Hi Mike -
Set sweep range:
Start 46 MHz
Stop 54 MHz
Then set Marker | Center.
You'd expect the marker to be a 50 MHz, but instead it's at 46 MHz. If
you attempt to move the marker, the sweep range changes.
Based on my experiments,
firmware uses (only) last selected marker to set START, STOP, CENTER, or CW.
SPAN seemingly uses 2 markers...
Oristo