB0 --max-range 0 --no-modeac-auto --net --lat 48.87131 --lon 10.35730 --no-modeac-auto --rx-location-accuracy 1 --write-output-every 5 --write-output /run/readsb --stats-range --quiet ./readsb --device-type gnshulc --beast-serial /dev/ttyUSB0 --max-range 0 --no-modeac-auto --net --lat 48.87131 --lon 10.35730 --no-modeac-auto --rx-location-accuracy 1 --write-output-every 5 --write-output /run/readsb --stats-range --quiet
readsb performance graphs #
readsb polar range graph #
Note: These graphs depend on maximum distance of aircraft seen in any 5° sector during runtime.
Some thoughts at the end #
(in loose order, expressing my personal opinion)
- Compared to the GNS HULC and my DIY antenna the OPA-5 has a higher gain and therefore a higher effective aperture, hence better performance.
- The GNS HULC-M seems to have a smaller dynamic range than Modes-Beast. Looks like an AGC is involved.
- The included GPS in GNS HULC is a nice option. Makes it suitable for mobile ADS-B receivers. (readsb v4.0.0 supports frequent position update)
- Would be interesting to see a GNS5894T receiver module combined with an OPA-5 antenna. I expect a significant raise in performance (over the HULC).
- There is not much difference when comparing the GNS HULC with Modes-Beast + DIY antenna. I'm positive surprised about that DIY antenna performance.
- As usual in RF, a good antenna is the most important and first step toward good performance.
- If you are willing to invest a fair amount of money then the Modes-Beast + OPA-5 combo gives you the biggest bang for the buck.
Special thanks to Gian Dido for temporary provision of the GNS HULC-M antenna.