FAQs from Rohde & Schwarz

UNCAL message after manual changes in the Coupling menu


I made some manual changes in the COUPLING menu and got a UNCAL message on

my display. What is the reason for this, and how can I cancel the UNCAL message?


In the COUPLING menu you can make manual changes for resolution bandwidth (RBW),

video bandwidth (VBW) and sweep time. The settings for resolution bandwidth,

video bandwidth, frequency span and sweep time affect each

other. If the combination of these settings in the manual setting is

inappropriate, the UNCAL message is displayed at the bottom of the screen, to the right of the

scale. If the UNCAL message is displayed, the measurement level accuracy cannot

be ensured.

Please change the following settings to cancel the UNCAL message:

- Expand the resolution bandwidth (RBW)

- Expand the video bandwidth (VBW)

- Slow the sweep time

- If RBW or VBW cannot be changed, narrow the frequency span