Agilent Technologies FieldFox N9913A - DTF (Distance to Fault) Measurements

30 FieldFox User’s Guide
DTF (Distance to Fault) Measurements
CAT Mode Distance to Fault (DTF) measurements are generally used to locate
problems, or faults, in a length of cable or transmission line. In this chapter, the
cable to be tested is referred to as the DUT (Device Under Test).
Settings that are NOT unique to DTF measurements are documented in the CAT
Mode chapter on page 20.
In this Chapter
How to make DTF Measurements ....................... 30
DTF Settings Table ................................................ 31
DTF Measurement (Format) ................................ 31
DTF Start and Stop Distance ............................... 31
Frequency Mode ..................................................... 32
Coupled Frequency ............................................... 33
Cable (Correction) Specifications ....................... 33
Window Settings .................................................... 36
DTF Units ................................................................ 36
Calculated DTF Values .......................................... 36
About Alias Faults ................................................. 37
Optional settings
Markers .................................................................. 148
Limit Lines ............................................................ 158
Save Measurement Settings and Results ......... 164
Trace Math is NOT available in DTF Measurements.
How to make DTF Measurements
Before starting, you may need the following:
 Jumper cable or adapter to connect the beginning of the DUT to the FieldFox.
 LOAD with correct connector type and gender to terminate the end of the DUT
(if possible).
 The known length and cable type of the DUT. If the cable type is not known,
then the Cable Loss (dB/Meter) and Velocity Factor of the DUT are required.
1. Connect any necessary jumper cable or adapter to the FieldFox RF OUT port.
Do NOT connect the DUT.
2. Press Preset then Preset to return the FieldFox to the default settings.
3. Then Mode then CAT.
4. Then DTF.
5. Press Freq/Dist, then Stop Distance and enter the length of the DUT. You
can optionally set the Start Distance.
6. Press Cal 5 and follow the Cal prompts. Learn all about Calibration on
page 53.