Making Your Own UTP Cables
You will need the following tools and supplies to build your own Ethernet cables (see Figure 1):
- UTP cable (Category 5 or better)
- RJ-45 connectors
- Wire stripper
- RJ-45 crimping tool
Figure 1 You'll need wire strippers, crimping tool, UTP cable, and RJ-45 connectors to make your own 10BaseT (100BaseT) cables.
You can buy all of the above for a single price from many different network-products vendors. If you are working with a network with a wiring closet, you will also want to add a punchdown tool to your kit.
Before you make a "real" cable of any length, follow the procedures below and practice on a short length of cable. RJ-45 connectors and bulk cable are cheap; network failures are not.
Follow these steps for creating your own twisted-pair cables:
- Determine how long your UTP cable should be. You'll want to allow adequate slack for moving the computer and for avoiding strong interference sources. Keep the maximum distances for UTP cables listed later in this chapter in mind.
- Roll out the appropriate length of cable.
- Cut the cable cleanly from the box of wire.
- Use the wire stripper to strip the insulation jacket off the cable
to expose the TP wires (see Figure
2); you'll need to rotate the wire about 1-1/4 turns to strip away all
the jacket. If you turn it too far, you'll damage the wires inside the cable.
Figure 2 Carefully strip the cable jacket away to expose the four wire pairs.
Don't strip the UTP wires themselves, just the jacket!
- Check the outer jacket and inner TP wires for nicks; adjust the stripper tool and repeat steps 3 and 4 if you see damage.
- Arrange the wires according to the EIA 568B standard listed earlier
in "EIA/TIA 568B TP Standard" (see Figure
Figure 3 Arrange the wire pairs for insertion into the RJ-45 connector according to your chosen scheme (EIA for instance).
- Trim the wire edges so the eight wires are even with one another
and are slightly less than 1/2 inch past the end of the jacket.
If the wires are too long, crosstalk (wire-to-wire interference) can result;
if the wires are too short, they can't make a good connection with the RJ-45
plug (see Figure 4).
Figure 4 An even trim and proper stripping of the UTP cable is essential to a good RJ-45 cable.
- With the clip side of the RJ-45 plug facing away from you, push
the cable into place (see Figure
5). Verify that the wires are arranged according to the EIA/TIA 568B standard
before you crimp the plug onto the wires. Adjust the connection
Figure 5 Push the RJ-45 connector into place, ensuring the cable pairs are ordered properly.
- Use the crimping tool to squeeze the RJ-45 plug onto the cable
(see Figure 6).
The end of the cable should be tight enough to resist being removed by hand.
Figure 6 Firmly squeeze the crimping tool to attach the connector to the cable.
- Repeat steps 4-9 for the other end of the cable. Recut the end of the cable if needed before stripping it.
- Label each cable with the following information:
- Wiring standard
- End with crossover (if any)
- _______________ (blank) for computer ID
The cables should be labeled at both ends to make matching the cable with the correct computer easy and to facilitate troubleshooting at the hub. Check with your cable supplier for suitable labeling stock or tags you can attach to each cable.
Scott Mueller has sold more than two million copies of his best-seller Upgrading and Repairing PCs since it became an instant classic in 1988. Scott's industry-defining hardware book has been translated into 11 languages and has received accolades from PC technicians, enthusiasts and students worldwide. Scott is president of Mueller Technical Research, an international research and corporate training firm. Since 1982, MTR has specialized in the industry's longest running, most in-depth, accurate and effective corporate PC hardware and technical training seminars, maintaining a client list that includes Fortune 500 companies, the U.S. and foreign governments, major software and hardware corporations, as well as PC enthusiasts and entrepreneurs. His seminars have been presented to thousands of PC support professionals throughout the world. Scott has developed and presented training courses in all areas of PC hardware and software. He is an expert in PC hardware, operating systems, and data-recovery techniques. For more information about a custom PC hardware or data recovery training seminar for your organization, contact Lynn at
If you have questions about PC hardware, suggestions for the next version of the book, or any comments in general, send them to Scott via email at mailto:email@example.com. When he is not working on PC-related books or teaching seminars, Scott can usually be found in the garage working on performance projects. This year a Harley Road King with a Twin-Cam 95ci Stage III engine continues as the main project (it's amazing how something with only two wheels can consume so much time and money ), along with a modified 5.7L '94 Impala SS and a 5.9L Grand Cherokee (hotrod SUV).
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