I wonder what causes the waterfall on fldigi to show a tiny activity on left edge but nowhere else. Setup: LNR-Precision LD-11 data port to Signalink to Windows 10 laptop. Transmission gets out well enough, PTT through mic port works well. USB Codec on send and receive on fldigi, native mic/speaker on the laptop. Latest version of fldigi, deleted and reloaded with no change in results. Attempted changing the waterfall values after checking online for numerous waterfall discussions. One last thing, if I change to audible, rig to laptop, then waterfall works as expected. Cables and lines have all been traced and check out ok. Any thoughts or suggestions? Again, a tiny waveform shows on the left vertical side of the waterfall display.