JDS Uniphase OneExpert DSL, User Manual

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Chapter 8 Copper Testing
Measuring longitudinal balance
OneExpert DSL User’s Guide
April 2014 22052280, Revision 001
67
Measuring longitudinal balance
Balance is a number representing the quality of the telephone circuit and the degree to which the
Tip (A) and Ring (B) conductors are electrically the same in their ability to cancel noise. The balance
measurement is used to identify poor loop quality or cable bonding and grounding issues that allow
excessive loop noise. Wideband background noise is covered in the WBTIMS section.
To measure longitudinal balance
1 Connect the Tip (A), Ring (B), and Ground (Earth) leads to the line under test.
2 From the Copper menu, touch the Long. Balance button.
The Longitudinal Balance menu appears.
The test begins automatically.
3 To save the results to a report, use the Tray menu ( “Saving a report” on page 32 ).
4 To learn what your results mean, see “Longitudinal balance” in Chapter 10 “Test Results” .
Measuring balance is complete.
Detecting load coils
The OneExpert DSL can detect up to five load coils that may exist on the line, out to 27,000 (8,200
meters) feet. It will also report a short, open, or a high noise condition, if detected. For accurate load
coil detection, test on a pair without voltage (supplied by a battery). Although the detector will work
with voltage on a pair, accuracy will be compromised. In addition, the detector works best when the
last coil is followed by 1200 feet (336 meters) of cable.
To detect load coils
1 Connect the Tip (A), Ring (B), and Ground (Earth) leads to the line under test.
2 From the Copper menu, touch Load Coil .
The Load Coil Detector menu appears.
The count appears in the box. If at least one load coil is detected, the distance to the first load
appears.
If noise, a short, or an open is detected, it appears on this screen.
3 To save the results to a report, use the Tray menu ( “Saving a report” on page 32 ).
4 To learn what your results mean, see “Load coil” in Chapter 10 “Test Results” .
Detecting load coils is complete.
NOTE:
The distance to first load measurement assumes no other impairments are present between the
OneExpert DSL and the first load coil. If other impairments are present, accuracy is reduced.
If voltage greater than 50V peak is present, the test will abort.