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Bought patches or make them CAT5E

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wybnormal

Technical User
Apr 8, 2000
2,170
US
I had a bit of fun yesterday working with my upgraded Pentascanner350. I tried testing various cabling I had here..

Using the CAT5E350 mode which gives a "band" rating.. rather then a PASS or FAIL, I found some interesting results.

CAT5 Cable - Failed as it should.. cabling should not pass the cat5E test..

CAT5E cabling- sometimes passed.. sometimes not. I had terminated this cabling myself and remembered that my connectors are CAT5 only.

What would happen on the cable is 1 pair would be out of spec on the NEXT test.. normally the middle pair where the end pairs would test fine. Almost like the connector "bowed" slightly when crimped.

Does anyone know the difference between the cat5 and cat5E connectors? DO you even terminate patch cords at Cat5E or just buy them premade?

Thanks

MikeS


PS-- the band measurement on the Pentascanner is pretty cool Find me at
"The trouble with giving up civil rights is that you never get them back"
 
Buy them, purchase them, and use only pre-made cables.

I also only buy cables with molded boots. Generally roll-your-owns are made with left over solid core structural wiring with a Teflon plenum rated jacket, while commercial cables are stranded with a nice, flexible PVC jacket. The combination of extra flexibility and the boot makes them MUCH more reliable if they're used more than once (in my experience anyway.) The boots also cover the little tab that not only holds the connector in the jack but is specifically designed to hook on everything in sight when you try and pull a patch out of a bundle.

Also, pre-mades are generally tested at the factory. Even funky, special lengths will have a slip on boot instead of molded, but they're still pre-tested.

The labor to make and test your own alone more than makes up the difference (Your cost to the company is not just your salary but also benefits AND the lost time that could have been spent on something else.) Add in the better durability and reliability and I honestly can't recomend making a cable except in an emergency.
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....
 
Jeff-

sometimes buying the cables is a luxury that I dont have at the moment.. you know. the client decides at the last possible second to move something or add something and I need to get a cable in the next 10 minutes. The Cat5E is not a real problem so far.. but it's gonna be in the near future.

I am testing myself just to see how close can I reasonably get to the spec for these short notice "emergency" hook ups.

An idle mind is a terrible thing to leave loose ;-)

MikeS Find me at
"The trouble with giving up civil rights is that you never get them back"
 
Can you stock a few and charge them back? From my (admittedly limited) understanding of CAT5 vs CAT5e I have gathered that 5e is still only guaranteed to 100Mz. The only difference in the specs I know of is that it specifies the twists and grounding of the unused pairs whereas CAT5 didn't. The 350 Mhz rating is the vendors trying to future proof against the proposed CAT6 standard. (This is what I've understood from my reading - I could be wrong)

In any case, Trying to get reliable 350Mhz performance out of hand crimped cables is probably going to be a real pain... :-(
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....
 
Jeff, we've had this discussion before and I'll still use up my short boxes to make patch cords during slow times (which is better making patch cords on company time or cruising the internet?) and can consistently test my cables to higher standards than my control group of factory made.

You are correct about the solid core cable decreasing flexibility of the patch but the Teflon plenum rated is a mis-statement. You should only use plenum when you have a plenum rated ceiling otherwise you are wasting your client's money. I find most non-plenum CAT5e jacket as flexible as any patch on the market.

This is not to say that I don't predominantly use factory made patch cords, shoot I can pick up the standard lengths for under a dollar a cord, but I can't justify throwing away every box of cable that doesn't match my run perfectly and isn't enough to start a new one.
 
MAXG-

Can you make your patch cords that pass the CAT5E testing at 350Mhz using the Pentascanner? If so, are you using CAT5E connectors and can you *see* what the difference is? perhaps the dialectric strength of the plastic?> which I thought was for voltage.. not signals.. or perhaps they have "doped" the plastic with some type of ferite for noise reduction?

Thanks!

MikeS
Find me at
"The trouble with giving up civil rights is that you never get them back"
 
I get an error when I try and run the 350 test and am searching to find out why (guessing option wasn't purchased) but in looking at my ratings as compared to the proposed standards I wouldn't have any problems pushing 350mhz over the patch cables I make. I don't use CAT5e mod plugs, just CAT5 I think a lot has to do with the crimp tool you use, I've seen some cables made with cheap crimp tools that I wouldn't put into a 10meg network.
 
Maxg,
My statement is based on my experience with office environments and mixed manufacturing and office environments, where over 90% of the runs I've dealt with have gone through a plenum at some point. I would certainly agree three are environments where that would be different and it would make sense to stock both types of cable.

Are you putting boots on your cables? The lost time due to cables catching on things has to be factored into their lifecycle cost. Time has to be factored. What's more cost effective - lost time making cables or surfing the Internet, researching new technologies that canhelp your business? I figure cables cost $1.00 per minute plus materials to make. Different companies handle their labor accounting and priorities differently and will use different figures.

If you are going to make them I would very much agree with using GOOD tools.
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....
 
This is why I was asking about the connectors. I have been crimping with a high quality AMP crimp tool but "cheapo" connectors (Radio Shack) long story how come ;-)

I need to get some samples of various vendors and run some tests..

