RE: Cat5 or Cat5e for structured cabling (KAT 5 Issues ?)

["Keith Doxey" <lists.diyha@xxxxxxx>]

The twist rate is slightly different between pairs so that the pattern of wires resting against each other is more random. This reduces crosstalk, well to be more precise it doesnt reduce it but ensures that crosstalk is picked up equally >from

 

This results in what is known as "Unitelligable Crosstalk"

 

On telephone lines that run great distances from the exchange there is a sort of "mush" in the background which is the crosstalk from hundreds of other lines but it just blends into the background.

 

By comparison, if someone makes a mistake jointing cables and runs on split pairs

eg    Line 1 on BLUE/WhiteOrange

        Line 2 on ORANGE/WhiteBlue

then the effect is dramatic. All forms of DC testing will prove that each line is perfect, no shorts or earths on the line etc. However because the two pairs are closely twisted together for long distances they effectively becoma a transformer connecting the two cirsuits together. Someone on line 1 would hear someone on line 2 as clearly as if they had both picked up phones on the same line.

 

Whilst the total wire length of the most twisted pair may be slightly longer than the least twisted pair I would not expect any problems. The cable would not be made if that was the case. For ethernet you are using one pair in each direction.

 

KAT5 works equally well on CAT5 and CAT5e and also over ordinary telephone cable but I would not recommend you installing anything less than CAT5.

 

Also bear in mind that any cable runs in a domestic environment will almost certainly be a lot shorter than in a commercial installation.

 

Keith

www.diyha.co.uk
www.kat5.tv

-----Original Message-----
From: Alancc [mailto:alan.cc@xxxxxxx]
Sent: 07 April 2002 20:08
To: ukha_d@xxxxxxxSubject: Re: [ukha_d] Cat5 or Cat5e for structured cabling (KAT 5 Issues ?)

Got different rates of twist on my cables, I thought this was to reduce
crosstalk between pairs

Alancc
----- Original Message -----
From: Ian Lowe <ian@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Sunday, April 07, 2002 6:01 PM
Subject: RE: [ukha_d] Cat5 or Cat5e for structured cabling (KAT 5 Issues ?)


> Thats not as I understand it...
>
> I believe CAT-5e has a different rate of twist to CAT-5 (28 twists per
foot,
> as opposed to 22)
> hence giving better noise rejection, but certainly haven't heard about
> different rates of twist between pairs!!
>
> Ian.
>
> -----Original Message-----
> From: Nigel Giddings [mailto:nigel.giddings@xxxxxxx]
> Sent: 07 April 2002 17:40
> To: ukha_d@xxxxxxx> Subject: RE: [ukha_d] Cat5 or Cat5e for structured cabling (KAT 5 Issues
> ?)
>
>
> Hi,
>
> I have been told that the difference between Cat 5 and CAT 5e is that some
> of the cores in CAT 5e have a different rate of twist...
>
> If this is so, and this also goes on from what I have been told, then the
> delivery of signals down each pair can differ in time causing problems
with
> KVM type solutions over CAT 5e cable.
>
> Any comments ?
>
> Nigel
>

Yahoo! Groups Sponsor

ADVERTISEMENT

For more information: http://www.automatedhome.co.uk
Post message: ukha_d@xxxxxxx
Subscribe:  ukha_d-subscribe@xxxxxxx
Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
List owner:  ukha_d-owner@xxxxxxx

Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.