Atec Acterna-DSAM-6000 - Manual (Page 7)

Sweep
Service quality depends on transmitting signals with the best noise specifications
and the lowest intermodulation distortion. The majority of all transmission er-
rors, including digital, can be detected by measuring the frequency response of the
network. A sweep trace reveals every physical error in the network that influences
the transmitted signals. Also, since sweep results are independent of transmission
methods and formats, it is the most effective and efficient method for technicians
to set up the right gain versus frequency.
Sweepless Sweep® Mode
For fundamental alignment of the forward distribution network, the JDSU
Sweepless Sweep mode provides an economical solution. This mode scans the
entire forward spectrum, displaying all levels across all frequencies (as defined by
meter configuration). The technician adjusts the reception of the node amplifier
with this scan and then normalizes the display by saving a reference. The resultant
display is a flat zero level trace. When the measurement point is moved to the
output of the RF amplifier, any changes due to the amplifier will be displayed as a
deviation (delta) from the reference display. The same reference is used as the
technician moves down the cascade, thus providing an excellent tool to align
succeeding amplifiers to compensate for the effects of each cable segment. To
isolate the effects of headend changes in levels, or to align portions of the
spectrum where there are no active carriers to reference, the forward sweep option
should be considered.
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DSAM-6000 DIGITAL SERVICE ANALYSIS METER
Sweepless Sweep provides a quick method to check
cable system integrity using active channels to sweep
the forward path. Sweep points do not need to be
added and no forward path headend gear required.
Forward Combiner
Out
SDA-5500
SDA-5510
SDA-5000
DSAM-6000
Out In
In
Splitter
Headend or Hub Site Distribution Plant
Optical
Transmitter
Optical
Transmitter
Optical
Transmitter
Reverse Combiner
Optical
Transmitter
Node
Node
Node
Optical
Transmitter
Optical
Transmitter
FORWARD SWEEP
Meter receives sweep pulses and reference
levels transmitted from headend or hub site and
displays difference levels (delta).
RETURN SWEEP
Meter generated sweep pulses transmitted from field and
received in headend or hub site.
RETURN SWEEP
Headend or hub site transmits received sweep pulse levels back
to originating field meter for display of difference levels (delta).
The DSAM-6000 and the SDA-5000 perform
both forward and reverse sweep functions. *
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