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Cisco CVA122/CVA122E Hardware Installation Guide
OL-0799-02 (05/2001)
Chapter 2
Preparing for Installation
Site Requirements
Caution
If you replace a connector, be careful not to score the center conductor. A scored conductor
can reduce or impair performance for channels broadcast between 550 and 860 MHz. If
the center conductor is too short, signals between 5 and 42 MHz might be affected.
Distance Limitations
The size of your networks and the distances between connections on the CATV network can affect the
successful installation of a Cisco CVA122/CVA122E Cable Voice Adapter, which must be within 100
miles of the CMTS. This distance can also be defined in relation to the speed of light through the
transmission network as being less than 2 msec from the CMTS to the Cisco CVA122/CVA122E Cable
Voice Adapter and back again.
Note
Exceeding this distance is a violation of the DOCSIS RFI specification.
When preparing a site for network connections to the Cisco CVA122/CVA122E Cable Voice Adapter,
consider the following:
•
The number of amplifiers from the installation site to the nearest node
•
The number of outlets and amplifiers at the installation site
•
Cable pinouts if you plan to build your cables
Potential distance limitation problems in the CATV network can be reduced by doing the following:
•
A correct, linear unity gain two-way sweep procedure is in place
•
Industry-standard configuration practices are used at the headend
•
The downstream frequency is known at the time of installation
•
The absolute downstream signal level can be measured where it enters the cable voice adapter
