World’s Most Complicated FM Radio [RTL-SDR]

After many hours of trial and error, I’ve turned my computer into one of the most complicated FM radios imaginable – and it’s nearly free. With just a cheap ($11) TV tuner based on the Realtek RTL2383 chipset and some free software for Windows/Linux/Mac, you can have your own Software Defined Radio receiver that can decode nearly every type of transmission imaginable from 50MHz-1800MHz, with the right antennas.

I’m using it to listen to my local FM radio station, KNDD 107.7 The End.


In this graph, you can clearly see the HD Radio sidebands (HD1 and HD2) as well as the main carrier. It’s present in both the waterfall, and the waveform. The sidebands are digitally encoded on either side of the analog carrier on the center frequency. This station is centered on 98.9 MHz (KLCK-FM/ HD1/ HD2 “The Click”) and plays a a mix of Top 40 and Alternative/Rock.

I’ll be posting more about RTLSDR in the future, including a guide on getting set up with RTL-SDR. In the meantime, back to experimenting!