Good point. I will check these settings in Data Mode on the K3s. Data mode should be USB already but your suggestion #1 and #2 may be the issue. I bought the radio used and the previous owner could have set something up goofy.
Suggestion #3: Already reset the frequency in the preferences in WSJT-x and I do see FT8 sigs in the waterfall.
B Smith, this is RX not TX. Why would the power slider matter?
