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Mac Grounding

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Eric Swartz - WA6HHQ

Re: Mac Grounding [END of Thread]

Administrator

Let's end the Mac grounding thread for now. Looks like we have covered
all the bases on this one.

73, Eric WA6HHQ
List moderator
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Alan Bloom

Ligntning protection

In reply to this post by Byron Servies

On my workbench right now is a Harris 1 KW commercial RM transmitter
that belongs to KBBF, the local non-profit bi-lingual radio station. It
has a blown CPU board due to a lightning strike, which also destroyed
the power pole feeding the transmitter shed. Even here in Northern
California where lightning storms are rare you do have to pay attention
to proper grounding.

Al N1AL

On Tue, 2011-04-12 at 07:49 -0700, Byron Servies wrote:

> Hi Phil,
>
> I think what people are trying to point out is that the instant the
> need becomes visible, it will be too late. May that time never come,
> and good luck!
>
> On Mon, Apr 11, 2011 at 7:11 PM, Phil Hystad <[hidden email]> wrote:
> > I understand the technical reasons that people suggest for grounding but I do not see the need.
> > I have no problems.
>

Jim Brown-10

Re: Mac Grounding

In reply to this post by Edward R Cole

On 4/12/2011 11:07 AM, Edward R. Cole wrote:
> None of my computer chassis are grounded directly to my radio
> grounds. I made it especially that way to avoid audio ground
> loops.

That's why I abhor the phrase "ground loop" -- it causes people to do
exactly the WRONG thing, just as you have done. AC hum, buzz, and RFI
are CAUSED by not bonding together equipment that is interconnected.
Study the tutorials in the links I posted yesterday to understand why.

And, as W3FPR has observed, this same lack of bonding that causes hum,
buzz, and RFI also can cause severe damage in the case of a lightning
strike or power line spike.

Bottom line -- bonding equipment together, bonding it to your station
ground, and bonding your station ground to all other grounds in your
home, are critical both for lightning safety and for minimizing hum,
buzz, and RFI. Most important -- ERASE THE PHRASE "GROUND LOOP" FROM
YOUR VOCABULARY!

73, Jim Brown K9YC

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Joe Subich, W4TV-4

Re: Mac Grounding

I realize that Eric has ended this thread but I *must* reinforce
Jim's comments.

If your RF ground and utility entrance (power, cable TV, telephone,
satellite TV, emergency generator, etc.) are not *ALL* bonded with
a low impedance conductor you have an extremely dangerous situation.
It is only a matter of *WHEN* not *if* someone is injured or you
suffer significant loss/damage from a lightning induced surge event.

73,

... Joe, W4TV

On 4/12/2011 3:04 PM, Jim Brown wrote:

> On 4/12/2011 11:07 AM, Edward R. Cole wrote:
>> None of my computer chassis are grounded directly to my radio
>> grounds. I made it especially that way to avoid audio ground
>> loops.
>
> That's why I abhor the phrase "ground loop" -- it causes people to do
> exactly the WRONG thing, just as you have done. AC hum, buzz, and RFI
> are CAUSED by not bonding together equipment that is interconnected.
> Study the tutorials in the links I posted yesterday to understand why.
>
> And, as W3FPR has observed, this same lack of bonding that causes hum,
> buzz, and RFI also can cause severe damage in the case of a lightning
> strike or power line spike.
>
> Bottom line -- bonding equipment together, bonding it to your station
> ground, and bonding your station ground to all other grounds in your
> home, are critical both for lightning safety and for minimizing hum,
> buzz, and RFI. Most important -- ERASE THE PHRASE "GROUND LOOP" FROM
> YOUR VOCABULARY!
>
> 73, Jim Brown K9YC
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

daleputnam

Re: Ligntning protection

In reply to this post by Alan Bloom

After spending a career chasing storms, each summer, following them, strike by strike, repairing the damages to commercial communicatins radio systems, and wishing deeply that there were a way to avoid the waste of time and resources in repairing the inevitable lightning damage.... Motorola gathered together, and published their R56 grounding standard, Polyphaser, a company that has made many an engineering carreer paid for, by placing arrestors in line... published a number of white papers on the subject...
I then had the oppurtunity to embrace this information, and put it to a test. The very same tower site, that had previously taken one strike and damaged three stations, one beyond repair, was put to the test... the grounding standards were installed.. thoroughly.. top to bottom... and underground, Inside the building and outside.... then it was inspected not once.. but three times, the last time, was just a few weeks prior to the true test. What was the real true test? It was not one.. but SIX strikes to the tower, seperated by by not less than 2 minutes and not more than 10 minutes apart, all from the same thundershower, accompanied by wind shear and less than a half inch of rain, hail, and a flurry of snow. Now.. after all that... the damages to the tower? none. building - none, radios - none. my nerves... a wreck. I watched the lightning hit, and noting the time, so I would be able to fill out the response reports and trouble tickets, and invoice correctly... but that t
ime note... was never needed. The 16 radios on site, didn't even hiccup. Not nary nothing.
I figure that if a commercial site, that has to be on, and in use during a thunder storm can be made to do that.. then my little radio, that I have worked deligently to get on the air, and enjoy so much... doesn't deserve to be left to the whim of a whole herd of out of control electrons on a rampage. And sometimes... sometimes it is a real blast to not have to pull the plug, when the thunder announces that there is Lightning withing 5 miles. ... I don't recommend it tho... but it is nice to know that I don't HAVE to pull all the plugs RIGHT NOW....

