Chapter 10
Measure Mode – Spectrum Tab
Spectrum Measurement Modes
248
DSAM Help User Guide
Rev. 001
Spectrum Measurement Modes
High levels of ingress noise enter a CATV system through damaged or
otherwise improperly shielded coaxial cable or related components.
Ingress can reduce signal quality and prevent an effective installation.
The Spectrum tab provides Upstream Spectrum, Downstream Spec-
trum, Field View, and Ingress Resistance measurement modes that
analyze CATV channels.
Upstream
Spectrum
Surveys and analyzes ingress and distortion on the upstream path
(return path). It can be used to identify the frequency at which ingress
occurs and displays the level value. This level measurement can be
checked in relation to a user-configured limit to determine a pass or fail
status.
Downstream
Spectrum
(additional purchase required) Surveys the entire CATV downstream
spectrum frequency range (4 MHz to 1 GHz) in 50 MHz frequency
spans with a dynamic range of 60 dB.
Field View
(additional purchase required) Analyzes and displays ingress and
distortion on the upstream path (return path) as viewed by PathTrak or
Phasor system at the node and the headend. It identifies the frequency
at which ingress occurs and displays the level value.
Ingress
Resistance
Allows for a 20 MHz fixed span. Within each frequency span, the
DSAM forms and continuously updates a graph with 201 frequency
points. The total Downstream Spectrum frequency range extends from
88 MHz to 108 MHz.
Upstream Spectrum
The Upstream Spectrum measurement mode surveys and analyzes
ingress and distortion on the upstream path (return path). It can be
used to identify the frequency at which ingress occurs and displays the
level value. This level measurement can be checked in relation to a
user-configured limit to determine a pass or fail status. You can save
test results for later reference.
21128026 R001 DSAM Help User Guide.book Page 248 Thursday, February 5, 2009 2:02 PM
