Description and Basic Operation: Basic Modes of Operation
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create a sweep response without injecting any sweep pulses. This
guarantees that no subscriber interference will result from your sweep
testing.
• SDA sweep: SDA sweep operates identically to Stealth sweep, but it is
much faster! It is also critical to note that, for SDA sweep to work, you
must be using SDA equipment both in the headend and in the field.
• Stealth reverse sweep (OPT1): Reverse sweep uses sweep carriers
from a field unit that are sent back to the headend transmitter and
measured to calculate return path frequency response. Stealth offers a
high level of flexibility in setting frequencies and levels to give you the
maximum flexibility in sweeping a return path network without creating
any service interruptions.
• Aligning reverse amplifiers (OPT1): This alignment mode is tailored to
set the gain and tilt of reverse amplifier units. Using the SDA-5500 or
SDA-5510 headend sweep transmitter, this screen shows the absolute
signal levels at two selected frequencies and calculates the gain and tilt
of a return path system. All the information a technician needs to set up a
reverse amplifier or node is displayed in one location.
• Sweepless Sweep: Sweepless Sweep allows you to get sweep
information even if no transmitter is available. If a transmitter is down, or
if something is blocking the telemetry channel, Sweepless Sweep can
still be used. In Sweepless Sweep, the SDA field unit measures the
stable carrier levels, memorizes them, and establishes a reference.
These levels can then be compared with the levels of the same carriers
at a different point in the network, and the differences in frequency
response can be highlighted.
• Loopback Sweep (OPT2): The full sweep local Loopback test enables
you to perform a rough frequency response, gain, and loss test on active
and passive devices in the field using a single meter.
See Also
½ Chapters 4, Field Sweeping with the SDA-5000, and 13,
SDA-5500/SDA-5510 Sweep Configuration, together
provide a complete description of the SDA family’s sweep
capability.
Proof-of-Performance Measurement Tools
The SDA-5000 provides an extensive suite of tools for troubleshooting and
for performing proof-of-performance tests. Carrier-to-noise, hum, and depth
of modulation are all calculated on unscrambled analog video channels in-
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