Have a great day,
--... ...-- Dale - WC7S in Wy

> > > I understand the technical reasons that people suggest for grounding but I do not see the need.
> > > I have no problems.

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Don Wilhelm-4

Groundi loops

In reply to this post by Jim Brown-10

Jim,

You are correct, the term "ground loop" is not meaningful.

Eric, please excuse this post - I know you have ended the thread (and I
changed the subject), but I fear many have become confused about my
comments because private responses related them to the specifics of the
Mac computers - my emphasis has nothing to do with the Mac, or any other
computer - it encompasses everything in the ham station, or within reach
of the operating position, be that a computer or a table lamp.

The real problem is the difference between the various grounds in the
typical ham station.
One piece of equipment is grounded through the AC mains ground, and
another piece of equipment is grounded to what the operator considers
the "RF Ground" (it is usually not an effective RF Ground, but that is
material for another discussion). If that "RF Ground" is not connected
to the AC Mains ground by a low impedance conductor to the Utility
entrance ground, that may present a dangerous situation simply because
there is resistance between the two grounds. A surge event (lightning,
rain, wind or rain static) can produce a substantial potential
difference between the chassis of "supposedly grounded" pieces of
equipment in the shack because the resistance between the grounds is
finite - it will not be zero, and the surge currents can be very large
(thousands of amperes).

The main consideration is to keep everything in the operating position
at the same potential, and that depends on connecting everything that
can be touched from the operating position together to a single point
common. That common point may be 1000 volts above something which we
normally call "ground" during a surge event, but if it is all at the
same potential, no problem exists (I exaggerated the voltage for the
sake of clarity) - the operator will be safe.

BUT that includes everything within the "touch" region of the hamshack.
Extend your arms out as far as possible from your operating position and
think about what would happen if there was a potential difference
between any two objects - include table lamps, telephones, radios, and
anything else within reach.

The only way to make the operating position safe from a fault condition
or a surge event is to have everything at the same potential, and that
means connecting everything to a common ground point - that means
everything, no exceptions (even the Mac computers).

As Jim Brown has pointed out numerous times, that also cures many hum
and RFI problems too - but that is not my primary concern - the safety
of each and every ham is my main concern.

Even though you may have not had any problems in the past, it has been
said that the time you discover you have a problem, it may be too late.
We do not need any unnecessary silent keys within the ham community, so
be safe and bond things together, and most importantly, if you have
ground rods that are not connected to the utility entry ground rod by a
low impedance conductor (#4 or #6 copper wire), please correct that as
soon as possible, you life may depend on it.

73,
Don W3FPR

On 4/12/2011 3:04 PM, Jim Brown wrote:

> On 4/12/2011 11:07 AM, Edward R. Cole wrote:
>> None of my computer chassis are grounded directly to my radio
>> grounds. I made it especially that way to avoid audio ground
>> loops.
> That's why I abhor the phrase "ground loop" -- it causes people to do
> exactly the WRONG thing, just as you have done. AC hum, buzz, and RFI
> are CAUSED by not bonding together equipment that is interconnected.
> Study the tutorials in the links I posted yesterday to understand why.
>
> And, as W3FPR has observed, this same lack of bonding that causes hum,
> buzz, and RFI also can cause severe damage in the case of a lightning
> strike or power line spike.
>
> Bottom line -- bonding equipment together, bonding it to your station
> ground, and bonding your station ground to all other grounds in your
> home, are critical both for lightning safety and for minimizing hum,
> buzz, and RFI. Most important -- ERASE THE PHRASE "GROUND LOOP" FROM
> YOUR VOCABULARY!
>
> 73, Jim Brown K9YC
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Rick Dettinger-3

Re: Groundi loops

Thanks, Don. I am always happy to learn that something I don't
understand is meaningless! I even like to think that was the reason
that I didn't understand it!

73,
Rick Dettinger K7MW

On Apr 12, 2011, at 8:02 PM, Don Wilhelm wrote:

> Jim,
>
> You are correct, the term "ground loop" is not meaningful.

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Joe Subich, W4TV-4

Re: Groundi loops

In reply to this post by Don Wilhelm-4

> Even though you may have not had any problems in the past, it has
> been said that the time you discover you have a problem, it may be
> too late. We do not need any unnecessary silent keys within the ham
> community, so be safe and bond things together, and most importantly,
> if you have ground rods that are not connected to the utility entry
> ground rod by a low impedance conductor (#4 or #6 copper wire),
> please correct that as soon as possible, you life may depend on it.

