Extron Electronics SEQ 100 15HD User Guide - Manual (Page 4)

VersaTools ® SEQ 100 Skew Equalizer
Chapter One • Introduction ..................................................... 1-1
VersaTools ® SEQ 00 Skew Equalizer
Introduction
The manufacturing process for network (CAT 5e) UTP cable
leads to a condition called pair skew. The Extron SEQ 100 15HD
Skew Equalizer corrects skew delay (misconvergence) problems
commonly encountered when using Category (CAT) 5, 5e, or 6
twisted pair (TP) cables for RGB video transmission. The
equalizer can also be used to correct for skew problems in
component video transmission systems. The SEQ 100 15HD
inputs and outputs video on 15-pin HD female connectors.
N An SEQ 100 skew equalizer should not be necessary
when Extron Enhanced Skew-Free A/V UTP cable is
used.
Skew equalization
Skew exists between pairs when the physical length of one
wire pair is different from another. As the transmission cable
length increases, the amount of skew increases. Skew affects the
displayed image when the differential length between wire pairs
exceeds 2 feet, causing the timing of the red, green, and blue
video signals to appear out of alignment (horizontal registration
errors). The signals transmitted on the shortest pair are shifted
to the left if using white lines on a black background. A white
vertical line on a black field can appear as individual red, green,
and blue lines that are close together; the signal transmitted on
the shortest wire pair leads the other colors and appears to the
left on the display.
The skew equalizer provides three separate time delay circuits,
on the red, green, and blue video lines. Each time delay circuit
can be independently adjusted, from 0 to 39 nanoseconds, to
properly align the red, green, and blue video signals on the
displayed image.
The SEQ 100, installed in a TP transmission system and correctly
set, delays the video signal, red, green, or blue, on the shortest
wire pair to properly converge the displayed video image. The
skew equalizer can be connected between the TP transmitter
and its video source or between the TP SEQ and its connected
display device, whichever is more convenient. Figure 1 shows
the SEQ 100 installed on the SEQ output, which is the typical
configuration.
N You should not connect the SEQ between the TP
transmitter and a source if you are also connecting a
local monitor.