Cisco Systems uBR7225VXR Network Router User Manual


 
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Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
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Chapter 4 Connecting the Cisco uBR7225VXR Router to the Cable Headend
Measuring the RF Signal at the Forward Test Point on a Laser Transmitter
Figure 4-47 Downstream Forward Test Point on the Laser Transmitter—Digital Channel Display
Step 6 Go to the main menu on the spectrum analyzer and advance the screen displays (next screen) until the
digital channel power display is shown. (See Figure 4-48.)
Figure 4-48 Downstream Forward Test Point on the Laser Transmitter—Digital Channel Power
Display
Note The +3.6 dBmV digital power rating is nearly the same as the previously measured video carrier level
(+4.3 dBmV). This value is too high to provide reliable digital data transmission.
Step 7 Set the upconverter output level so that the amplitude of the digitally modulated carrier is 6 dB to 10 dB
below the amplitude found on the same frequency on an analog TV channel.