Fw: DB25 to RJ-45 Connectors
Wayne Jordan (wjordan@pcl.net)
Tue, 10 Dec 1996 11:57:10 -0600
----------
> From: Wayne Jordan <wjordan@pcl.net>
> To: Prof Jake Messinger <jake@ams.com>
> Subject: Re: DB25 to RJ-45 Connectors
> Date: Tuesday, December 10, 1996 10:43 AM
>
> First off I use CAT 5 cable from my ISPPorte's RJ45 jack to my CAT 5 RJ45
> patch panel. I actually use one pair of the four pair in each CAT 5 cable
> for each modem, so basiclly I get 4 connections to my modems with one
> cable. I have never had a problem with this type of connection. In fact I
> trust this a whole lot more than silver satin. We've even used CAT 5 to
> wire terminals to Unix boxes at distances of 400' and never had a
problem.
>
> The basic difference, as I understand it, between say CAT 5 and CAT 3 is
> the number of twist in the cable. The tighter the twist the more
bandwidth
> you can get out of the cable. Also the connectors have more microns of
gold
> on them. This is just my non-technical understanding, maybe someone else
> has a better explaination.
>
> ----------
> > From: Prof Jake Messinger <jake@ams.com>
> > To: Chris Trown <ctrown@ecst.csuchico.edu>
> > Cc: jgt10@livingston.com; djelder@accessus.net;
> portmaster-users@livingston.com
> > Subject: Re: DB25 to RJ-45 Connectors
> > Date: Tuesday, December 10, 1996 10:06 AM
> >
> > On Mon, 9 Dec 1996, Chris Trown wrote:
> >
> > > Hmmm... How can you avoid crosstalk if all the wire in your
> bundles is
> > > straight? Seems to me you need twist.
> >
> > Does anyone know HOW twisted pair works? You cannot just twist whatever
> > you want. It works by tiwsting opposing pairs such that their signals
> > cancel each other out, or pulse in harmony, or whatever you wanna call
> it.
> > One wave goes up while the other goes down. That is how I am to
> understand
> > it in laymans terms.
> >
> > I was told that you must be careful when making ethernet TP cable
because
> > if you twist the wrong pairs, then you have worsened the transient
> > problem. I read this in a 3 com manual and also was told it by a tech
guy
> > at SMC long ago.
> >
> > So as far as I know, I dont think just twisting some of the pairs
> randomly
> > would help. What wires would you twist on a serial connection anyway?
Or
> > does it really matter? Ive run flat satin as far as 100 feet and seems
to
> > work fine. In places where I thought there would be lots of IF, I used
> > shielded NON TWISTED pair. I dont think Ive ever tried to use TP cable
to
> > make a serial cable, so I couldnt tell you whether it caused a problem.
> >
> >
> > > > Chris...
> > >
> >
> >
>
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
> > Jake Messinger 713-772-6690 jake@ams.com
> > Advanced Medical Systems, Inc. 800-324-8594 jake@uh.edu
> > Houston, Texas http://www.ams.com/~jake
> >
>
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
> >
> > (Don't steal my squigglies)
> >