While the total cost of the project was a little under $200, that’s still better than the $350 to $2000 for a commercial SDI signal generator. If you want to play along, the files are out on GitHub.

An Arduino is used to control the SI5351 clock generator, which in turn is controlled by the same program created for the SDR Shield. With the audio signal fed to HDSDR, [Aniss] was able to pick ...