SaxAlyzer
From ON0DAS
Saxalyzer is a piece of software for Windows, written in C#.net. It can turn a CAT-compatible tranceiver into a spectrum analyzer. This can be used in conjunction with a white-noise generator and an attenuator to measure and tune filters
Ofcourse the refresh speed of the display is not a quick as a commercial spectrum analyzer, but it is not aiming to be a commercial analyzerb
Currently no version is available for download as there are still some bugs to be fixed and features to be implemented.