Ted et al.,
Just to review, there is a much simpler way to generate FT8 spots from a Red Pitaya. You do NOT need to run FT8Startup, CWSL_SSBWave, Virtual Audio Cable (VAC) or any other programs on Windows, not even a single copy of WSJT-X.
The FT8 decoding logic and almost everything you need is already pre-installed on the Red Pitaya SD Card (in Pavel's Alpine Linux distributions), ready to be enabled. The only downside is that you do have to dedicate a Red Pitaya to FT8 decoding, since it can only run one one app at a time, either sdr_receiver_hpsdr (for CW/RTTY Skimmer) or sdr_transceiver_ft8. but not both at the same time.
But buying a second Red Pitaya, or using an older one, is so much easier than setting up a Windows machine to do multi-band FT8 decoding, plus you don't have to worry about WSJT-X filling up your Windows hard disk with .WAV files.
The Red Pitaya FT8 app. automatically reports what it decodes to PSKReporter.info, and can "optionally" send the same reports to the RBN via the Aggregator, with no other Windows software required.
SM7IUN has excellent documentation explaining the procedure in detail, including handy setup scripts that automatically rotate between any 8 bands for day, night, and dawn/dusk.
I would strongly suggest trying this alternative before investing any effort into doing the same job on Windows, or buying another PC. Just follow all the steps, or if you get stuck, ask for help here.
73,
Bob, N6TV