Please, take this to heart! Consider the heat generated in the
entire electrical system of your home if your tower is not properly
bonded to the utility ground and the tower takes a lightning strike
at 2AM while you and your loved ones are asleep. Even if the whole
"safety ground" has *only* 0.1 Ohm of resistance, if just 1000 A
makes it through your coax to the safety ground, that's 100 KW of
heat to be dissipated in the wiring and walls of your home.

Be safe. Ground all towers, take all feedlines *completely* to the
ground, bond the shields to the tower and tower ground system at
the base of the tower. Bond the tower/tower ground, the "entry
window" (where the feedlines enter the building) and the utility
ground together *OUTSIDE THE BUILDING*. Encourage any lightning
induced surge to stay outside your home whether it originates on
your antennas/towers or on the utility lines.

73,

... Joe, W4TV

On 4/12/2011 11:02 PM, Don Wilhelm wrote:

> Jim,
>
> You are correct, the term "ground loop" is not meaningful.
>
> Eric, please excuse this post - I know you have ended the thread (and I
> changed the subject), but I fear many have become confused about my
> comments because private responses related them to the specifics of the
> Mac computers - my emphasis has nothing to do with the Mac, or any other
> computer - it encompasses everything in the ham station, or within reach
> of the operating position, be that a computer or a table lamp.
>
> The real problem is the difference between the various grounds in the
> typical ham station.
> One piece of equipment is grounded through the AC mains ground, and
> another piece of equipment is grounded to what the operator considers
> the "RF Ground" (it is usually not an effective RF Ground, but that is
> material for another discussion). If that "RF Ground" is not connected
> to the AC Mains ground by a low impedance conductor to the Utility
> entrance ground, that may present a dangerous situation simply because
> there is resistance between the two grounds. A surge event (lightning,
> rain, wind or rain static) can produce a substantial potential
> difference between the chassis of "supposedly grounded" pieces of
> equipment in the shack because the resistance between the grounds is
> finite - it will not be zero, and the surge currents can be very large
> (thousands of amperes).
>
> The main consideration is to keep everything in the operating position
> at the same potential, and that depends on connecting everything that
> can be touched from the operating position together to a single point
> common. That common point may be 1000 volts above something which we
> normally call "ground" during a surge event, but if it is all at the
> same potential, no problem exists (I exaggerated the voltage for the
> sake of clarity) - the operator will be safe.
>
> BUT that includes everything within the "touch" region of the hamshack.
> Extend your arms out as far as possible from your operating position and
> think about what would happen if there was a potential difference
> between any two objects - include table lamps, telephones, radios, and
> anything else within reach.
>
> The only way to make the operating position safe from a fault condition
> or a surge event is to have everything at the same potential, and that
> means connecting everything to a common ground point - that means
> everything, no exceptions (even the Mac computers).
>
> As Jim Brown has pointed out numerous times, that also cures many hum
> and RFI problems too - but that is not my primary concern - the safety
> of each and every ham is my main concern.
>
> Even though you may have not had any problems in the past, it has been
> said that the time you discover you have a problem, it may be too late.
> We do not need any unnecessary silent keys within the ham community, so
> be safe and bond things together, and most importantly, if you have
> ground rods that are not connected to the utility entry ground rod by a
> low impedance conductor (#4 or #6 copper wire), please correct that as
> soon as possible, you life may depend on it.
>
> 73,
> Don W3FPR
>
> On 4/12/2011 3:04 PM, Jim Brown wrote:
>> On 4/12/2011 11:07 AM, Edward R. Cole wrote:
>>> None of my computer chassis are grounded directly to my radio
>>> grounds. I made it especially that way to avoid audio ground
>>> loops.
>> That's why I abhor the phrase "ground loop" -- it causes people to do
>> exactly the WRONG thing, just as you have done. AC hum, buzz, and RFI
>> are CAUSED by not bonding together equipment that is interconnected.
>> Study the tutorials in the links I posted yesterday to understand why.
>>
>> And, as W3FPR has observed, this same lack of bonding that causes hum,
>> buzz, and RFI also can cause severe damage in the case of a lightning
>> strike or power line spike.
>>
>> Bottom line -- bonding equipment together, bonding it to your station
>> ground, and bonding your station ground to all other grounds in your
>> home, are critical both for lightning safety and for minimizing hum,
>> buzz, and RFI. Most important -- ERASE THE PHRASE "GROUND LOOP" FROM
>> YOUR VOCABULARY!
>>
>> 73, Jim Brown K9YC
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Dick Williams-2

Re: Ligntning protection

In reply to this post by daleputnam

Dale,

I have a good friend (Mike Higgins K6AER) who worked on "lightning proofing"
cell tower sights; and I can say you both really understand the importance
of good grounding!!

I have the good fortune (not so good in thunderstorms) to live on top of a
hill (6700 ft) south of Denver. Over the years I have erected an "antenna
farm", and devoted quite a bit of time working on (with Mikes help) the
lightning protection issue.

