M. Why is there a wide noise strip, e.g. after pushing "Pre"?
After pushing "Pre", the 9100 operates in full span mode with the "Normal" detector setting. Th 9100 carries out measurements with a higher frequency resolution than it can display on the frequency axis. Several measurements are combined into one frequency value. For all the frequencies within a resolution step, the highest and the lowest level are calculated. The 9100 displays a vertical line between these points at the respective frequency.
If you switch the detector to the "Pos. Peak" setting you will only see the largest value for each frequency. "Neg. Peak" results in the smallest value and "Sample" in the last value to be displayed for each frequency step.
The "Normal" setting usually allows for the fastest signal detection since the smallest and largest values are shown concurrently.
