Date:         Thu, 6 Jun 2002 21:37:33 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: ground straps
Comments: To: brian Honan <cartruckbus@HOTMAIL.COM>
In-Reply-To:  <F119bkA5JIzpNcedZho00011ab5@hotmail.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 08:46 PM 6/6/2002, brian Honan wrote:
>Hi Volks,
>
>   Is it ok to replace the braded ground straps with a batery like cable ?
>In perticular the one to the left of the engine.

There are two reasons for the braid -- one is flexibility/fatigue
resistance and the other is surface area.  That strap is intended among
other things to act as a radio-frequency ground to assist in reducing both
incoming and outgoing radio interference; and it's a characteristic of RF
that it travels only along the surface of a conductor.  A regular stranded
wire would have to be much larger to present the same surface area, which
would greatly aggravate the fatigue problem (I think, haven't really
thought that through).  In any case, to get the equivalent grounding effect
you need equivalent surface area.

Side note -- there is a type of wire known as "Litz wire" in which each of
the many fine strands is individually insulated, and then the wire is
braided together, not just twisted.  This forces RF to travel along the
surface of each of the individual strands, greatly increasing the effective
surface.  Stuff's a bugger to solder, though, since you have to clean each
strand individually.

Second side note -- a lot of very high-frequency RF wiring is done with
silver-plated tubing instead of wires -- the higher the frequency the
greater the "skin effect."

david
ps -- short answer -- not a good idea.  You can certainly get away with it
in emergency.

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"