To the best of my knowledge, my work has paid off; to date (knock on wood) I
have not had any damage from lightning (and more than one time I have
forgotten to disconnect my equipment). I can't verify that I have been hit
since I started putting up my "farm" in 1994, but a few years ago one of my
neighbors called after we arrived home from an evening out to let me know
the fire dept had been at my house an hour or so ago. I called the
dispatcher, and he told me that a couple of individuals saw one of my towers
take a hit, and called it in. He told me they responded to check out our
house; and after talking to him, I checked out my equipment and everything
seemed to work just fine (coax and rotor lines were disconnected, but
everything was plugged in).

Mike lives about 5 miles from me, and knows he has taken a few hits over the
years; and to date, has not suffered in damage. However, he has also taken
the time to adequately ground his station and tower.

As you and I both know, one ground rod pounded in the ground right outside
the shack is not going to do the trick; it is not going to dissipate the
charge. I think the real "issue" for the vast majority of amateurs is, they
do not have the necessary real-estate to install a good ground system; and
second, the cost to do so (especially with today's prices for copper), is a
fairly expensive endeavor. Additionally, you have to evaluate the "risk";
I lived in Central CA for ten years (79-89), and had two or three ground
rods pounded in the ground. But we had less than one storm a year, so the
risk was low; and I didn't have the land to really have a good system
anyway.

Dick K8ZTT
Franktown, CO

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Dale Putnam
Sent: Tuesday, April 12, 2011 8:58 PM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Ligntning protection

After spending a career chasing storms, each summer, following them, strike
by strike, repairing the damages to commercial communicatins radio systems,
and wishing deeply that there were a way to avoid the waste of time and
resources in repairing the inevitable lightning damage.... Motorola gathered
together, and published their R56 grounding standard, Polyphaser, a company
that has made many an engineering carreer paid for, by placing arrestors in
line... published a number of white papers on the subject...
I then had the oppurtunity to embrace this information, and put it to a
test. The very same tower site, that had previously taken one strike and
damaged three stations, one beyond repair, was put to the test... the
grounding standards were installed.. thoroughly.. top to bottom... and
underground, Inside the building and outside.... then it was inspected not
once.. but three times, the last time, was just a few weeks prior to the
true test. What was the real true test? It was not one.. but SIX strikes to
the tower, seperated by by not less than 2 minutes and not more than 10
minutes apart, all from the same thundershower, accompanied by wind shear
and less than a half inch of rain, hail, and a flurry of snow. Now.. after
all that... the damages to the tower? none. building - none, radios - none.
my nerves... a wreck. I watched the lightning hit, and noting the time, so I
would be able to fill out the response reports and trouble tickets, and
invoice correctly... but that t
ime note... was never needed. The 16 radios on site, didn't even hiccup.
Not nary nothing.
I figure that if a commercial site, that has to be on, and in use during a
thunder storm can be made to do that.. then my little radio, that I have
worked deligently to get on the air, and enjoy so much... doesn't deserve to
be left to the whim of a whole herd of out of control electrons on a
rampage. And sometimes... sometimes it is a real blast to not have to pull
the plug, when the thunder announces that there is Lightning withing 5
miles. ... I don't recommend it tho... but it is nice to know that I don't
HAVE to pull all the plugs RIGHT NOW....

Have a great day,
--... ...-- Dale - WC7S in Wy

> > > I understand the technical reasons that people suggest for grounding
but I do not see the need.
> > > I have no problems.

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John K9UWA-2

Re: Ligntning protection

As Dale stated Polyphaser is the way to go guys.

As to the RISK. I live in Northern Indiana where thunder and lightning are common many times per year. I have three
towers with the top antenna at 175 foot level. Trees here barely make it to 70 feet. So I am IT. There is no DISCONNECT
during such storms. If I ever disconnected this station it would take a couple weeks to do so. Longer to reconnect it. 5 rotors on the
three towers. Twenty Aluminum Yagi antennas for 40-10 meters plus numerous wire antennas. Relay control lines to switch all this
stuff.

After a rather nasty strike back in 1988 when I first installed a good share of this stuff. Insurance claim was close to 10K. Insurance
company said: We don't want you. We did find an Assigned Risk Company who took us. They said 90 days to either get all that
stuff on the ground or install a commercial ground system.

Yes its lots of work and no its not cheap but let me tell you it does WORK. As Dale stated the Tower has been direct hit many
times since 1988. Nothing is ever disconnected. Zero Damage has happened. Yes there are 100 ground rods buried in my yard.
Yes they are connected by 1200 feet of copper 3/8" ID Tubing. It has a lower inductance per foot than 2 inch wide copper strap.
Plus its cheaper. Same stuff as used to hook up AC systems with. I thought I owned STOCK in Polyphaser for a while.

Contesters maybe used to recognize my callsign K9UWA and today they will recognize K9NW Mike as he operates the station in
many contests. All with today one little K3 radio. I operate it remotely during the winters from Florida myself.

so YES you can protect your whole station if you are willing to spend a little money and do a little WORK. Certainly beats the
alternative of trying to find all the things that are messed up after Mother Nature takes its course. The expense really isn't all that
great when compared to the cost of the radios, amplifiers, computers, TV sets, refrigerators and other things that are blown up by
the lightning hits.

