I am unable to get my K3 to TX any RF when set up for FT-8. Hardware is K3, Behringer U-phoria UMC202HD USB sound card running on WIN XP with most recent version of WSJT-X software. FT-8 settings Radio Tab: baud 38,400, data 8, stop 1, handshake none, PTT CAT, Mode data/packet, split none. Tests of CAT and PTT are both successful. Soundcard tab is set for the Behringer card.
Soundcard is cabled to LIne In, Line Out on K3. I am in Data A (USB) mode. K3 Menu Mic Sel is set to line in/line out. Waterfall displays signals and they decode properly.
When I click the tune button in the FT-8 software, the K3 goes into transmit but there is no RF out. When I press the tune button on the K3 I do get RF out. When we briefly attached a headphones plug to the soundcard out lead that had been connected to the K3 line in we could hear the tuning tone when clicking on the tune button in FT-8. I do AFSK RTTY without difficulty so I do not think the line in jack is faulty.