NF FRA51602, Instruction Manual

Page: 180 / 286

5.6 Marker operations
5
-
24
FRA 51602
■ Automatic marker search when a sweep is completed
It is possible to register the marker search settings in advance so that the marker search can be performed
automatically when a sweep measurement is completed. Select the search item with
【
Marker
】
–
[AUTO
SEARCH] . If set to [OFF] , the search is not automatically performed.
The search method is the same as for manual search, but it is not possible to set the NEXT and PREV
operations.
Practical examples of automatic search are presented below.
(Example 1) : Automatic search for the low-pass filter cutoff frequency
Automatic search for the low-pass filter cutoff frequency is set to assuming a DC gain of 0 dB.
•
Set
[SEARCH VALUE Y1]
to −3.0.
•
Set
[AUTO SEARCH]
to
[Y1]
.
When a sweep is completed, the marker is automatically moved to the frequency for −3 dB. This is
convenient for adjusting the filter cutoff frequency. If the DC gain is other than 0 dB, sets those search
value for (DC gain −3 dB).
If the search item is set to PEAK, the search is performed for the peak frequency of a bandpass filter
(BPF); if set to BOTTOM, the search is performed for the bottom frequency of a notch filter (and
elimination filter).
Example of search for
the
−3 dB frequency.
0 dB
−3 dB