[solved - delete pls] Signal bleed between channels

[Bob Sava]

I have what appears to be a signal bleed.  CH1 (yellow) wave is a calibration signal, CH2 (purple) is a 10kHz square wave from external AWG.  When I unplug or stop AWG yellow vertical line stops.  Display is set for 5s persistence to show the motion of the vertical line.  Later screenshot shows purple signal (CH2) coinciding with the movement of the yellow vertical line.  If I plug AWG signal to any other channel, that are on separate ADC, ghost signal does not show.


EDIT: I'm unable to delete this topic.  After doing more tests I think crosstalk occurs outside of the oscilloscope, because part of the signal path on CH1 is unshielded (probe and/or calibration signal leads)