Displays on 6400m 6600m

The display on my 6600M never goes to sleep - it's on when the radio is on. That said, you do not need to have it displaying a panadapter and slice when you are not using it from the "M" front panel - it ends up being mostly dark, displaying a connection screen when another (PC or Maestro) GUI is connected to the radio (I use v2 SSDR, so that's my only choice).

Just make sure the front panel is not "configured" (i.e. did it last time) to put up the GUI and the panadapter won't come up. I suppose that could be forced by loading a different radio software version using your PC SSDR, and not having that version on the "M" front end.