Crimping Cat5 Delema

[MPETNUCH]

I just got in bulk 200 yards of cat5 cable for less than 40 dollars. I borrowoed a crimping tool and bought some RJ45 heads but the damn blaster wire wont work. Is their anythign speical I have to do to the wire. I stipped the outer cover but I left the colored part of the individual wieres on. Do I have to stip that too? Thanks for the help.

[Waffle_King]

No, definitely do not strip the inner insulation.

First strip about an inch of the outer insulation, and then cut he wires down all to the same length. Hold it up against the head to make sure that the wires can go up to the end of the head, and that the outer insulationwill be getting crimped.

Then line the wires up so that they are alternating. There will be four colors, two of each, one full, and the other white with a little splotch at the end. You need to line these up in a pattern, and then have that same pattern at the other end

Next, jam the wires up into the head, making sure that they all go neatly into their respective "lanes" and crimp it tightly. The outer insulation should be inside the head.

sorry if that is kind of garbled, it is one of those things that is easier to do than to say.

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10 minutes, 6 monkeys

[BigBlockMopar]

Next, jam the wires up into the head, making sure that they all go neatly into their respective "lanes" and crimp it tightly. The outer insulation should be inside the head.

sorry if that is kind of garbled, it is one of those things that is easier to do than to say.

There are two basic styles of RJ-45 connector, and they're both likely to be available at your local electronics shop. Where the cable enters, there's a flat kind for use with flat telephony cable - this kind of connector can work in a pinch, but avoid buying them because the flat kinds don't offer enough strain relief when you're dealing with round twisted-pair. You want the kind with a slightly oval cable opening in the back.

And gold-plated contacts. Gold doesn't oxidize. Spend the extra for them. In fact, I think it's part of the ethernet standards, but I've seen lots of round RJ-45s for UTP without gold contacts.

Oh, yeah, and it takes practice. Make sure that you have *lots* of spare RJ-45 connectors your first time. If you're dealing with 10base-T exclusively, you can get away with using only two pairs, 1-2 and 3-6; until you're good at them, you could stick with those. 100base-T won't work over two pairs.

100base-T also requires *bonded* twisted pairs, where the wires that make up a pair are bonded to each other. For short runs, though, the minimal impedance difference made by the uniform control of stray capacitance probably won't make a difference; just be aware of it.

Here's a pinout for you:

http://www.pin-outs.com/datasheet_22.html

[ndelo]

What do you mean by bonded pairs? I've been running CAT 5 at work and have seen, in the existing cable, both 2 pair and 4 pair wire. I've been sticking with 4 pair for my runs but am not sure what you mean by bonded pairs. I am a newbie to running cable, if there is such a thing--I was asked to wire half our building (small building) sometime last year and had no prior know-how--so any help or tips I can get on the best cable/connectors to get the best throughput would be great.

[FoBoT]

Originally posted by BigBlockMopar:
Oh, yeah, and it takes practice

for anyone that hasn't done this before, this is the key, it is more art than science. some people get real good at putting on rj-45 ends and some never get the hang of it.

practice, practice, practice

and if you have a tester available to make sure they are correct it helps

[Waffle_King]

yeah, after doing it many times, both at school, and at home, I have gotten quite good at it.
maybe that because at school, I wasn't paying for the rj-45 heads...

speaking of which, a nice crimper is a must, the one I had at school was the cadillac of crimpers, it was big, heavy, had a beautiful ratcheting action, and got a nice tight fit. The other one was alot flimsier, not ratcheting, and just didn't work as well.

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10 minutes, 6 monkeys

[Fandelem]

*shrug* my crimper costed 15 bucks and it never fails me ;b it even has a cool razor blade on it that i've cut myself numerous times *smirk*

[BigBlockMopar]

Originally posted by ndelo:
What do you mean by bonded pairs?

Just that. The wires of each pair are bonded together, like a very small appliance cable; of course, this is with the twist in them.

The reason for this is that it ensures that both wires in the pair are held closer together, rather than splitting a few thousandths of an inch apart when the cable is snaked around a corner or something.

When you're forcing a signal down UTP at the speeds of 100 megabit ethernet, let alone the more and more popular gigabit, this becomes more of an issue.

This stuff is known as Cat 5E ("enhanced"), which provides longer runs at 100base-T. The gigabit standard is known as Cat 6. If I was running a cable through an existing cable tray to the hub, I'd run Cat 5. If it was a really long way away, I'd run Cat 5E. And, if I was lifting suspended ceiling tiles to put the cable in, I'd plan to use Cat 6.

I've been running CAT 5 at work and have seen, in the existing cable, both 2 pair and 4 pair wire. I've been sticking with 4 pair for my runs but am not sure what you mean by bonded pairs.

Okay. To be clear. Cat 3 and Cat 5 only use two pairs, four wires, but have more than that.

Technically, Cat 3 is rated for 10base-T, or 10 megabits/second.

There's been a lot of confusion over new 100 mbps standards, and a couple of the proposals required 4 pairs - 8 conductors - to achieve that speed. While 100base-T actually only requires 2 pairs, it's practice to support and terminate the extras inside the RJ-45.

In fact, I suspect part of the reason that Cat 3/5 include the two unused pairs is for the same reason that your telephone wall jack includes 4 conductors, though only two are needed: it's a pain in the *** to have to run a replacement wire, so you include spare pairs. Most of the cost in cabling is the labor to put it there, so a few extra conductors is a good investment. Several of the proposed 100 mbps ethernet standards used them.

Cat 5E and 6, like Cat 3 and 5, appear to maintain that principle, though I don't know if gigabit ethernet actually uses 4 pairs. I'd suspect that it does.

But Cat 5E and 6 cables each have four bonded pairs of twisted wire. They're also a smaller diameter (lower gauge) of wire; while it increases the resistance of the conductors, it lessens the effects of stray capacitance within a pair and between adjacent pairs.

This makes it a lot tougher to assemble. I very highly recommend that you get *good quality* cables and connectors, and ditch the $15 Radio Shack crimping tool. A good crimper will set you back about $200, if you're serious about doing a lot of these things. The biggest feature to look for is a ratcheting mechanism that won't release the connector until after you've forced the contacts far enough into the wires to assure a good connection. Some connectors are tougher than others; without the ratchet, you can't be sure that they're consistently assembled.

I like Belden cable for anything. I used to work in professional video, doing a lot of technical work for TV stations and production companies. Belden makes a Broadcast-quality "Belden Blue" video cable; tough as nails and consistent as well. That was the first thing that sold me on Belden cable, and it's all I spec on a job.

As for connectors, check out this PDF file:

http://www.stewartconnector.com/cat6bro.pdf

They have a great little clip assembly that will hold the wires together before you actually push them into the back of the RJ-45. This is not just my favorite kind of connector to crimp on, but it's also got an anti-snag boot! Excellent for cabling newbies and pros alike, since they're so easy to install.

I am a newbie to running cable, if there is such a thing--I was asked to wire half our building (small building) sometime last year and had no prior know-how--so any help or tips I can get on the best cable/connectors to get the best throughput would be great.

Well, at 100 mbps, Cat 5E or Cat 6 will make a small difference. I doubt you'll notice it unless the cables are really long. If you're familiar with airports, you'll know that the terminals are usually fairly long buildings. It would make a big difference there.

The bigger reason is to plan for the future. 5 years from now, you don't want to have to completely re-run all the cables; gigabit ethernet is still exotic enough that it probably won't be mainstream until then, and it will be nice to have built for it.