It is a scary spectacular display when the tower is hit just after dark. Once it happened when we had a birthday party here with
about 40 friends present. About 1/2 of them were Hams. I think some needed a change of underwear afterwards.

John k9uwa
John Goller, K9UWA & Jean Goller, N9PXF
Antique Radio Restorations
[hidden email]
Visit our Web Site at:
http://www.JohnJeanAntiqueRadio.com
4836 Ranch Road
Leo, IN 46765
USA
1-260-637-6426

______________________________________________________________
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Pete Smith N4ZR

Re: Lightning protection

In reply to this post by daleputnam

I think the problem is that many of our shacks are not ideally situated,
and the grounding standards cannot be fully implemented. Mine, for
example, is on the second floor of an old house. A low inductance
ground is impossible to come by up here, and while I believe the
engineering theory about all grounds rising and lowering together, I
don't want to risk my precious radios to what may be an imperfect
implementation.

Since my ham station doesn't need to stay on the air 24/7, I simply
disconnect everything - every control cable and coax - at the entry into
the shack. I've only had one direct strike in the 15 years my tower has
been up. In the shack, the noise was impressive, and all the coax
barrel connectors arced, adding a little ozone to the atmosphere.
Rotators and switching on the tower was damaged or destroyed, but inside
the shack nothing was affected, except for a computer on a wired
network, killed by induced EMP on a 75-foot network cable. Needless to
say, my network is wireless now.

73, Pete N4ZR

The World Contest Station Database, updated daily at www.conteststations.com
The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com,
spots at telnet.reversebeacon.net, port 7000

On 4/12/2011 10:57 PM, Dale Putnam wrote:
> After spending a career chasing storms, each summer, following them, strike by strike, repairing the damages to commercial communicatins radio systems, and wishing deeply that there were a way to avoid the waste of time and resources in repairing the inevitable lightning damage.... Motorola gathered together, and published their R56 grounding standard, Polyphaser, a company that has made many an engineering carreer paid for, by placing arrestors in line... published a number of white papers on the subject...
> I then had the oppurtunity to embrace this information, and put it to a test. The very same tower site, that had previously taken one strike and damaged three stations, one beyond repair, was put to the test... the grounding standards were installed.. thoroughly.. top to bottom... and underground, Inside the building and outside.... then it was inspected not once.. but three times, the last time, was just a few weeks prior to the true test. What was the real true test? It was not one.. but SIX strikes to the tower, seperated by by not less than 2 minutes and not more than 10 minutes apart, all from the same thundershower, accompanied by wind shear and less than a half inch of rain, hail, and a flurry of snow. Now.. after all that... the damages to the tower? none. building - none, radios - none. my nerves... a wreck. I watched the lightning hit, and noting the time, so I would be able to fill out the response reports and trouble tickets, and invoice correctly... but tha
t t

> ime note... was never needed. The 16 radios on site, didn't even hiccup. Not nary nothing.
> I figure that if a commercial site, that has to be on, and in use during a thunder storm can be made to do that.. then my little radio, that I have worked deligently to get on the air, and enjoy so much... doesn't deserve to be left to the whim of a whole herd of out of control electrons on a rampage. And sometimes... sometimes it is a real blast to not have to pull the plug, when the thunder announces that there is Lightning withing 5 miles. ... I don't recommend it tho... but it is nice to know that I don't HAVE to pull all the plugs RIGHT NOW....
>
> Have a great day,
> --... ...-- Dale - WC7S in Wy
>
>
>
>>>> I understand the technical reasons that people suggest for grounding but I do not see the need.
>>>> I have no problems.
>
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George Danner

Re: Ligntning protection

In reply to this post by Dick Williams-2

After 40 years in South Florida (lightning capital of the US) in a 24/7
business with multiple towers from 50' to 1,000' , my attack for protection
from lightning was to have a massive ground system with extremely low
impedance as well as extremely low resistance in the ground system. A ground
wire that has a bend in it has impedance! A 10' rod is not a ground for
lighting. A ring with many rods works much better. Use a "star" system to
interconnect the equipment; although I believe the cell industry has had
very good success with "Ring-Halo" ground systems. Once that is done then
consider a Dissipation Array. I believe that they reduced our exposure to
damage considerably.

Signal cables should be appropriately protected if they span the ground
system. Almost all signal wire do span the ground system in one way or
other. At ham power levels that would include the RF as well as control &
audio.

When you see multiple strikes hit a tower and do not have to fix anything -
it is a good feeling to know that it all got to the earth without stopping
in any of the equipment.

My 2 cents

George
AI4VZ

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k2zf50

Re: Ligntning protection

In reply to this post by Dick Williams-2

Hi,
My question is what can you do if you live in a rental situation where you don't have the real estate or permission to put in a commercial quality ground system. The landlord permits a 3 element Yagi on the roof but says no to digging up his property for the ground system. What is the best way around this situation?
Thanks,
Jim Douglas K2ZF

-----Original Message-----
From: Dick <[hidden email]>
To: 'Dale Putnam' <[hidden email]>; elecraft <[hidden email]>
Sent: Tue, Apr 12, 2011 8:27 pm
Subject: Re: [Elecraft] Ligntning protection

Dale,

I have a good friend (Mike Higgins K6AER) who worked on "lightning proofing"
cell tower sights; and I can say you both really understand the importance
of good grounding!!

