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[Towertalk] Re: bulkhead ground system

To: <towertalk@contesting.com>
Subject: [Towertalk] Re: bulkhead ground system
From: n2mg@eham.net (Mike Gilmer)
Date: Wed, 24 Jul 2002 23:31:10 -0700
You quoted my entire post, so I'm not sure with what you are disagreeing.
My conclusion was that a single point ground was good/necessary at or near
the cable entrance point even if disconnecting cables.  I also said it was
effective for the EQUIPMENT to unplug the cables.  Could be wrong, but I
wouldn't think these statements are in dispute...

Also, I never said that a bunch of disconnected cables was effective for
preventing a fire from the effects of a direct/near direct hit. What that's
effective for is protecting against the transients caused by not-so-near,
not-so-far lightning hits.  This is far more common than a direct hit.

If you want 24/7 coverage (clearly NOT typical amateur) or (near)direct-hit
protection, clearly further measures are warranted.  Since most hams have no
Polyphasers, no SPG and leave their cables plugged in, they have ZERO
protection.  Unplugging the cables from the equipment is the first step.
One shouldn't stop there.

73 Mike N2MG

N3RR wrote:

> I must strongly disagree.
>
> By disconnecting cables inside your shack in lieu of (instead of) any
> lightning protection, you are leaving your house open to a fire started by
> the arc-over from lightning in any open circuit cable from the outside
> (SO-259, telephone line, dangling PL-259, etc.)  I think it's just stupid
to
> just disconnect the equipment and not have Polyphasers or other similar
> device on each cable entering the house.
>
> I keep all of my equipment connected all of the time, including IC-781
(with
> Beverage and HF antenna cables connected), IC-4KL, 4 PacketCluster radios,
> 6
> rotor control boxes, PCs, telephone wires, etc).  I have a 24/7 fully
> operational station.
>
> If you've seen my website www.erols.com/n3rr , you know I have substantial
> lightning protection installed.
>
> Bill, N3RR
>
> > ----- Original Message -----
> > From: "Mike Gilmer, N2MG" <n2mg@eham.net>
> > To: <towertalk@contesting.com>
> > Sent: Wednesday, July 24, 2002 8:51 AM
> > Subject: [Towertalk] re: bulkhead ground system
> >
> >
> > > N5OT wrote:
> > > > > I still just disconnect everything when I am not using the
station.
> > >
> > > This is probably the single most effective method for protecting your
> > > amateur equipment.  Even the SPG cannot be counted on entirely
> > > protecting your stuff from nasties.  And one does not need to take a
> > > full hit to receive damage.  Close-by hits generate all kinds of
> > > transients that take out stuff like phones, modems and trasceiver
filter
> > > switching diodes all the time.
> > >
> > > I practice good hygiene and usually have the PL-259s (and all the AC,
> > > phone lines, LAN cables) disconnected at my station.  However, the
> > > antenna/rotator/etc. wires still pass through something (a window or a
> > > wall) and enter the house.  It is at that point one has allowed
> > > "lightning" (or its effects) to enter and somehow at or near that
point
> > > it should be dealt with - enter the SPG.
> > >
> > > Mike N2MG
> > >



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