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Getting some hands on experience with the signal processing side of SDR, with GNU Radio can help with understanding things like negative frequencies, complex signals, etc.

It's open source, and you can just play with your audio ports for starters. Later adding a $40 rtlSDR kit goes a long way. I used mine to build a VOR receiver.

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As a pilot with an amateur radio license (though an inexperienced ham) this sounds really interesting. Could you elaborate more on building the VOR receiver?

The transmitter has an electronically switched antenna that virtually moves in a circle at 3600 rpm, causing FM modulation phased with direction. The carrier is also AM modulated with a reference phase signal.

I built a gnu radio flowgraph to receive both and display heading to the VOR.

Woah coming from a dsp / synth background that’s wild to hear.

Sorry I was working from memory yesterday... It's 1800 rpm / 30 Hz, not 60.

https://en.wikipedia.org/wiki/VHF_omnidirectional_range

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