LANTEK User Manual - Ideal Industries

Chapter 3
Structured Cable Field Calibration and Testing
Power Sum NEXT and Power Sum ELFEXT
Power Sum tests measure the crosstalk effects of three transmitting pairs on the
fourth pair in the same cable sheath.
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2
3
6
4
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Effects of
3 Pairs on 1 Pair
During the Power Sum NEXT test, six measurements are made at each end of the
cable and combined (pairs 1-2, 3-6, and 4-5 vs. pair 7-8, etc.) for a total of eight
measurements.
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1
6
3
5
4
8
7
Figure 3-14: Power Sum NEXT Test Screen
During the Power Sum ELFEXT test, twelve measurements are made at the DH side of
the cable and combined (pairs 1-2, 3-6, 4-5 vs. pair 7-8, etc.) for a total of four
measurements.
Figure 3-15: Power Sum ELFEXT Test Screen
Note: Power Sum NEXT measurements will generally read 2 - 3 dB lower in value
(higher crosstalk) than conventional NEXT.
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