Anritsu FAQs
Sometimes the SPA displays "ATTEN", "RBW" or "VBW" with a "*" after them. What does that mean?
Attenuation, RBW and VBW can all be automatically coupled or manually coupled. When automatically coupled, the attenuation changes as the reference level is changed, the RBW changes as the span is changed and the VBW changes as the RBW is changed. When they are manually coupled they can be changed independently. The "*" after the parameter indicates that it is manually coupled.