When selecting cables for video, either RCA, BNC coaxial cable or Category 5 twisted pair cable can be used. BNC cables generally have lower losses than RCA, are more rugged, and are most commonly constructed using coaxial cable, such as the one which runs in your home to connect with the cable company. This type of cable is referred to as RG-58 and RG-59. RG-58 cable is lighter and more flexible that RG-59, but has a little more loss at higher frequencies. The BNC connectors are usually molded onto the cable end. Standard pre-made cable lengths are 3', 6', 10', 25', 50',100', 150' and in bulk come in rolls of 500' or 1,000'. Although RG-58/-59 cable is great stuff, it's relatively heavy and may be awkward. With the advent of video baluns (a small lipstick size device) you can now run video and power over a Category 5 cable. The Category 5 cable also known as Cat5 carries four pairs of wires allowing for more runs on a single cable and being much lighter is easier to work with. While distances beyond 500' becomes a video signal problem for BNC, Cat5 can comfortably extend out to 1,000' and with “active” video baluns that distance can be increased to 10,000'. Much debate is made as to whether BNC or Cat5 produces a better signal.
There are many grades of RCA cables available, some intended for audio, some for video, and some for both. RCA cables are usually thinner and not as rugged as BNC cables. For cable lengths under 20 to 25 feet, most RCA cables provide acceptable results for both audio and video but you will rarely if ever see professionals use RCA. At lengths of as little as 30 feet, RCA cable can start to show a measurable loss at the higher frequencies, depending on the quality of the cable. RCA cables usually have molded connectors at the cable ends and the connectors themselves may come with tin plating (standard) or with gold. The gold looks nice, but is really not necessary for a good, reliable connection.
Coaxial Cable A type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference.
Coaxial cabling is the primary type of cabling used by the cable television industry and is also widely used for computer networks and CCTV. Although more expensive than standard telephone wire, it is much less susceptible to interference and can carry much more data.
Plenum Cable
A type of cable that is run in the plenum spaces of buildings. In building construction, the plenum (pronounced PLEH-nuhm) is the space that is used for air circulation in heating and air conditioning systems, typically between the structural ceiling and the suspended ceiling or under a raised floor. The plenum space is typically used to house the communication cables for the buildings CCTV, computer and telephone network(s). However, use of plenum areas for cable storage poses a serious hazard in the event of a fire as once the fire reaches the plenum space there are few barriers to contain the smoke and flames. Plenum cable is coated with a fire-retardant coating (usually Teflon) so that in case of a fire it does not give off toxic gasses and smoke as it burns. Twisted-pair and coaxial versions of cable are made in plenum versions.
RJ45 Connector vs. RJ11 Connector
Cat-5 Cable
A
network cabling that consists of four twisted pairs of copper wire terminated by RJ45 connectors. Cat-5 cabling supports frequencies up to 100 MHz and speeds up to 1000 Mbps. It can be used for 1000Base-T, 100Base-T, and 10Base-T networking.
Computers hooked up to LAN s are connected using Cat-5 cables, so if you're on a LAN, most likely the cable running out of the back of your PC is Category 5.
RJ45 Connector
Short for Registered Jack-45, an eight-wire connector used commonly to connect computers onto a local-area networks (LAN), especially Ethernets. RJ-45 connectors look similar to a telephone line connector ( RJ-11 connector), but they are somewhat wider.
RJ-11 Connector
Short for Registered Jack-11, a four- or six-wire connector used primarily to connect telephone equipment in the United States. RJ-11 connectors are also used to connect dial-up modems to the internet using your telephone line.
