Monday, June 2, 2008

How to Make CAT5e Patch Cables

Below is a small portion of the ComputerCableStore.com Guide "How to Make CAT5e Patch Cables". Please visit the ComputerCableStore.com to find the full artical.


We will discuss Materials needed, cable Preparation, as well as connector Termination. The first step to start building patch cables is ordering the correct materials. The first and most important material will be the cable we'll be using. CAT5e is available in a variety of different types: StrandedStranded is primarily used for building patch cables. The core of the conductors is comprised of many strands of copper so that it can be flexed repeatedly without the copper cores of the conductors breaking. SolidSolid CAT 5e is primarily used for in wall/permanent applications. The copper cores of the conductors are comprised of one single solid strand of copper. This allows the cable to carry signals over longer distances but due to the fact that it has solid copper conductors it can not be flexed too many times without the copper cores breaking. PlenumPlenum is primarily used for in wall/permanent applications where the local building codes require that plenum cable be used. Plenum cable is essentially the same as solid except the jacket is comprised of a PVC Teflon mix. This plenum jacket on is a low smoke/flame retardant jacket that reduces the amount of toxic fumes that are released into air when the jacket is burned. Stranded is best when building patch cords. The flexible stranded cores will hold up best against the daily abuse that these cables tend to endure. We carry Stranded Category5e in a variety of colors to suite your particular needs.

Step 1: Before we start building a patch cable you will need to cut a length of stranded CAT5e. When cutting the length you should make sure to measure. Nothing is worse than the patch cable you just built being an inch too short for your application. After cutting the desired length we will start building our cable by stripping back approximately 1 inch of the jacket. We use Ideal's 45-165 Coaxial Stripper for this purpose. When striping back the jacket make sure that the depth of your stripper is set deep enough to cut the jacket but not so deep that it nicks the conductors. If you do nick the conductors while stripping the cable, the cable may work fine at first, but after time the conductors will break, or even worse, begin to short out.



Step 2: Now that we have the jacket stripped back we'll want to separate and straighten the pairs. We'll start by pulling the first pair and the last pair to their respective sides (Orange to the left and Brown to the right). Untwist these pairs making sure not to untwist the cable any further than you've stripped back the jacket. Now we'll split the green pair. Pull the white/green conductor to the left and the green conductor to the right. This leaves you with the blue pair in the middle. Untwist the blue taking care to ensure that the white/blue conductor is on the left and the blue conductor on the right.Note: Normally, it would be unmentionable to untwist the CAT5e pairs, except when building patch cables. It would be almost impossible to insert the conductors into the proper connector locations without untwisting. (Keep in mind you want to keep as much of the twist of each pair intact in order to meet performance standards.)



Step 3: Now that we've separated and straightened the pairs we need to arrange the conductors in the proper order according to which wiring standard you are using. For this example we will be wiring via the 568-B standard (most common in patch cables). Please consult the pin-out for the proper color codes. After you have the wires arranged, place them tightly together as show in the picture to the right. Once this is done, verify that the wires are still in the proper order and continue to step 4.


Step 4: Now we need to trim the conductors down to fit into the RJ45 connector. While trimming, make sure you make a nice clean cut at a 90 degree angle about 1/2 of an inch from the end of the jacket. If you fail to make a straight cut, some of the conductors may not reach the connector contacts. If you cut the conductors too short, again they will not make contact. If you leave the conductors too long, when crimping the connector, the jacketing will not be gripped leaving the strain on the conductors. This is not a good situation! For proper trimming, hold the wires securely just at the end of the jacket as shown in the picture to the left. Be sure to keep the conductors in the proper order.