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SDA-5500/SDA-5510 Sweep Configuration: Sweep History and Theory
298
14
Fig. 14-21 Connecting an SDA-5510 in a System with an
SDA-5500
What is sweep testing, and why do it? The most accurate way to align a
cable network for either forward or reverse services is to sweep the system.
Sweeping consists of measuring the frequency response over the bands that
the system is designed to carry, plotting level versus frequency. The goal of
a cable distribution network is to provide unity gain (or some other fixed
value) from all inputs to all outputs at all frequencies.
By testing throughout the band, instead of at a limited number of pilot
frequencies, sweeping detects many problems. Used efficiently, a sweep
system can detect "suckouts" and other narrow frequency irregularities.
Forward Sweep Theory
The primary goal of a sweep system is to accurately measure a cable
system's frequency response. Sweeping accomplishes this by injecting a
sweep of frequencies at the input to the system, and then measures the
level of each frequency at the output of the system.
SDA-5000
Nodes
Reverse Node
Combiner
Forward Combining
Network
in
out
in
out
SDA-5510
SDA-5500
SWEEP HISTORY AND THEORY
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