I have the good fortune (not so good in thunderstorms) to live on top of a
hill (6700 ft) south of Denver. Over the years I have erected an "antenna
farm", and devoted quite a bit of time working on (with Mikes help) the
lightning protection issue.

To the best of my knowledge, my work has paid off; to date (knock on wood) I
have not had any damage from lightning (and more than one time I have
forgotten to disconnect my equipment). I can't verify that I have been hit
since I started putting up my "farm" in 1994, but a few years ago one of my
neighbors called after we arrived home from an evening out to let me know
the fire dept had been at my house an hour or so ago. I called the
dispatcher, and he told me that a couple of individuals saw one of my towers
take a hit, and called it in. He told me they responded to check out our
house; and after talking to him, I checked out my equipment and everything
seemed to work just fine (coax and rotor lines were disconnected, but
everything was plugged in).

Mike lives about 5 miles from me, and knows he has taken a few hits over the
years; and to date, has not suffered in damage. However, he has also taken
the time to adequately ground his station and tower.

As you and I both know, one ground rod pounded in the ground right outside
the shack is not going to do the trick; it is not going to dissipate the
charge. I think the real "issue" for the vast majority of amateurs is, they
do not have the necessary real-estate to install a good ground system; and
second, the cost to do so (especially with today's prices for copper), is a
fairly expensive endeavor. Additionally, you have to evaluate the "risk";
I lived in Central CA for ten years (79-89), and had two or three ground
rods pounded in the ground. But we had less than one storm a year, so the
risk was low; and I didn't have the land to really have a good system
anyway.

Dick K8ZTT
Franktown, CO

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Dale Putnam
Sent: Tuesday, April 12, 2011 8:58 PM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] Ligntning protection

After spending a career chasing storms, each summer, following them, strike
by strike, repairing the damages to commercial communicatins radio systems,
and wishing deeply that there were a way to avoid the waste of time and
resources in repairing the inevitable lightning damage.... Motorola gathered
together, and published their R56 grounding standard, Polyphaser, a company
that has made many an engineering carreer paid for, by placing arrestors in
line... published a number of white papers on the subject...
I then had the oppurtunity to embrace this information, and put it to a
test. The very same tower site, that had previously taken one strike and
damaged three stations, one beyond repair, was put to the test... the
grounding standards were installed.. thoroughly.. top to bottom... and
underground, Inside the building and outside.... then it was inspected not
once.. but three times, the last time, was just a few weeks prior to the
true test. What was the real true test? It was not one.. but SIX strikes to
the tower, seperated by by not less than 2 minutes and not more than 10
minutes apart, all from the same thundershower, accompanied by wind shear
and less than a half inch of rain, hail, and a flurry of snow. Now.. after
all that... the damages to the tower? none. building - none, radios - none.
my nerves... a wreck. I watched the lightning hit, and noting the time, so I
would be able to fill out the response reports and trouble tickets, and
invoice correctly... but that t
ime note... was never needed. The 16 radios on site, didn't even hiccup.
Not nary nothing.
I figure that if a commercial site, that has to be on, and in use during a
thunder storm can be made to do that.. then my little radio, that I have
worked deligently to get on the air, and enjoy so much... doesn't deserve to
be left to the whim of a whole herd of out of control electrons on a
rampage. And sometimes... sometimes it is a real blast to not have to pull
the plug, when the thunder announces that there is Lightning withing 5
miles. ... I don't recommend it tho... but it is nice to know that I don't
HAVE to pull all the plugs RIGHT NOW....

Have a great day,
--... ...-- Dale - WC7S in Wy

> > > I understand the technical reasons that people suggest for grounding
but I do not see the need.
> > > I have no problems.

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Kurt Pawlikowski

Re: Ligntning protection

In reply to this post by John K9UWA-2

John, Dick, Dale, Et Al,

Very interesting discussion! I'm sure this has come up before: Just
one question: Where would one find good information on-line about proper
grounding.

Thanks!

