Agilent Technologies FieldFox N9912A, User Manual

Page: 25 / 209

CAT (Cable and Antenna Test) Mode 25
How to set Scale

Press
Scale / Amptd
.

Then choose from the following:
1.
Autoscale
Automatically adjusts the Y-axis to comfortably fit the Min and
Max amplitude of the trace on the screen.
2.
Autoscale All
Autoscales all of the traces on the screen, useful only for
dual-trace configurations.
3. Set Scale, Reference Level, and Reference Position:
o
Scale
Manually enter a scale per division to view specific areas of the trace.
o
Ref Level
Manually set the value of the reference line. Enter a negative
value by pressing
Run/Hold (+/-)
either before or after typing a value.
o
Ref Position
Manually set the position of the reference line. Values must be
between 0 (TOP line) and 10 (BOTTOM line)
4. Set Top and Bottom graticule values. The scale per division is calculated.
o
Top
to set the value of the Top graticule.
o
Bottom
to set the value of the Bottom graticule.
o
Enter a negative value by pressing
Run/Hold (+/-)
either before or after
typing a value.
Scale annotation on the FieldFox screen
· Reference Line = red arrow
·Ref Level = -40 dB
· Ref Position = 1
· Scale = 2 dB per division
Averaging
Trace Averaging helps to smooth a trace to reduce the effects of random noise on
a measurement. The FieldFox computes each data point based on the average of
the same data point over several consecutive sweeps.
Average Count determines the number of sweeps to average. The higher the
average count, the greater the amount of noise reduction.
An average counter is shown in the left edge of the screen as
Avg N
. This shows
the number of previous sweeps that have been averaged together to form the
current trace. When the counter reaches the specified count, then a ‘running
average’ of the last
N
sweeps is displayed. Average Count = 1 means there is NO
averaging.
This setting can be changed at any time without affecting calibration accuracy.
How to set Trace Averaging

Press
BW 2
.

Then
Average N
where N is the current count setting.