Ah OK Peter, I misunderstood you. Meanwhile I had another Idea. I will look for a new SSTV software and VirtualAudioCable. Then I can record the sound on my beloved OS/2-ArcaOS-5 and play it on Win10 into the SSTV program. I think this should work ? If not, I can try your suggestion.
Lucio, I logged in as administrator. In the settings the soundcard was only found in the output field. Without soundcard found in the input I can't play the sound from a WAV/MMV-file.
AMSAT-UK: https://amsat-uk.org/beginners/iss-sstv/