LANTEK User Manual - Ideal Industries
LANTEK User Manual - Ideal Industries
LANTEK User Manual - Ideal Industries
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Chapter 3<br />
Structured Cable Field Calibration and Testing<br />
Power Sum NEXT and Power Sum ELFEXT<br />
Power Sum tests measure the crosstalk effects of three transmitting pairs on the<br />
fourth pair in the same cable sheath.<br />
1<br />
2<br />
3<br />
6<br />
4<br />
5<br />
7<br />
8<br />
Effects of<br />
3 Pairs on 1 Pair<br />
During the Power Sum NEXT test, six measurements are made at each end of the<br />
cable and combined (pairs 1-2, 3-6, and 4-5 vs. pair 7-8, etc.) for a total of eight<br />
measurements.<br />
2<br />
1<br />
6<br />
3<br />
5<br />
4<br />
8<br />
7<br />
Figure 3-14: Power Sum NEXT Test Screen<br />
During the Power Sum ELFEXT test, twelve measurements are made at the DH side of<br />
the cable and combined (pairs 1-2, 3-6, 4-5 vs. pair 7-8, etc.) for a total of four<br />
measurements.<br />
Figure 3-15: Power Sum ELFEXT Test Screen<br />
Note: Power Sum NEXT measurements will generally read 2 - 3 dB lower in value<br />
(higher crosstalk) than conventional NEXT.<br />
3-25