sheilded Cat-5

[Gene Holmerud]

A little more clarification:  

1) Token ring cable can be twisted-pair or shielded.  The sheilded 
form is two pairs of wires, each pair is wrapped in foil to prevent 
crosstalk to the other pair.  It's actually a current loop scheme, 
hence the realitively heavy conductor (#20 comes to mind).

2)  Cat-5 is unshelded, four pairs of wires twisted.  Each pair has a 
different number of twists per foot, which helps minimize the 
crosstalk problem.  And there are standards as to which connector (RJ-
45) pin number each wire connects to, so that the pairing comes out 
right.  Cat-5 can be used for Ethernet.  Unshielded twisted pair can 
also be used for Token-ring, but this T-R must be supplied a small 
amount of power at hubs since it's current carrying ability is 
ziltch.  Mike mentioned CAT-4 UTP was for T-R and that's a new nerdle 
of wisdom for me.

Gene

From:           	"Mike Sheldon" <msheldon@desertraven.com>
To:             	<plug-discuss@lists.plug.phoenix.az.us>
Subject:        	RE: sheilded Cat-5
Date sent:      	Thu, 29 Jun 2000 21:49:34 -0700
Send reply to:  	plug-discuss@lists.plug.phoenix.az.us

> >>When I say twisted, the cables are definently twisted around each other.
> 
> Ahh, you're talking about stranded wire vs. solid core. Either one can be
> certified CAT-5, but be sure that the connectors are for stranded wire. Most
> are for solid wire, and there is a difference.
> 
> I've still never seen shielded CAT-5 before. I'm not saying it doesn't
> exist, but be sure that the wire actually is CAT-5, and not CAT-3 or CAT-4.
> 
> Michael J. Sheldon
> Internet Applications Developer
> Phone: 480.699.1084
> http://www.desertraven.com/
> PGP Key Available on Request
> -----Original Message-----
> From: plug-discuss-admin@lists.PLUG.phoenix.az.us
> [mailto:plug-discuss-admin@lists.PLUG.phoenix.az.us]On Behalf Of colin rasor
> Sent: Wednesday, June 28, 2000 20:00
> To: plug-discuss@lists.PLUG.phoenix.az.us
> Subject: Re: sheilded Cat-5
> 
> 
> Thanks Mike
>  The wire is going in a machine shop.
>  Mike I might be a little confused, (please correct me if I am wrong.) When
> I say twisted, the cables are definently twisted around each other. The
> copper wire inside is not twisted and is solid, is this Cat4? Also the Wire
> that I have seen that claims to be shielded is coated in a foil type
> substance with a bare wire running on the outside of it. Of course this is
> all incased in you typical blue (or color of choice).
>  The reason we worry about using "shielded" is that that we don't want to be
> losing any data do to RF while it is running through the shop.
>  Conduit would be about the same price to run with labor. As the so called
> shielded wire.
> Thank you again for you input.
> Colin Ansel Rasor
> 
> Mike Sheldon wrote:
> Cat-5 isn't Cat-5 unless it's twisted, the twists are what prevents
> interference between the pairs, as well as from outside sources.
> As far as shielded Cat-5? I've never seen such a thing. There was a shielded
> twisted pair that IBM used for token-ring, but that's Cat-4. Cat-4 is NOT
> rated for 100mbps
> Shielded Pros: Less outside interference in extremely noisy (electrical)
> areas.
> Unshielded Pros: 100mbps, much cheaper, resistant to electrical noise in all
> but the worst environments when properly installed.
> Use Cat-5 unless you're wiring a machine shop. If you're wiring a machine
> shop, run Cat-5 in metal conduit.
> Michael J. Sheldon
> Internet Applications Developer
> Phone: 480.699.1084
> http://www.desertraven.com/
> PGP Key Available on Request
> -----Original Message-----
> From: plug-discuss-admin@lists.PLUG.phoenix.az.us
> [mailto:plug-discuss-admin@lists.PLUG.phoenix.az.us]On Behalf Of colin
> rasor
> Sent: Wednesday, June 28, 2000 17:03
> To: plug-discuss@lists.PLUG.phoenix.az.us
> Subject: sheilded Cat-5
>  Hello everybody,
> I was wondering the best place to buy shielded cat5 non twisted. I am
> looking for around 2000ft.
>  What are the pros to using shielded compared to non shielded?
> Colin Ansel Rasor
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