[1979] in linux-net channel archive
Re: Networking without a hub or a router/repeater
daemon@ATHENA.MIT.EDU (Paul Gortmaker)
Sun Feb 25 19:58:22 1996
From: Paul Gortmaker <gpg109@rsphy1.anu.edu.au>
To: erc@dal1820.computek.net (Ed Carp)
Date: Mon, 26 Feb 1996 09:51:09 +1100 (EST)
Cc: linux-net@vger.rutgers.edu
In-Reply-To: <Pine.3.89.9602251050.A9839-0100000@dal1820.computek.net> from "Ed Carp" at Feb 25, 96 10:12:36 am
From "Ed Carp" at Feb 25, 96 10:12:36 am
> Also, you might want to make sure that RG58 is what you want. The
> impedance of RG58 is 50 ohms (give or take), while I believe that those
> BNC connectors are designed to feed 75 ohms. Try a piece of RG74 or
> Belden 9275.
50 ohm cable *is* what you want. People who have tried to stuff an
ethernet signal down 75 ohm "cable T.V." wiring will vouch for that.
(Mind you I am not sure whether they tried 75 ohm terminators as well. 8)
The IEEE 802.2 spec approves coax that is marked as follows:
802.3 10Base2 (50 ohm, stranded tinned core)
RG-58 a/u (50 ohm, stranded tinned core)
RG-58 c/u (50 ohm, stranded tinned core)
The IEEE 802.2 spec does not approve of 50 ohm solid core cables, such
as RG-58 or RG-58 /u coax.
Belden 8259 is equivalent to RG-58 a/u coax.
Paul.
