My previous post answers a couple of the questions.
To the question of where the lightning protection devices should be located,
at, but not in, the house at the SPG is the best location.
But, if that's not feasible, or you've already implemented lightning
protectors at the tower, if the cables go underground after exiting the
metal SPG box (required) at the tower, then all of the energy is off coax
cable center conductor at that point. If you've implemented a metal SPG box
at the house, then the shields are taken to ground at the house, so any
energy on them is removed at the house SPG box. This is also true for
control, non-coax, cables. This is my case. See my example:
www.erols.com/n3rr click on lightning protection.
To your last question about putting lightning protectors inside the shack:
no, never put them in the shack. Put them outside the house, in a metal
box, per my previous post, and ensure they are part of the SPG. The idea is
that you want to control the lightning and put it where *you* want it to go,
not where *it* wants to go, right? So, don't wait until *it* comes into your
house/shack to tell it where to go (pun intended); tell it where to go
*before* it gets in your house!
----- Original Message -----
From: "Jon Ogden" <firstname.lastname@example.org>
Sent: Thursday, September 19, 2002 11:05 AM
Subject: [Towertalk] More Grounding Questions
> Hi all,
> I've got a couple more grounding questions.
> I downloaded and printed out PolyPhaser's app notes on lightning
> I've done a very brief amount of reading and it's raised a couple more
> questions though.
> It appears that if your single point ground, surge suppressors, etc. is
> the tower (where I was going to put mine), your equipment could be w/in
> magnetic field of the tower created by a strike. It sounds like from the
> brief amount that I have read that if this is the case, you could still
> induce a voltage on the other side of all your protection equipment. That
> would render it useless in effect.
> So where do you really want the surge protectors, etc. What sort of
> should they be in? The article suggests a metal housing to shield them.
> that what really should be used? Is the base of the tower the right
> Do you need them inside the shack as well?
> Jon Ogden
> NA9D (ex: KE9NA)
> Life Member: ARRL, NRA
> Member: AMSAT, DXCC
> "A life lived in fear is a life half lived."
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