FlightAware Discussions

Does the SDR power consumption vary by # aircraft or is it constant?

I was assuming constant but I thought I noticed the 978 SDR being cooler than the 1090.

Using a lower sample rate: Around 2 MHz instead of 2.4 MHz.

The maximum data clock for both is the same 2 MHz.
But dump1090-fa does oversampling, dump978-fa does not.

Also i believe the encoding is different.

Is the 2MHz max for all SDRs or just the FA versions? I’m using NooElec Smart SDRs.

Also, how do you change the sample rate? Is that in a config file that has to be edited or is it changed through a command prompt like the SDR’s serial#?

The sample rate is selected in the programming of dump1090-fa and dump978-fa.

Old dump1090 versions used 2 MHz as well, quite a few less messages received.

The R820T2 RTL2832U based RTL-SDRs can sample up to 3.2 Msps, but above 2.4 Msps samples are dropped.

Yeah, the modulation is entirely different.

dump978 uses 2.083333MHz because that’s exactly twice the underlying bitrate of UAT which makes the demodulator simpler.