The RSPduo is popular for diversity tuning.  This works both with Windows SDRuno and the newer multiplatform SDRconnect.  However, anyone can make use of the documented API to do their own thing and this is what John, VE6EY has been doing as reported in a  series of updates on his “Making it up” blog.

In his January blog, John includes a video describing where he’d got to with his project to create his own SDR receiver, capable of diversity tuning and how he was extending it to provide a recording and playback function.

His main use case is to enable listeners to time shift their diversity experiments using dual channel recordings. Especially for MW DX. Users can record a chunk of the band and playback to identify different stations on the same frequency using beamforming.

All this and much more can be found on the “Making it up” blog website