SDR : Software Defined Radio


Recently, I’ve been busy playing with Software Defined Radio (SDR).  I was able to get my hands on one of these cheap TV dongles with the Realtek 2832U Chipset.  So what’s the big deal?

A V4L/DVB kernel developer  Antti Palosaar, discovered that the chip allows transferring the raw I/Q samples to the host, which is officially used for DAB/DAB+/FM demodulation.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 2.8 MS/s. The frequency range is highly dependent of the used tuner, dongles that use the Elonics E4000 offer the widest possible range (64 – 1700 MHz with a gap from approx. 1100 – 1250 MHz). When used out-of-spec, a tuning range of approx. 50 MHz – 2.2 GHz is possible (with gap).

Linux / OSX Users can use gnuradio to play with SDR.

On Windows you have a nice piece of software called, but you need to apply a patch and relevant driver to get it to work with the RTL chip.

I’ve successfully been able to tune into Radio and TV signals. I have spotted what can be possibly Pager signals but have not decoded them, and I’ve spotted my car keys operating around the 433MHz range.

Stay tuned for updates…