Software Defined Radio (SDR) on Ubuntu Linux

I live near the airport and always wanted to listen to the air traffic, so recently I decided to go forward with it and bought a cheap DVB-T USB dongle.

It turns out that those cheap dongles can tune more than lousy TV channels as found out by Eric Fry when trying to make his dongle work under Linux, the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation. Kudos also to Antti Palosaari and Osmocom for much of the work getting the RTL2382U and it’s associated tuners tamed allowing a low cost path into SDR for newbies like me.

Please be aware that some dongles have different hardware:

The RTL2832U outputs 8-bit I/Q-samples, and the highest theoretically possible sample-rate is 3.2 MS/s, however, the highest sample-rate without lost samples that has been tested so far is 2.56 MS/s. The frequency range is highly dependent of the used tuner, dongles that use the Elonics E4000 offer the widest possible range.

The cheap dongle from Banggood uses the RTL2832U in conjunction with the Rafael Micro R820T tuner which allows you to have a frequency range from 24 MHz to 1766 MHz, one of the best combinations possible.

Before connecting the dongle we have to blacklist the DVB-T drivers so we can use rtl-sdr to unlock the features.

$ sudo nano /etc/modprobe.d/blacklist.conf
$ sudo apt-get install rtl-sdr

Ubuntu 14.04 LTS already has on it’s own repository the tool Gqrx but it’s quite outdated, let’s live on the bleeding edge shall ya ?

$ sudo add-apt-repository ppa:gqrx/snapshots
$ sudo apt-get update
$ sudo apt-get install gqrx

And that’s it !

As I play more with the dongle expect additional articles about the subject.

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