[1000mp] Braid or strap for ground wire...big question.

Thu, 2 May 2002 06:20:23 -0400

It's single point vs. Multi point grounding system.   No grounding
system in the shack is  good unless the outside/perimeter ground system
is done correctly.  Search for FAA (Federal Aviation Administration)
Grounding, Lightning Protection, Procedures, Standards, etc. on the net.

I am sorry that I can not give you better directions to the site for now
(off to work), but the agency has some Really good documentation in
implementing a good grounding system.  I have the documents some where
in the house - but the jest of it is that no matter what you do inside,
will not work if the outside is not done correctly.

I used to work as a systems engineering contractor to one of the FAA's
main En Route Air Traffic Control Center.  Two July's ago they took a
direct lightning hit to one of the towers in the inner circle of
protection.  Their system kept on cranking away without missing a beat.
Except, the temporary building that I was in; the lightening hit
resulting in frying all of the UPS's, LAN cards, and power distribution
inside the building.  That building was not in the inner circle of
protection nor was it properly grounded.  Several months later they
extended the inner circle of protection to include the building.

Their outside ground grid and every thing associated with it is tied to
ONE SINGLE Ground... Inside the building they use Multi Point
grounds........  You can run every ground inside your house directly to
the single outside ground, but this system is typically not good for
reducing noise and interplay among electronic equipment.  Multi point
grounding is typically used for electronic systems.

I run a 3 foot 1 inch copper pipe in back of my desk.  All of my
equipment is tied to this pipe with the shortest piece of of braid (you
can use strapping).  Wide is good; Wider is better.  The pipe is tied
directly to my house's ground system (this is not the electrical
neutral).

But remember if the outside ground system is not done properly, it
doesn't matter.  Everything outside, house, power distribution, tower,
antenna, etc.  Need to be tied to a single ground system or be
referenced to it (other words, if you measure the impedance between the
tower and your house's ground system it should be basically zero.  The
FAA standards/proceedures tell you how to do this.

The documents are usually Adobe and down loadable.

Ron..... NU1U

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Charles Harpole
Sent: May 01, 2002 23:09
To: [email protected]; [email protected]
Subject: [1000mp] Braid or strap for ground wire...big question.

Some say braid is a good wire to use to run from rig to ground rod(s) 
because it offers many lengths of individual wires and maybe avoid
ground 
loops and ground wire resonance(s);  some say solid copper strap is good
for 
same use because it is only one electrical length and can be cut for 
non-ham-band-resonance (maybe).

Which is best????

And, to further muddy the water...  some say (1) run ground wire or
strap 
from one rig to another with shortest runs and then just one wire from
that 
to ground rod(s)
others say (2) run a ground wire or strap from each piece of gear to
ground 
rod(s).  (3) others say use several different lengths of grounding wire
to 
avoid resonances.

P.S. :  Is the coax braid in the coax that connects the rig to the
linear 
also a ground conduction (just because it also has RF on it makes a 
difference???) ?????

So there!  de K4VUD

_________________________________________________________________
Chat with friends online, try MSN Messenger: http://messenger.msn.com

_______________________________________________
List Moderator: Richard Lubash N1VXW
1000mp mailing list
[email protected]
To Change Options or Unsubscribe:
http://mailman.qth.net/mailman/listinfo/1000mp