Generating White Noise with an FL2K Dongle
The FL2K project allows us to turn a cheap USB 3.0 dongle into a fully transmit capable SDR (filters still required for high power work). We have posted about the FL2k project several times on this blog since early 2018.
Recently we thank reader Mikael for submitting a fork of the Osmo-FL2K driver code which he writes enables it to generate white noise with uniform amplitude distribution. This could be useful for projects that require a wideband noise source such as when attempting to measure filter and VSWR of antennas.
IK1XPV, author of the code notes that the current code is only tested on the Windows driver branch, via compilation on Visual Studio 2019 at the moment. The main contributed code can be found in \src\fl2k_noise.c.
this link to Oscar’s blog is also quite important:
https://sdr-prototypes.blogspot.com/2021/01/fl2knoise-generator.html
Very cool use of a 64-bit Linear-feedback shift register to generate pseudo random numbers. Perfect for testing frequency responses.