User's Manual Part 2

March 29, 2006 Part ######A revision 00a-DRAFT 99
Chapter 5: Antenna Installation Procedures
Measure the Distance to a Fault
Distance-to-fault (DTF) is a measurement of VSWR or return loss based on distance. A DTF test
indicates the distance to a short, open, or load. Perform a DTF test whenever a VSWR test reveals that
the antenna system is not operating within specifications.
To accurately interpret the results from a DTF cable sweep, you need to know the lengths of your
cables and the location of any devices or connectors attached to those cables. Comparing the results of
the test with the layout of your antenna system will help you to determine if problems are caused by
faulty devices, connectors, or cables.
 To measure the distance to fault
1 Power on and calibrate your cable sweep analyzer.
2 Power off the RFSS module connected to the RF equipment you want to test. See page 108 for a list of
circuit breakers.
3 Carefully disconnect the RF equipment and cables you want to test.
4 Connect the cable sweep analyzer to the equipment and cables you want to test.
NOTE: Be careful not to damage any cables or connectors when connecting the
analyzer to the RF equipment.
5 Perform the cable sweeps.
See the documentation that comes with your analyzer for information about performing the cable sweep
and interpreting the results.
6 Document the results from the cable sweeps according to the MOPs of your site. Keeping records of
periodic cable sweeps will make troubleshooting future problems easier.
7 Carefully disconnect the analyzer from the RF equipment.
8 Reconnect the RF equipment and cables back to the RFSS module.
If any of the connectors are outdoors, ensure that they are resealed according to the procedures of your
site.
9 Power on the RFSS module. See page 108 for a list of circuit breakers.