C-COR Flex Max901e, Руководство по эксплуатации оборудования

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5
1502154 Rev D Configuration 5-21
Single Person Return Balancing Procedure
Single person return balancing requires the use of more sophisticated equipment than does two
person return balancing. Figure 5.10 shows the typical single person configuration of the test
equipment used in the single person return balancing procedure.
For single person return balancing, proper balancing of each unit depends on all preceding units
being properly balanced. It is particularly critical that the first amplifier or node be balanced
correctly since, if balanced incorrectly, all succeeding units will also be affected. For this reason,
when initially balancing, start at the unit closest to the headend and work outward.
Because these are sweep systems, ingress may effect the outcome. Terminating return ports or
keeping all amplifiers terminated until activation will limit ingress. Standard sweep equipment also
has a “noise/ingress” feature that can be used for troubleshooting. This displays the noise seen in
the headend.
Tech Note TD0079 provides the generalized procedure using Wavetek Stealth
®
equipment
(3ST/3HRV and 3SRV), Hewlett-Packard CaLan equipment (3010H and 3010R), and the method
using relatively inexpensive video equipment (spectrum analyzer, signal generator, video camera,
video signal modulator, and TV monitor). For specific instructions on operation of this equipment,
refer to the manufacturer’s user manual.
Figure 5.10
Typical
Configuration of
Single Person Return
Balancing
Equipment
Note If a unit closer to the headend is balanced incorrectly, all succeeding amplifiers
will not be balanced correctly using the single person method.
➊
A handheld sweep
device transmits a signal to
the headend through the
return path of the amplifier
being balanced.
➋
A device (usually rack
mounted) at the headend
analyzes the incoming signal
and transmits the results back to
the handheld unit.
➌
The handheld unit receives
the data from the headend unit
and displays an image of the
signal as it would appear at the
headend.
Headend
Flex Max901e