Alcorn Mcbride V+ series, Руководство пользователя

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8-14 V16+ Hardware Reference
Video Synchronization
The V16+ is designed to extract the vertical frame clock from an external video
sync signal. This signal should be NTSC or PAL composite video at the
standard sync level of 4.1 volts peak-to-peak.
The sync signal is connected to the V16+ via a rear panel BNC connector. If
additional devices are to be wired to the same sync signal, a BNC “T” may be
used to daisy-chain the signal. If the V16+ is the last device in the chain, the
internal 75-Ohm terminator should be connected
(factory default) ; otherwise it
should be disconnected.
A common sync connection scheme is to use the “Gen” output of a player to
drive the “C-Sync” inputs of another player, with the second “C-Sync”
connector of that player connecting to a third, and so on. The final player’s
second “C-Sync” connector would go to the V16+, which should have its
terminator enabled.
The V16+ may also work with “Black Burst Sync”, if its level is high enough.
Black burst sync is generally provided not at sync level, but at video level
(approximately 0.7 volts peak-to-peak). Signals at this level should
not be
terminated with the 75-Ohm terminator. If you are trying to use a video level
signal, have the terminator disconnected, and still can’t get the sync to work
reliably, it is possible to increase the V16+ input sensitivity by removing R16.
Since this procedure is performed with wire cutters, it should not be undertaken
lightly. It also voids the warranty. But if it’s 3 AM in Abu Dhabi and your
show opens at dawn, what the heck.
Sync Termination
Composite sync signals contain high frequency components. When the signal
reaches the end of the line it has a tendency to reflect back toward the sync
generator. This reflected signal is undesirable because it degrades the “real”
signal. To prevent signal reflection, a terminating resistor is usually placed at
the end of the line.
The V16+ provides an internal 75-Ohm terminating resistor. The unit is shipped
from the factory with termination enabled (jumper installed).

Configuring sync termination
1. If the V16+ is the last unit in the daisy-chain, verify that W3 is present.
2. If the V16+ is NOT the last unit on the daisy-chain, remove W3.