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STP Connector Characteristics
The near-end crosstalk and insertion loss specifications below are intended to extend
the specifications in ANSI/IEEE 802.5 when the connectors are to be used with a
cable that meets the Type 1A, 2A, and 6A specifications described above.
Near-End Crosstalk (NEXT)
Near-end crosstalk is a measure of signal coupling from one circuit to another within a
connector, and is derived from swept frequency voltage measurements on short
lengths of Type 1A STP test leads terminating at the connector under test. A
balanced input signal is applied to a disturbed pair of the connector while the induced
signal on the disturbed pair is measured at the near end of the test leads.
The near-end crosstalk of any pair must not exceed the values listed in the following
table.
Table 29. Near-End Crosstalk for the 150-ohm STP Data Connector
Frequency
100 kHz
1 MHz
4 MHz
8 MHz
10 MHz
16 MHz
20 MHz
25 MHz
31.25 MHz
62.50 MHz
100 MHz
300 MHz
11.89 to 300 MHz
Note:
≤
#NEXT(f) NEXT(16)
(f) in MHz
dB
−65
−65
−65
−65
−65
−62.4
−60.5
−58.5
−56.6
−50.6
−46.5
−36.9
see #
f
20
+
log
------ -
16
Chapter 5. Planning for Twisted Pair Cable Connections
47
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