Make sure Soundcard/Devices (Configuration menu) is set to PortAudio and Capture/Playback set correctly. If you're using a radio like the IC-7300, with built-in 'soundcard' then select USB Audio CODEC for both. Radio must be connected (USB) and powered when launching FLDigi or it'll look for something else, like system microphone/speaker. Good luck! -- Charles
W9ARO