HP 8712ES User Manual page 148

Figure 4-7
To Use Multi-Peak
or Multi-Notch
Search
NOTE
Using Instrument Functions
Using Markers
−6 dB Notch Marker Search
Multi-peak and multi-notch searches are designed for use when
measuring multi-pole filters. Both automatically search the
measurement trace from left to right, and position a marker at each local
maximum or minimum. Up to eight maximums or minimums will be
found. Searches are limited to responses above −60 dB. With marker
tracking on, the multi-peak/notch search will be performed after each
sweep.
During a multi-peak or multi-notch search, eight markers are always
placed on the trace, regardless of how many peaks or notches are found.
The markers that aren't placed on a peak or notch are placed at the far
right of the display on the current maximum frequency point.
A maximum (or minimum) point is detected whenever an amplitude
excursion greater than half of a division occurs. The half of a division
excursion requirement must be satisfied on both sides (left and right) of
the peak (or minimum). The maximum (or minimum) point must be
> −60 dB. See
Figure
4-14
4-8.
ES User's Guide