According to a few comments around the internet, the new RTL2832u – R820T2 version was said to be a bit more sensitive and had less of a noise floor than the older R820T version. So being curious about this, we dropped $24.95 on one to see what all the fuss was about. After doing a few quick unscientific real world tests pitting the new R820T2 against the older R820T, it appeared the rumours might be true after all. However while the results weren’t night and day, there definitely were some noticeable improvements in sensitivity and lower noise over the older R820T. In the ADSB tests, the new R820T2 blew the older R820T away in the distance and number of ADSB packets received. So for ADSB, the R820T2 is the better dongle and would definitely worth replacing your older R820T if you are running an ADSB setup. One interesting note is that allegedly the new Airspy SDR radio will be using the R820T2 chipset. The Airspy is to be priced at $199. Needless to say, it would be pretty interesting to compare the $24.95 R820T dongle to the Airspy to see what $175 more gets you.
The quick comparison was performed by connecting the two dongles to the same computer and using two instances SDR Sharp to run the dongles simultaneously. The two instances of SDR Sharp were configured exactly the same and were using the standard Zadig drivers. Both dongles were plugged into identical 3.5 inch whips. The newer R820T2 antenna was not used so as not to skew the results. So, this was truly a head to head realtime comparison. Each dongle was set to the same frequency in a few different frequency ranges for the tests. The only slight issue was that there were a few milliseconds of lag time between the two instances of SDR Sharp, but not enough to make any real difference. Two separate instances of RTL1090 were used for the ADSB reception tests. The core I3 PC handled both dongles just fine.
Judging by the results below, it appears that the R820T2 would be a worthy upgrade for R820T users and it’s only $25!
Here are some screenshots of the results:
The R820T and R820T2 pluged into their antennas and a USB hub ready to go!
FM Band Reception
Both dongles seemed to perform similarly. Really seemed to be not much of a difference in the FM Band.
National Weather Service Band
Here we can see the R820T2 begin to pull ahead in sensitivity and not quite as noisy as the R820T.
Here we see the R820T2 is just slightly more sensitive on 800 MHz, but has a significantly lower noise floor.
Again the R820T seems a bit quieter with a little stronger ADSB pulses. The pulses are represented as small blips in the waterfall. Notice that the pulses are slightly brighter in the R820T2 waterfall than the R820T waterfall indicating a slightly stronger signal.
ADSB Data Collection with RTL1090 Software
Ok, the RTL820T2 just kills the R820T on ADSB by picking up double the number of aircraft in roughly a 3 minute period. Both programs were started at the same time and stopped at the same time.