Looking for the user manuel for the FLEX 6400

And, if you haven't found them, here is the SmartSDR v3 User Guide:

SmartSDR Software User Guide v3.x – FlexRadio

And the SmartSDR CAT User Guide:

SmartSDR CAT User Guide v3.x – FlexRadio

Note that you can key in a search term on the line at the top left of the document list. That makes it very easy. I found all these references in a matter of seconds.

73, Craig KØCF