Cisco 7246 - uBR Router Hardware Installation Manual page 117

Chapter 4 Connecting the Cisco uBR7200 Series Router to the Cable Headend
Figure 4-20
Change the spectrum analyzer settings to view the digital channel power. This setting enables you to see
Step 7
if there is too much power on the upconverter output. In
+64.31 dBmV, which is beyond the DOCSIS-specified range of +50 to +61 dBmV.
Tip A spectrum analyzer might become overloaded and produce false readings (such as internally generated
spurs) when measuring a signal at this amplitude.
Figure 4-21
Adjust the power on the upconverter output to ensure that it is between +50 and +61 dBmV. In
Step 8
Figure
OL-5421-03
Measuring the RF Signal at the Upconverter Output—Overload Condition Corrected
with Attenuation
Measuring the RF Signal at the Upconverter Output—Upconverter Output Level Too
High
4-22, the upconverter output is reading +57.06 dBmV, which is within the correct range.
Cisco uBR7200 Series Universal Broadband Router Hardware Installation Guide
Measuring the Downstream RF Signal
Figure 4-21, the upconverter output is reading
4-21