In order for the RSPdx to work with HDSDR an extio_xx.dll is required. It is my understanding that SDRplay will not be developing one for this device.. They have published specs on how to develop extio dll’s and are leaving it to users or 3rd party developers to write one. I hope they change their minds because HDSDR is a very useful program that is favoured by many MW Dxers and SWLs.