12
16-PORT TYPE 3 MAU
1.3.2 T
YPE
3 C
ABLE
The Type 3 cable used with the MAU should be standard twisted-pair
telephone building wire. Recommended wire gauge is 24 or 22 AWG, Belden
9562 or equivalent. The following requirements should be met:
• Solid copper twisted pairs, with at least two twists per foot
• A maximum DC resistance of 28.6 ohms per 1000 feet
• Characteristic impedance:
- 90 to 120 ohms at 256 kHz
- 87 to 117.5 ohms at 512 kHz
- 85 to 114 ohms at 772 kHz
- 84 to 113 ohms at 1000 kHz
• Maximum attenuation per 1000 feet:
- 4.00 dB at 256 kHz
- 5.66 dB at 512 kHz
- 6.73 dB at 772 kHz
- 8.00 dB at 1000 kHz
NOTE
Commonly available consumer telephone cable, sometimes called “flat
cable” or “silver satin,” should not be used. This type of cable can
drastically reduce the cable lengths possible in your network. Exceptions
to this are the patch cables used to connect MAUs in the same wiring
closet in 4 Mbps networks; they may be made of this type of cable, but
they should be no more than three feet in length. In 16-Mbps networks,
however, silver satin of any length should not be used.