MikeS Find me at
"The trouble with giving up civil rights is that you never get them back"
 
Jeff, Of all the places I've run cable I've only hit one plenum rated ceiling, must be different standards and/or regulations in our respective areas.

Now, I agree whole heartedly that time must be factored into this discussion and I have yet to meet a person who doesn't waste at least a half hour in a day. I can make and test almost ten patch cables in a half hour, are my salary and benefits better spent picking the grime from above the drop ceiling out of my fingernails or making up a few patch cables. To answer the question, I don't use a boot and if I snap off the tab on the connector I decide on a case by case whether I chuck the cable or cut off the end and throw a new one on next time I'm thinking about seeing how many times I can spin my chair on one push. And I still go back to the fact that I'm throwing away a couple bucks worth of cable every time I get under 50'. Add that to the number of boxes I go through in a year and you're talking about a serious chunk of change. Even more if I'm tossing plenum.

MikeS, I use either AMP or Dynaflex (for a cheaper, yet still reliable option) plugs.
 
Impedance. The subtle differences in conductor or trace layout, even the width of the trace, the length, etc., are not so subtle at higher frequencies. Controlling the impedance, inductance, capacitance, etc., is a fine art that is not apparent when looking at the physical connector.

But the increases in speed on your PC are due to the increased control of impedances allowed by increasingly refined manufacturing techniques.
 
>What would happen on the cable is 1 pair
>would be out of spec on the NEXT test.

Was this with plenum cable? If so see this white paper on Microtest's site concerning skew.

>I have been crimping with a
>high quality AMP crimp tool.

Last I checked AMP crimp tools were only compatible with AMP connectors. used to have a tektip on the differences. I went through half a box of AMP RJ45's trying to get a good connection with a standard crimp tool.
Since then I have steered clear of AMP RJ stuff.

>Are you putting boots on your cables?

I don't need them. Check out Panduit's snagless RJ45's Very nice...

I don't tend to use premade cables, too big a PITA. The premades are either too long or too short or I don't have enough. It takes me about 50 seconds to put on a RJ45 plug so assembled and tested patch cords are about 3 minutes each AND they are the correct length and color. I usually have a bundle of PVC soild wire trims from wire run jobs that are different colors that I use to make patch cables. Colors are great! As far as cost I figure it is a break even to slightly cheaper proposition for me to make my own. Don't forget the costs in ordering, receiving, inventoring, transporting to the job and billing for premade cables!

As far as testing I use a PentaScanner+. Since making your own patch cables is considered heresy by many my patch cables have been tested with OmniScanners (by folks who wanted to flunk them) and pass with flying colors up to the rating on the wire.
 
>What would happen on the cable is 1 pair
>would be out of spec on the NEXT test.

Was this with plenum cable? If so see this white paper on Microtest's site concerning skew.

No- it was with both CAT5E stranded and CAT5E solid. The cables pass great at CAT5 but on fails on CAT5E. The outer pairs crimp fine and pass NEXT at CAT5E but the inner pairs fail( by the barest margins) which leads me to think it has something to do with the connectors themselves.

>I have been crimping with a
>high quality AMP crimp tool.

Last I checked AMP crimp tools were only compatible with AMP connectors. used to have a tektip on the differences. I went through half a box of AMP RJ45's trying to get a good connection with a standard crimp tool.
Since then I have steered clear of AMP RJ stuff.

I recall something like this from awhile back but I thought it was their connector design not so much the crimper. This crimper has made more then a few CAT5 cables without issue.. it's only with CAT5E that some problems are starting to pop up.
Find me at
"The trouble with giving up civil rights is that you never get them back"
 
... I would be interested to know the cable mfg and type. I've been partial to Belden because of their excellect quality and reputation, which I use as a selling point to clients. There are, I believe, some differences between cables as there are between Chevy's and Buicks.

Also, yes, the AMP tool is designed to work only with their connectors. While the specs for 8-pin jacks (precisely speaking they are not Registered Jack [RJ-xx] types) are available online via the FCC Part 68 docs, there is room for enough physical variation that some dies will not work with some connectors.

This is not unusual. BNC connectors are the same way. While there are various excellent connectors from Canare, Trompeter, AMP, and others, you may find that for best fit, they should be used with their cables or with cable manufacturers specifically referenced in their cross-reference tables, as there are tiny differences in diameter.

And, yes, also--the Panduit termination hardware is generally excellent.

This is an area where the engineer who writes specs for a job begins to pay his salery, as a vendor can comply with loose specs and still have problems on the job. And it won't always be the vendor's responsibility to fix it.

Yours,
Mike
 
The solid is the following:

Quabbin Datamax Enhanced Patch Cord/Jumper PN 5404
ETL Verif TIA/EIA 568A CAT5

MikeS Find me at
"The trouble with giving up civil rights is that you never get them back"
 
The reason AMP connectors must be matched to AMP crimpers is the position of the secondary strain relief. Cheaper crimpers will only use the primary strain relief so there will be no interference. AMP, for whatever reason, chose to position their secondary strain relief in a different postion than everyone else. The MilesTek FAQ has illustrations of this.
Jeff
I haven't lost my mind - I know it's backed up on tape somewhere ....
 
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