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From: djdove@hprnd.rose.hp.com (Dan Dove)
Newsgroups: comp.dcom.lans
Subject: Re: Possible Ground Loop problem
Message-ID: <2230162@hprnd.rose.hp.com>
Date: 18 Jun 91 17:21:23 GMT
References: <0094A40A.0DF70DA0@EA.USL.EDU>
Organization: HP Roseville Networks Division
Lines: 27

In comp.dcom.lans, johnson@EA.USL.EDU writes:

>   Also, why should
>   a coax only be grounded on 1 side of a segment?  Why not put a small
>   resistance at the other end to drain that small amount of current which
>   might be there?

    Lee J.

Lee,

The reason for a single point ground connection IS to prevent ground loops.
A problem with your approach would be insuring adequate isolation of the buried
cable shield. It is not real difficult, but would add to the task at hand.
 
The Ethernet coax is isolated from ground at each node, and thus the single
point connection is required to maintain a safety path for static charge.

In addition, each node does have ~1Megohm of DC resistance to provide a 
charge bleeding capability.

I would recommend that you use a fiber link if the co$t is not absolutely 
out of your budget. FOIRL between two repeaters is a pretty good solution.

Good Luck,

Dan Dove