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Example Twisted Pair Cable Traces
The following are examples of both good and faulted twisted pair cables.
Good 370ft (112.8m) twisted pair cable with open end – Figure 3-30. Some
noise is showing on the trace as un-terminated cable un-shielded cable is also an
antenna.
Figure 3-30
Same 370ft (112.8m) section of cable with a short at the far end – Figure 3-31
Note: The short also caused and increase in the noise on this pair due to local
EMI environment. Using the Noise Filter in the Trace menu will eliminate the
trace’s fuzzy appearance.
Figure 3-31
Twisted pair with a good splice – Figure 3-32. The minor impedance bump is
due to the small amount of untwist of the pair to make the splice.
Figure 3-32