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Re: [TowerTalk] What is a single point ground (again)

To: <>
Subject: Re: [TowerTalk] What is a single point ground (again)
From: "Gary Schafer" <>
Date: Thu, 5 Aug 2010 22:14:03 -0500
List-post: <">>
Hi Pete,

Yes you have it right. It of course is not the ideal setup but sometimes we
can not do any better. Polyphaser makes such a box. I can't remember the
designation but it is basically an extension cord with an outlet box on one
end. It has power protection devices in it and it is designed to mount on
the SPG panel. As I remember it has gas tubes in it. I assume that you have
all other lines bonded to the SPG panel.

Being on the second floor has its problem with getting the SPG panel
grounded to the ground  system because of the distance to earth. You will
have a rather high impedance in the ground lead from the panel because of
its length.

It may be better to place the SPG panel at ground level and then run the
lines up to the second floor after they enter the house. But then you have
the problem of the possibility of induced currents, from nearby strikes,
into the portion of the lines between the SPG panel and the equipment. But
you can obtain a much better connection to earth with the panel mounted near
ground level.

Either way you at least have ALL lines, including power, referenced to one
point this way with near zero impedance/resistance between all at that

Gary  K4FMX

> -----Original Message-----
> From: Pete Smith []
> Sent: Thursday, August 05, 2010 6:29 AM
> To:
> Cc:
> Subject: Re: [TowerTalk] What is a single point ground (again)
> Gary, are you saying that I can achieve the SPG objective in my second
> floor shack simply by running a short 3-wire extension cord conductor
> from a wall outlet, through a protective device on the SPG, and then
> powering all the shack equipment (which is already bonded to the SPG)
> from outlets off that line?  Other well-known and respected people, in
> response to the same question, have said that you must bring the power
> from the breaker panel, up a dedicated line to the SPG, and thence to
> the equipment.  Obviously, your solution would be far easier, but is it
> code?
> What sort of protective device is needed at the SPG for this power
> circuit, whichever way it is wired?
> 73, Pete N4ZR
> The World Contest Station Database, updated daily at
> The Reverse Beacon Network at, blog at
> spots at, port 7000
> On 8/4/2010 11:32 PM, Gary Schafer wrote:
> > If the utility power is more than a few feet away from the SPG panel,
> the
> > most practical way to maintain a single point ground system is to  run a
> > power line over to the SPG panel and put a protection device for that
> power
> > line directly on the SPG panel, bonded to the SPG panel, and then power
> the
> > equipment only from that power line, after it has gone thru the SPG
> > protector.
> >


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