Dtf Units; Bandpass Mode - Agilent Technologies FieldFox N9912A User Manual

DTF Units

By default, X-axis units for DTF measurement settings are displayed in Meters.
How to change DTF units
 With a DTF measurement present, press Freq/Dist .
 Then
 Then
 The current selection is underlined
Frequency Mode
All DTF measurements are made with frequency settings and, using Inverse Fast
Fourier Transform (IFFT), the time and distance to faults are calculated.
How to set Frequency Mode
With a DTF measurement present,
 Press Meas Setup 4
 Then
 Choose one of the following:
Typically, you will set the frequency range of the measurement to the passband
of the filter. However, you may also want to test the ability of the filter to reject
unwanted frequencies. In this case, set the frequency range to include those
frequencies which the filter may not be adequately rejecting.
When the DTF frequencies are set manually, they may not be the optimum
frequencies for measuring the distance to fault. The distance may no longer be
alias-free. Learn more about alias-free range on page 35.
How to manually set Frequencies in Bandpass Mode
 Press Freq/Dist
 Then
 Then
OR
 Press
 Then
30
More
DTF Units.
Frequency Mode
The frequency range of a DTF measurement is set
Lowpass Mode
o
automatically based on the Start and Stop Distances. Use Lowpass mode
when the DUT is a cable ONLY.
(Default setting) The frequency range of a DTF

Bandpass Mode

o
measurement is set manually. Use Bandpass mode when the DUT contains a
diplexer or other filtering device which does not pass some frequencies.
and type the start frequency to use for the DTF
Min Start Freq
measurement.
and type the stop frequency to use for the DTF
Max Stop Freq
measurement.
More
Max Freq Span and type the frequency range to use for the DTF
measurement.
m (meters) Feet.
N9912A FieldFox User's Guide