Change 1, 30 November 1996
Screened UTP. CAT 5 100 ohm UTP is available with a
grounded screen for additional EMI containment or rejection. Unique
eight-pin modular plugs and jacks are required to provide a path for
the ground circuit between the workstation and the network equipment.
Coaxial Cable. Fifty ohm coaxial cable is not normally
recommended for new construction, but may exist in refurbished
buildings where existing Ethernet electronics are to remain. If
existing 50 ohm coaxial systems are to be modified, the RCDD should
consult the original equipment manufacturer (OEM) for: recommended
maximum cable lengths, approximately 200 m (600 ft.); minimum
distances between drops, approximately 2.5 m (8 ft.) and the maximum
number of drops per run (approximately 28) prior to modifying any
coaxial runs. Connection of equipment designed for unbalanced
coaxial distribution cable to a balanced UTP network requires the use
of a BALUN device.