THAT is one impressive and information filled manual. Gives me a lot to
think about, particularly with regard to bonding the grounds at the AC
entrance and the telephone entry box, both having separate grounds of
questionable integrity and separated from each other by lots of feet of
concrete driveway!!! Tower is also NOT a short distance away from the house
and on the opposite side of course of the existing AC and telephone grounds.
Tnx for bringing the manual to our attention. I suspect I'm not the only one
who was unaware of it.
Some good 'stuff' to absorb.
Don W7WLL
-----Original Message-----
From: Matthew King - KK4CPS
Sent: Saturday, September 06, 2014 11:36 AM
To: Bill Winkis (KC4PE)
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] G-2800DXA lightning damage
With the amount of metal a lot of guys have in the air (Bill, KC4PE has no
small amount - I'm literally 10 miles up the road and have ogled his
antenna farm several times. Hi, Bill!) and the number of feedlines &
control lines coming into the shack, disconnecting is simply not a viable
option.
Proper grounding is CRITICAL to a shack, not just "...stick a rod in the
ground..." as that ain't gonna cut it. That's a small start and nothing
more. The ground SYSTEM must be BONDED to the MAINS ground as well or
you're asking current from a spike of some sort to flow through your
equipment as part of its path of least resistance to ground.
One certainly should protect the power side of the equation as well.
Everything in the shack should go through a UPS or through quality surge
protection devices. Bill already linked to the excellent PolyPhaser white
papers.
I think we can all agree that Tom, W8JI seems to have this ham radio stuff
largely figured out. It's my understanding that he doesn't have equipment
trouble despite visually confirmed lightning strikes on his LARGE antenna
farm. That's because he took great pains with his installation. His
grounding page is another excellent resource, another that Bill has linked.
When I worked for a Motorola Service Center, we had to adhere to the
Motorola R56 standard for all major systems. Google it. THAT is the
station grounding/protection bible. If you get down to it, everything
metal in the shack should be bonded to ground. That ground should consist
of MANY rods driven in a ring around the shack and linked to the ring/rods
driven around the tower.
I can't quite pull off a ring, because of the location of my shack, but
I'll put every effort into getting as close to it as I can when I get my
tower installed. With all the proper protections in place, I don't
anticipate lightning issues.
Station lightning protection is a multi-pronged approach. I don't purport
to know all there is about it, but I do know that the links above and the
R56 standard are awfully good places to start.
Insurance ain't a bad idea, either. *:-)*
Matt
KK4CPS
On Sat, Sep 6, 2014 at 7:49 AM, Bill Winkis (KC4PE) <kc4pe@mindspring.com>
wrote:
Proper Grounding....????
Can we agree that a static crash/lightning/begins with a positive charge
in
Mother Earth, whether it be your Air Conditioner compressor/your vertical
antenna/your tower/and on......so whatever is being charged must have a
proper ground with a proper bleed off, or the charge will continue until a
atmospherically provided path couples and then BOOM, lightning/damage to
whatever.
SO ..if one provides a proper text book ground he will have no problem to
bleed off this charging he will have zero problem
Read On...!!!!
https://www.google.com/?gws_rd=ssl#q=lighning+glen+zook
http://www.w8ji.com/station_ground.htm
Take the time to read the below...especially PolyPhasers WHITE Papers
http://www.smithspower.com/brands/polyphaser/services/media-library/white-pa
pers?page=2
-KC4PE
http://www.kc4pe.com/amateurshack.htm
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
Kenneth Goodwin
Sent: Friday, September 05, 2014 3:10 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] G-2800DXA lightning damage
Agree, disconnecting everything is the only reasonable means of
protection.
If your radio equipment is hooked to a power outlet and/or a computer,
those
connections will have to be disconnected also unless one feels confident
enough to have the power/network/Internet/telephone connections protected.
Near field lightning hits which are the highest probability of occurring
for
most nominal station configurations, will result in two common scenarios.
They obviously induce large amounts of energy into antenna systems and
such
things as one's security system if it has long wired connection paths,
e.g.
window sensors on one loop. Near field hits will also bring the energy
right up the ground connections as the potential level of one's land is
raised with the hit (the reason for single point grounds). Don't rely on
your Internet provider even if they have what looks like a protection
device
in the cable. They just normally ground the shield connection if cable
Internet/TV/VOIP telephone is used. Same applies to one's telephone if
that
is another wired connection. Since disconnecting every secondary
connection
is difficult, having protection for all of those other 'connections' is
probably the next best step. Disconnecting one's antennas/control lines is
still desirable regardless since the probability of one's antennas
conducting energy is > 0. One also needs to remember the impact of
today's
house insurance deductibles. Last thing I want to do with my house
insurance company is file a claim. It's why I use the ARRL Insurance
program for my most expensive radio equipment. For my secondary
connections, I use multiple UPS's for power, have a gas discharge device
in
my Comcast cable as it enters the house in addition to protection at the
network box interface. My TV/Internet cable runs above ground except for
the connection from the pole to the house where it runs underground as is
normally implemented by most cable companies. In the newer neighborhoods,
underground utilities are worth every indirect penny it costs. I use
surge
protection for the AC power at the breaker box and telephone line
protection
(MOVs) at the line entrance to the house. I tried protecting the AC power
at the pole but the electric company didn't like that even though I own
the
underground wire from the breaker box to the pole. They rightfully demand
control for everything from the power meter back. I know I can't fool
Mother Nature even with my single point ground system since I have so many
back doors. I realize the commercial people are able to do it, but they
start out with a fresh sheet of paper and can easily design adequate
lightning protection from the very beginning with a no exception single
point ground system. Ken K5RG
------------------------------
Message: 5
Date: Fri, 05 Sep 2014 07:40:21 -0600
From: Steve London <n2icarrl@gmail.com>
To: towertalk@contesting.com
Subject: [TowerTalk] G-2800DXA lightning damage
>I live in an area with high monsoon thunderstorm activity. I doubt that
>any
of the protection devices would > survive. I disconnect everything where
it
enters my radio shack.
>Spencer W1GAK
I live near Spencer, and 100% concur with his recommendation. Put a Jones
plug at the control box and keep it disconnected during the thunderstorm
season unless you are actually on-the-air. If you are using a computer
connection to the control box, disconnect that also.
73,
Steve, N2IC
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