HP ESA-L1500A, User'S And Calibration Manual

Page: 98 / 326

Chapter 4 97
Front-Panel Key Reference
Search
Search
The
Search
key accesses the following marker and search function
menu keys.
Max Pk
→
CF
places a marker on the highest peak, and then changes the spectrum
analyzer settings so that the peak is placed at the center frequency.
Key Access:
Search
Mkr
→
CF
changes the spectrum analyzer settings so that the frequency of the
marker becomes the center frequency. Key Access:
Search
Mkr
→
Ref Lvl
changes the spectrum analyzer settings so that the amplitude of the
active marker becomes the reference level. Key Access:
Search
Next Peak
places the marker on the next highest peak. The signal peak must
exceed the peak threshold value. If there is no peak, the marker will not
move. (Also see the
Peak Excursn
and
Pk Threshold
key descriptions.)
Key Access:
Search
Next Pk Right
moves the marker to the next peak to the right of the current marker.
The signal peak must exceed the peak threshold value. If there is no
peak to the right, the marker will not move. (Also see the
Peak Excursn
and
Pk Threshold
key descriptions.) Key Access:
Search
Next Pk Left
moves the marker to the next peak to the left of the current marker.
The signal peak must exceed the peak threshold value. If there is no
peak to the left, the marker will not move. (Also see the
Peak Excursn
and
Pk Threshold
key descriptions.) Key Access:
Search
Peak Excursn
sets the minimum amplitude variation of signals that the marker can
identify as a peak. If a value of 10 dB is selected, the marker moves only
to peaks that rise and fall more than 10 dB above the peak threshold
value. Pressing
Preset
or turning on power resets the excursion to 6 dB,
and the threshold to 90 dB below the reference level.
NOTE
Two signal peaks, which are so close together that the amplitude drop
between them is less than the peak-excursion value, are not recognized
as two peaks. A signal peak is recognized only if it has a peak excursion
drop above the noise floor, on both sides of the signal.
When the peak excursion value is 6 dB or higher, the marker-peaking
functions may not recognize signals less than 6 dB above the noise floor.
To correct this, when measuring signals near the noise floor, the
excursion value can be reduced even further. To prevent the marker