Consonics CyberTek Qualifier, Руководство пользователя

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Qualifier Supplement
6
Theory of Operation
A cable television system distributes signals by a cable suspended on utility poles or by a
cable buried in the ground. A combination of both methods is not uncommon. From the
main distribution cable, a device called a local tap is used to interface the distribution system
cable to the subscriber. From one to eight and possibly more subscribers may be served from
a single local tap location. A multitude of local taps is used through out the distribution
system to provide cable services to subscribers.
From the local tap in overhead systems a drop cable is suspended from the local tap and
secured to the residence at a safe distance from the ground. The drop cable is routed down
the side of the residence to a device called a ground block. The ground block is a pass
through device connected to an earth ground. It is used to prevent static build up between the
cable system and the electrical power wiring of the residence. Thereby reducing the risk of
electrical damage to devices within the residence that are connected to cable system.
From the ground block the cable enters the residence and is routed to the device/s within the
residence. The cable within the residence may be split (branched) into a multitude of paths
supplying cable services to many locations within the residence. Examples of devices
connected to the internal cabling are television sets, VCRs, cable modems, digital carrier
receivers, and special service transceivers.
Typical CATV overhead routing to private residence.
Drop Cable
Ground Block
Private Residence
CATV Distribution System
Local Tap
Upstream Path
Downstream Path