Grounding does not prevent strikes. What a proper grounding system does do
is allow for any lightning strike that does happen is condected safely into
the surrounding soil and not arc through any equipment/structure trying to
find a lower resistance path to earth.
Wilson Lui
ATI Tectoniks
wilsonlui@atitec.com
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of David Robbins K1TTT
Sent: Tuesday, July 06, 2004 5:53 AM
To: 'Tom Rauch'; reflector -tower
Subject: RE: [TowerTalk] Lighting
Its definitely a myth. Grounding does not prevent strikes, though it
may stop you from getting damage from strikes so you don't know you ever
had them. Also the statistics of the geographic distribution of strokes
is such that it takes 5-10 years of collecting damage data to determine
if a protective measure has done any real good. Comparing one year to
the next or even worse month to month is totally worthless as the
geographic distribution of strokes varies radically over short
periods... so someone who says they took several hits last year, did
something, and then got no hits this year is likely just seeing the
normal year to year variation of stroke locations.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of Tom Rauch
> Sent: Tuesday, July 06, 2004 11:47
> To: Alan AB2OS; towertalk reflector
> Subject: [TowerTalk] Lighting
>
> > Incorrect. The building I work at (TV station) has
> equipment connected
> > just fine, thanks. The transmitter is directly connected
> to the antenna, no
> > 'lightning arrestor' of any kind in between. How the hell
> does it
> > survive this?
>
> Same at my QTH. My tall tower gets hit several times a year
> and I almost never have damage. I don't have a single
> lighting suppressor in any feedline, and all my feedlines
> and radios stay connected even in storms! If I do lose a
> component, it is generally something related to the miles
> and miles of receiving antennas I have. Last week I lost a
> tiny DPDT relay 1/2 mile from the house when the coil opened
> up, and a 2N3904 transistor that hangs off the control lines
> to that relay coil.
>
> When I take significant damage, it is generally something a
> lightning suppressor would never fix. I've had control line
> and coaxial cable blow in two from lightning currents in
> hard hits, but these are cables that run for hundreds of
> feet and are grounded to different grounds at both ends.
>
> By the way, something has been bugging me a bit. A local Ham
> seemed to imply he put in ground rods and stopped getting
> hit. Is that a popular myth (that grounding prevents hits),
> or did I misunderstand what he was saying?
>
>
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers",
"Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041
with
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|