Measuring Distance to Fault with the ZPH

This video demonstrates how to make basic distance-to-fault measurements using the Rohde & Schwarz ZPH cable and antenna analyzer.
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Timeline:
00:00 Introduction
00:13 Suggested viewing
00:28 About distance to fault (DTF) measurements
01:29 Steps in making the distance to fault measurements
01:53 Starting distance to fault measurements
02:15 Configuring the tracking generator
02:48 Measurement setup - direct vs. DUT cable
03:43 About cable models
04:31 Creating a custom cable model
05:30 Configuring cable length
06:30 Configuring center frequency and span
07:20 Configuring additional parameters
07:51 About one port calibration
08:48 Connection calibration standards for DTF measurements
09:19 DTF measurement result
09:41 Measurement results - DTF list and threshold
10:26 Using markers
10:57 Summary

[@bladimirgenoves1080]

What is the Freq that is used when measuring distance to fault?

[@pauldenisowski]

The frequency range (since modern DTF measurements are usually FDR - frequency domain reflectometry) is user selectable. Clearly you would want a frequency range that covers the frequencies that would be used in your system, but there's also a tradeoff between frequency range and distance : greater frequency ranges show more detail, but decrease max distance. I discuss all of this in the upcoming presentation "Understanding VNAs - Distance to Fault Measurements", so please stay tuned!

[@bladimirgenoves1080]

Is this measuremt similar to TDR?

[@pauldenisowski]

Similar, but not the same. TDR (time domain reflectometry) basically sends a pulse and then determines how long it takes for that pulse to be reflected back from the other end of the cable (which is ideally open or short). Most modern analyzers use FDR (frequency domain reflectometry), where the analyzer sweeps a frequency range and then uses an inverse fast Fourier transform to convert the frequency domain reflections into the time domain (and therefore into distances). FDR has many, many advantages over TDR for this application, and my upcoming presentation "Understanding VNAs - Distance to Fault Measurements" discuses these differences.