Regards,

kurtt

Kurt Pawlikowski
The Pinrod Corporation
[hidden email]
(773) 284-9500
http://pinrod.com

On 4/13/2011 00:24, John K9UWA wrote:

> As Dale stated Polyphaser is the way to go guys.
>
> As to the RISK. I live in Northern Indiana where thunder and lightning are common many times per year. I have three
> towers with the top antenna at 175 foot level. Trees here barely make it to 70 feet. So I am IT. There is no DISCONNECT
> during such storms. If I ever disconnected this station it would take a couple weeks to do so. Longer to reconnect it. 5 rotors on the
> three towers. Twenty Aluminum Yagi antennas for 40-10 meters plus numerous wire antennas. Relay control lines to switch all this
> stuff.
>
> After a rather nasty strike back in 1988 when I first installed a good share of this stuff. Insurance claim was close to 10K. Insurance
> company said: We don't want you. We did find an Assigned Risk Company who took us. They said 90 days to either get all that
> stuff on the ground or install a commercial ground system.
>
> Yes its lots of work and no its not cheap but let me tell you it does WORK. As Dale stated the Tower has been direct hit many
> times since 1988. Nothing is ever disconnected. Zero Damage has happened. Yes there are 100 ground rods buried in my yard.
> Yes they are connected by 1200 feet of copper 3/8" ID Tubing. It has a lower inductance per foot than 2 inch wide copper strap.
> Plus its cheaper. Same stuff as used to hook up AC systems with. I thought I owned STOCK in Polyphaser for a while.
>
> Contesters maybe used to recognize my callsign K9UWA and today they will recognize K9NW Mike as he operates the station in
> many contests. All with today one little K3 radio. I operate it remotely during the winters from Florida myself.
>
> so YES you can protect your whole station if you are willing to spend a little money and do a little WORK. Certainly beats the
> alternative of trying to find all the things that are messed up after Mother Nature takes its course. The expense really isn't all that
> great when compared to the cost of the radios, amplifiers, computers, TV sets, refrigerators and other things that are blown up by
> the lightning hits.
>
> It is a scary spectacular display when the tower is hit just after dark. Once it happened when we had a birthday party here with
> about 40 friends present. About 1/2 of them were Hams. I think some needed a change of underwear afterwards.
>
> John k9uwa
> John Goller, K9UWA& Jean Goller, N9PXF
> Antique Radio Restorations
> [hidden email]
> Visit our Web Site at:
> http://www.JohnJeanAntiqueRadio.com
> 4836 Ranch Road
> Leo, IN 46765
> USA
> 1-260-637-6426
>
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Randy Moore

Re: Ligntning protection

Sorry if someone has already asked this. My shack is on the second floor of my home and is on the opposite corner of the house from where the electrical power entry and ground are located. However, the electrical panel is in the garage right below my shack. Can I connect my shack ground to the panel ground instead of running a ~200' long line to the electrical ground on the other end of the house?

Tnx es 73,
Randy, KS4L
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Fred Townsend

Re: Ligntning protection

Randy:
I can not speak to your local building codes but the rule of thumb is
lightning does not like to travel horizontally. That doesn't mean it won't
happen but usually lightning seeks the shortest path to ground. That
suggests you should connect to the closest ground (exception: any fuel
line).
If possible I would drive my own ground rod below the shack and use the
garage ground as well. There is no penalty for extra grounds.

73
de AE6QL, Fred

-----Original Message-----
From: Randy Moore [mailto:[hidden email]]
Sent: Wednesday, April 13, 2011 8:15 AM
To: [hidden email]
Subject: Re: [Elecraft] Ligntning protection

Sorry if someone has already asked this. My shack is on the second floor of
my home and is on the opposite corner of the house from where the electrical
power entry and ground are located. However, the electrical panel is in the
garage right below my shack. Can I connect my shack ground to the panel
ground instead of running a ~200' long line to the electrical ground on the
other end of the house?

Tnx es 73,
Randy, KS4L
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Steve Ellington

Re: Ligntning protection

Question:
Does grounding your tower or metal mast increase the likelihood of it being
hit by lightning?
I have a 50' metal mast holding up the center of a dipole. No antenna
contacts the mast and the ant. is supported by rope. Should I drive in a
ground rod just for the mast? If I do, would lightning be attracted to it
then? It just seems like I'm inviting a hit by grounding it.

Steve
N4LQ
----- Original Message -----
From: "Fred Townsend" <[hidden email]>
To: "'Randy Moore'" <[hidden email]>; <[hidden email]>
Sent: Wednesday, April 13, 2011 12:19 PM
Subject: Re: [Elecraft] Ligntning protection

> Randy:
> I can not speak to your local building codes but the rule of thumb is
> lightning does not like to travel horizontally. That doesn't mean it won't
> happen but usually lightning seeks the shortest path to ground. That
> suggests you should connect to the closest ground (exception: any fuel
> line).
> If possible I would drive my own ground rod below the shack and use the
> garage ground as well. There is no penalty for extra grounds.
>
> 73
> de AE6QL, Fred
>
> -----Original Message-----
> From: Randy Moore [mailto:[hidden email]]
> Sent: Wednesday, April 13, 2011 8:15 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Ligntning protection
>
> Sorry if someone has already asked this. My shack is on the second floor
> of
> my home and is on the opposite corner of the house from where the
> electrical
> power entry and ground are located. However, the electrical panel is in
> the
> garage right below my shack. Can I connect my shack ground to the panel
> ground instead of running a ~200' long line to the electrical ground on
> the
> other end of the house?
>
> Tnx es 73,
> Randy, KS4L
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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Re: Ligntning protection

