[Top] [All Lists]

Re: [RFI] grounding ... [was DigiKeyer II] (Dale)

To: "'Mark Hawley'" <hawley.mark@comcast.net>, "rfi@contesting.com" <rfi@contesting.com>
Subject: Re: [RFI] grounding ... [was DigiKeyer II] (Dale)
From: "EDWARDS, EDDIE J" <eedwards@oppd.com>
Date: Mon, 23 Dec 2013 16:25:56 +0000
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
Excellent point Mark!  And thanks to Dale for answering all those questions 
this weekend.

In R56 you are bound to find info that is close enough to what you need to do 
at you home ham shack.  Also, for ham shack specific concepts read the three 
part lightning article from QST in 2002 by Ron Block (relation to Roger Block 
from Polyphasor who wrote the now out-of-print book "Grounds For Lightning And 
EMP Protection"--some of the diagrams are in the QST article).  Search ARRL.org 
site for QST articles: http://www.arrl.org/arrl-periodicals-archive-search key 
word "Lightning".

Main things for hams to focus on for lightning protection: 
(1) ground all cable shields to grounded tower legs every 150 ft or at the top 
& bottom and/or entry into house; 
(2) solid-tinned, buried, outside-perimeter ground buss w/rods every 16 feet 
(doesn't need to surround entire house, but must be long enough wire  to 
connect all cables & utilities grounds; 
(3) surge protectors (Polyphasor or equiv.) on each RF cable entering home and 
AC surge protection for everything inside; and 
(4) internal radio equipment secondary ground buss tied back to single point 
master ground buss at cable entry point.

If you do these four things as close as possible to following R-56 specs, you 
could probably operate your station throughout a thunderstorm; however, since 
equipment damage risks/costs will come out of your own pocket, you may still 
want to disconnect and ground all your valuable stuff anyway unless money is 
not an issue for you.  I disconnect & ground via antenna switches at home, but 
at work it has to operate 24/7 so we always have some tolerable risk to our 30 
radio sites.  Been almost 20 years since we upgraded to R-56 and only lightning 
failures happen when a tech forgets to ground a new cable somewhere.

Oh, and special rules: 
(1) Never use braided ground cables outdoors or in damp environments (or at all 
if possible).  Tinned copper or flat straps only if possible.
(2) Avoid copper to steel connections especially grounded steel anchors to 
avoid galvanic corrosion problems.  Use brass in between.

And for you guys who just cannot get enough from R56, google search for Army 
Tech Manual TM 5-690 or IEEE Standard 1100.    Happy Holidays and Merry 
Christmas to all!

73, de ed K0iL

-----Original Message-----
From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of Mark Hawley

Although this Motorola document is written for commercial installations, the
information is straight-forward enough to apply to more modest amateur
installations and may be of some help. It covers many grounding
configurations and has lots of diagrams.



RFI mailing list

This e-mail contains Omaha Public Power District's confidential and proprietary 
information and is for use only by the intended recipient.  Unless explicitly 
stated otherwise, this e-mail is not a contract offer, amendment, or 
acceptance.  If you are not the intended recipient you are notified that 
disclosing, copying, distributing or taking any action in reliance on the 
contents of this information is strictly prohibited.
RFI mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [RFI] grounding ... [was DigiKeyer II] (Dale), EDWARDS, EDDIE J <=