[Top] [All Lists]

Re: [RFI] Long distance grounding

To: rfi@contesting.com
Subject: Re: [RFI] Long distance grounding
From: Martin AA6E <aa6e@ewing.homedns.org>
Date: Mon, 11 Jun 2007 21:17:13 -0400
List-post: <mailto:rfi@contesting.com>

One point of view is that there is no need for an "RF ground" if your 
antennas and feeds are properly balanced.  (No RF on the coax, etc.) On 
the other hand, if you are running a long wire antenna out of your 
shack, your rig and ground line are definitely part of the antenna!

Few of us have real RF grounds.  According to a rule of thumb, a ground 
needs to be shorter than about 1/10 wavelength to avoid phase shift 
problems.  That would be 3 feet max. for 10 meters.

AC safety grounds matter, and lightning/surge grounds matter, but not so 
much "RF" grounds.  20 ft should be no problem for AC safety.  For 
lightning protection you want a single-point ground system that is 
bonded to your house ground and any other available grounding rods, etc. 
by a low-impedance path, "as short as possible".  20 ft may be OK if all 
your shack power, antenna, and other leads (data network, telco) are 
surge protected locally against the SPG. (An example: 
http://blog.aa6e.net/2005/03/in-shack-ground-system.html )

73 Martin AA6E

Dave Cook wrote:
> Hi folks, I'm revamping my shack and and wondering how to ground a set of
> radios that is on the opposite wall from where my RF ground is located. The
> primary location is occupied by one set of radios and the only other place
> for the other set is on the opposite wall which is 14 feet across the room.
> Given this distance, routing the ground wire would probably result in at
> least 20 feet before it reaches the main ground bus. This is located at an
> interior wall, so there's no other way to run a shorter ground outside of
> the house except straight down through an inaccessible portion of the
> crawlspace.
> I'm wondering if the long ground line would be feasible, or would it simply
> become part of the antenna system? If the latter, what other alternatives
> might I have?
> Thanks and 73, Dave, WA0TTN
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi

RFI mailing list

<Prev in Thread] Current Thread [Next in Thread>