No, it will drain the electrostatic field in the vacinity and make it less
likely to get hit. I have watched lightning strike my neighbor's 15 ft brick
chimney about 100 ft away from my well grounded 70 ft tower with two beams
installed. The better the grounding, the better and bonding it to the power
entrance ground is a good thing as well.
Willis 'Cookie' Cooke
K5EWJ

________________________________
From: Steve Ellington <[hidden email]>
To: Fred Townsend <[hidden email]>; Randy Moore <[hidden email]>;
[hidden email]
Sent: Thu, April 21, 2011 2:27:46 PM
Subject: Re: [Elecraft] Ligntning protection

Question:
Does grounding your tower or metal mast increase the likelihood of it being
hit by lightning?
I have a 50' metal mast holding up the center of a dipole. No antenna
contacts the mast and the ant. is supported by rope. Should I drive in a
ground rod just for the mast? If I do, would lightning be attracted to it
then? It just seems like I'm inviting a hit by grounding it.

Steve
N4LQ
----- Original Message -----
From: "Fred Townsend" <[hidden email]>
To: "'Randy Moore'" <[hidden email]>; <[hidden email]>
Sent: Wednesday, April 13, 2011 12:19 PM
Subject: Re: [Elecraft] Ligntning protection

Phil LaMarche-2

Re: Ligntning protection

I absolutely agree. I have a deep heavy ground rod right outside my window.
Have a 4 inch copper strap coming into the shack where all pieces of
equipment are individually grounded to this. Outside, the ground rod is
attached to # 4 wire that goes to the house ground and to the 70 Ft tower.
Then I have 6 ground rods around the tower that attach to the tower. Also
have ground rods every 15 ft attached to the wire going to the house ground.
I have had two direct hits and never lost a piece of equipment except for
the traps on the Mosley PRO67B-3. I too have seen hits near the house. I
know I am just lucky but tried to do the best I could with the grounding.
Plus I have ARRL insurance.

Phil

Philip LaMarche

LaMarche Enterprises, Inc
[hidden email]
www.LaMarcheEnterprises.com

727-944-3226
727-937-8834 Fax
727-510-5038 Cell

www.w9dvm.com

K3 #1605

CCA 98-00827
CRA 1701
W9DVM

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of WILLIS COOKE
Sent: Thursday, April 21, 2011 3:46 PM
To: Steve Ellington; Elecraft Reflector
Subject: Re: [Elecraft] Ligntning protection

No, it will drain the electrostatic field in the vacinity and make it less
likely to get hit. I have watched lightning strike my neighbor's 15 ft
brick chimney about 100 ft away from my well grounded 70 ft tower with two
beams installed. The better the grounding, the better and bonding it to the
power entrance ground is a good thing as well.
Willis 'Cookie' Cooke
K5EWJ

________________________________
From: Steve Ellington <[hidden email]>
To: Fred Townsend <[hidden email]>; Randy Moore
<[hidden email]>; [hidden email]
Sent: Thu, April 21, 2011 2:27:46 PM
Subject: Re: [Elecraft] Ligntning protection

Question:
Does grounding your tower or metal mast increase the likelihood of it being
hit by lightning?
I have a 50' metal mast holding up the center of a dipole. No antenna
contacts the mast and the ant. is supported by rope. Should I drive in a
ground rod just for the mast? If I do, would lightning be attracted to it
then? It just seems like I'm inviting a hit by grounding it.

Steve
N4LQ
----- Original Message -----
From: "Fred Townsend" <[hidden email]>
To: "'Randy Moore'" <[hidden email]>; <[hidden email]>
Sent: Wednesday, April 13, 2011 12:19 PM
Subject: Re: [Elecraft] Ligntning protection

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k6dgw

Re: Ligntning protection

In reply to this post by Steve Ellington

Lightning is about as predictable as your average teenager. It is very
[very!] common for cloud-to-ground strikes to start with a
ground-to-cloud "leader." You can't see it and it happens fairly fast
[but nowhere near as fast as the main strike]. It builds an ionization
path when the main strike then follows from the cloud to the ground ...
at least part-way.

So, one could surmise that a ground rod connected to your mast would
offer a desirable path for the leader current and thus "attract" a
strike. Whether or not this will happen depends on where the ground
charge has accumulated [usually but not always under the guilty cloud],
whether or not your ground rod actually *is* a desirable path, what else
is around your mast, and a host of other unpredictable things. A rod
stuck in the earth makes a very problematical connection to "ground."

The fact that the apex of the mast is not connected to your antenna is
not relevant for a strike, although it is relevant for precip static.
If a few megavolts decides to land on your "grounded" mast, it will all
become connected and a few microseconds later, be vaporized.

73,

Fred K6DGW

On 4/21/2011 7:27 PM, Steve Ellington wrote:
> Question:
> Does grounding your tower or metal mast increase the likelihood of it being
> hit by lightning?
> I have a 50' metal mast holding up the center of a dipole. No antenna
> contacts the mast and the ant. is supported by rope. Should I drive in a
> ground rod just for the mast? If I do, would lightning be attracted to it
> then? It just seems like I'm inviting a hit by grounding it.

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123