Agilent Technologies ESA-E Series User Manual page 19

Used to define the stop position of the range over which faults will be measured.
Stop Distance
The smaller the value of this field, the more closely faults can be viewed.
Therefore, the value should be set as close as possible to the length of the test
apparatus.
The default value is 20 m.
The number of trace points used in the measurement. Changing the number of
Trace Points
trace points affects the minimum and maximum measurable distances. As a
general rule, the longer the cable, the more trace points you should use. It is
possible to select up to 8192 trace points but due to the computationally-intensive
FFT, the higher the value, the slower the measurement becomes. To ensure the
fastest possible speed, use a value that is a power of 2—for example 512, 1024 and
so on.
Window Used to select the FFT windowing function to be used. The cable fault
measurement uses an FFT to convert the analyzer frequency trace into a distance
trace. To get the best possible results from the FFT, it is important to apply the most
suitable windowing function to the frequency trace before performing the FFT.
Possible values are Rectangular, Flat Top, Gaussian, and Hanning. The default
value is Flat Top. The following table describes these values.
Function Description
Rectangular Results in no windowing.
Flat Top The five term flat-top
(default) window. A good window to
use when making amplitude
measurements of relatively
pure tones.
Gaussian A five term cosine window
that resembles a Gaussian
window.
Hanning Has a good frequency
resolution and reasonably
good side-lobe roll-off, but
poor main-lobe flatness and
relatively large side-lobe
peaks.
Restores all
Restore Meas
Defaults factory defaults.
Advanced Provides access to the following advanced measurement parameter settings:
Res BW
Chapter 2
Max Side-Lobe
Level
–13.3 dB
–95.1 dB
–125 dB
–31.5 dB
parameter values for the current measurement to their
Meas Setup
Used to set the resolution bandwidth used for the measurement
and to define whether it is automatic or manual. Default values
are 3 MHz and Auto.
Menu Maps and Key Descriptions
Cable Fault Location
Side-Lobe Max Main
Roll Off
20 dB/decade
60 dB/decade
–3.92 dB
+/–0.00208 dB
–0.68 dB
–1.42 dB
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