[R-390] Ham Shack Grounding Help!!!!

Jim Brannigan [email protected]
Fri, 21 Jun 2002 12:34:50 -0400


Dan,
In the same vein.......
The Shack ground is driven ground rods.......it serves for AC/DC and RF.
The pipe is at the bottom-back of the table for convenience and cosmetic
reasons.

The workbench is another story.......there I use a single cable from chassis
to ground.
A pipe ground would be handy for the test equipment.
Additionally, I use rubber mats in the shop and the Shack is
carpeted....other common sense rules apply

Jim
----- Original Message -----
From: "Dan Merz" <[email protected]>
To: "Jim Brannigan" <[email protected]>; "R-390 List"
<[email protected]>
Sent: Friday, June 21, 2002 12:06
Subject: Re: [R-390] Ham Shack Grounding Help!!!!


> Jim,  I bet this is a dead horse ready to ride.... the thought of having a
> ground pipe under my desk or workbench conjures up the image of working on
a
> radio while standing in the bathtub filled with saltwater.. I offer this
as a
> consideration,  not as a criticism.  I'd prefer to have a good ground
where I
> can see it and not necessarily become intimate with it.    I'm sure your
system
> serves you well and I admire your effort in implementing it.  If I had a
lot of
> equipment in fixed locations,  it might serve me.  My main concern when
working
> on anything electrical is to keep all parts of my body at a single
potential and
> to avoid the accident of touching different parts of me to different
> potentials.  Half of the concern is the location of ground relative to my
body.
> The other half is keeping out of touch with the "high" potential areas.
On a
> lot of projects on old radios,  I use a fused isolation transformer so I
know
> earth ground is not part of the equation as far as the electrical mess
that is
> setting in front of me.  Maybe I need to rethink whether your system could
help
> me - one problem I have is getting a reliable "water pipe" type ground
> connection into my radio area. Dan
>
> Jim Brannigan wrote:
>
> > One should never rely on the outlet ground, there are just too many
> > variables.......
> > My station ground is based on the Handbook model.
> > A 1/2 inch copper pipe is mounted under the desk and braid is run from
the
> > pipe to EACH piece of equipment.  A heavy wire is run from the copper
pipe
> > to the earth ground system.
> > On installation, the ground braid is connected to the chassis before the
> > radio is plugged in.
> >
> > As an additional safety feature, the Shack outlets are connected to a
DPDT
> > wall switch.  In the off position, all radios are electrically
dead......
> >
> > Jim
> >
> > ----- Original Message -----
> > From: "Dan Merz" <[email protected]>
> > To: "Roy Morgan" <[email protected]>; "R-390 List"
<[email protected]>
> > Sent: Friday, June 21, 2002 01:34
> > Subject: Re: [R-390] Ham Shack Grounding Help!!!!
> >
> > > Roy/Kim,  I can agree with the 60 v normal when there's no grounded
> > outlet - I
> > > have pretty modern wiring in my home but one day not too long ago
> > discovered  60
> > > volts chassis to ground even though it should have been zero.  I
> > discovered this
> > > by   rf noise associated with touching a wire from an external ground
rod
> > located
> > > outside the house to the radio chassis,  and then measuring about 60
volts
> > ac
> > > between the chassis and the ground wire.    It took me awhile to
discover
> > that on
> > > the leg of my wiring where I have my radios there was no ground coming
to
> > the 3
> > > prong outlet or to any of the several other outlets on the same
circuit -
> > easily
> > > detected by plugging in one of the circuit checker gadgets - but not
so
> > easy to
> > > remedy.  Fortunately I was able to get into the junction box where the
> > problem
> > > originated (conveniently left somewhat visible by the previous owner)
and
> > found a
> > > ground wire that was not firmly connected to the bundle of ground
wires
> > connected
> > > there.  Too many connectors in an undersized wire nut and with no room
to
> > tighten
> > > it sufficiently !!  I fixed that by better type of connection and the
60
> > volts
> > > went away.   I feel safer now.  I guess if  one of those caps( the one
on
> > the hot
> > > side)   that put the 60 v on the chassis happens to short,  I'll now
be
> > saved by
> > > my circuit breaker or radio fuse rather than taking the potentially
lethal
> > > current myself if I happen to be grounded.       Dan.
> > >
> > > Roy Morgan wrote:
> > >
> > > > At 11:21 PM 6/20/2002 -0400, you wrote:
> > > > >I have received lots of good info that I can use to help eliminate
my
> > noise
> > > > >problems.  I was out all day today so did not get to follow up on
any
> > of
> > > > >this.  Yesterday however I did do one check and it did not look
good.
> > There
> > > > >is 60 v. from the chassis of my radio to the cold water pipe.
> > > >
> > > > Standard condition.
> > > > Caused by NORMAL operation of the line filter capacitors.
> > > > GROUND your radio to the cold water pipe, PLEASE.
> > > > Do not use any ground fault interruptor outlets.
> > > >
> > > > >  Not good at
> > > > >all.  I am going to get an electrician in here as soon as possible
to
> > see
> > > > >what we are going to have to do to fix that.
> > > >
> > > > That is cused by the RADIO line filter. NOT by the electrical system
in
> > > > your house, except that you have ungrounded outlets.
> > > >
> > > > Roy
> > > >
> > > > Roy Morgan
> > > > K1LKY since 1959
> > > > 7130 Panorama Drive, Derwood MD 20855
> > > > 301-330-8828 home .... 301-975-3254 work
> > > > [email protected]
> > > >
> > > > _______________________________________________
> > > > R-390 mailing list
> > > > [email protected]
> > > > http://mailman.qth.net/mailman/listinfo/r-390
> > >
> > > _______________________________________________
> > > R-390 mailing list
> > > [email protected]
> > > http://mailman.qth.net/mailman/listinfo/r-390
> >
> > _______________________________________________
> > R-390 mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/r-390
>
> _______________________________________________
> R-390 mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/r-390