If I understand correctly the just of these replies, -- I would be better
off if I installed a so-called "stand-alone" ground rod that was several
feet a way from the ground rod that my home was on and use this
"stand-alone" ground rod solely for my shack equipment, and then driving
another ground rod by my Butternut vertical and connecting it to the antenna
ground rod. Am I correct in this? What is confusing to me is what one of
the replies suggested that the rods be bonded or connected together. If that
is a correct thing to do I don't see what the difference would be to using a
single ground rod. After-all a ground rod is a ground rod.
Thanks again for all your help.
73's




" wrote in message news:zHhae.4351$lz1.2472@lakeread01...

"gb" wrote
in message ...
"Dave Platt" wrote in message
...
In article ,
Rob Collis wrote:

Hi Joe,
IMHO it is best to isolate the ground used in the shack from the
household
ground. This should reduce noise from any mains supplied appliances.
You
could use a third rod for the antenna no problem.

In the United States, most localities incorporate the National
Electric Code into their own local building codes. It is my
understanding that the NEC requires that each building structure have
precisely one "ground system", and that this requires that all ground
rods be reliably "bonded" together (typically via 6-gauge-or-heavier
wire).

The ground-system bonding is required in order to reduce the degree to
which ground-voltage differentials can occur in the case of an
electrical fault or nearby lighting strike. The bonding reduces the
current that can flow through appliances that are connected to two or
more independent "ground" systems (e.g. a building's main electrical
ground, and a separate ground stake near an antenna).

Putting in a second ground rod near the hamshack can be a good idea,
as it reduces the length of the ground wire from rig to ground rod and
can improve the quality of the RF ground (depends a lot on wire length
and frequency). However, in order to comply with the NEC, this ground
rod must be bonded to the main building ground.

I don't know what the rules are in other countries.

--
Dave Platt, AE6EO

Dave is correct about NEC requires, HOWEVER please check with you local
municipal (or country/parish) building department (or code
enforcement) -
there are variations that are more restrictive than NEC in SOME U.S.
localities.

That said, IF you are going to have a tower or large antenna array - RF
grounding needs to be addressed separately from electrical service
grounding. This area also has different requirements in SOME areas (for
example - parts of Florida have the highest lightning hits per year).
Glen
Zook, K9STH has given talks and presentations on this subject - this
information can be found he
http://home.comcast.net/~k9sth/

w9gb

Please, PLEASE, disregard every bit of that RUBBISH about "dissipation"
(prevention) of lightning strikes in K9STH's website. There is not one
single piece of scientific evidence to any of that bullcrap. The theories
of
Charge-transfer-systems (CTS), Early Steamer Emissions (ESE) or ANY kind
of
lightning prevention are total malarkey. The cost of gathering
international
review and wide publication of DIScrediting these phony's is incredible,
but
the IEEE has done so over and over again.

There was good advice in this thread (and one bad one, advising isolation
of
house and radio grounds), until "gb" dragged that old nuttiness about
dissipators out of the closet.

Best regards,

Jack Painter
Virginia Beach, Virginia

Joe,

I didn't just suggest that the grounds be bonded (connected
electrically), the NEC requires it. Placing a ground near your
antenna base and near your shack will provide a path from your
equipment to the ground that is less than a quarter-wave at 30 mHz.
This will help keep the ground wire from radiating. If you do not
comply with the NEC sec. 250 requirement, your insurance carrier has a
case for not paying your claim. Multiple ground rods lower the
impedence to earth in case of a lightning strike. Lightning is
largely RF and will "prefer" a low impedence to earth. Bond the
grounds together with #6 or larger wire. Don't take my word for it,
ask your insurace company. I am a former Telco employee and grounding
there is a religion, and not a minor one. See the BSPs ("Bell System
Practices", now "Best Suggested Practices") and the web site of the
Erico corporation. A. J. Surtees is one of THE authorities on
grounding.

Russ

On Sat, 23 Apr 2005 02:04:29 GMT, "Joe" wrote:

If I understand correctly the just of these replies, -- I would be better
off if I installed a so-called "stand-alone" ground rod that was several
feet a way from the ground rod that my home was on and use this
"stand-alone" ground rod solely for my shack equipment, and then driving
another ground rod by my Butternut vertical and connecting it to the antenna
ground rod. Am I correct in this? What is confusing to me is what one of
the replies suggested that the rods be bonded or connected together. If that
is a correct thing to do I don't see what the difference would be to using a
single ground rod. After-all a ground rod is a ground rod.
Thanks again for all your help.
73's




" wrote in message news:zHhae.4351$lz1.2472@lakeread01...

"gb" wrote
in message ...
"Dave Platt" wrote in message
...
In article ,
Rob Collis wrote:

Hi Joe,
IMHO it is best to isolate the ground used in the shack from the
household
ground. This should reduce noise from any mains supplied appliances.
You
could use a third rod for the antenna no problem.

In the United States, most localities incorporate the National
Electric Code into their own local building codes. It is my
understanding that the NEC requires that each building structure have
precisely one "ground system", and that this requires that all ground
rods be reliably "bonded" together (typically via 6-gauge-or-heavier
wire).

The ground-system bonding is required in order to reduce the degree to
which ground-voltage differentials can occur in the case of an
electrical fault or nearby lighting strike. The bonding reduces the
current that can flow through appliances that are connected to two or
more independent "ground" systems (e.g. a building's main electrical
ground, and a separate ground stake near an antenna).

Putting in a second ground rod near the hamshack can be a good idea,
as it reduces the length of the ground wire from rig to ground rod and
can improve the quality of the RF ground (depends a lot on wire length
and frequency). However, in order to comply with the NEC, this ground
rod must be bonded to the main building ground.

I don't know what the rules are in other countries.

--
Dave Platt, AE6EO

Dave is correct about NEC requires, HOWEVER please check with you local
municipal (or country/parish) building department (or code
enforcement) -
there are variations that are more restrictive than NEC in SOME U.S.
localities.

That said, IF you are going to have a tower or large antenna array - RF
grounding needs to be addressed separately from electrical service
grounding. This area also has different requirements in SOME areas (for
example - parts of Florida have the highest lightning hits per year).
Glen
Zook, K9STH has given talks and presentations on this subject - this
information can be found he
http://home.comcast.net/~k9sth/

w9gb

Please, PLEASE, disregard every bit of that RUBBISH about "dissipation"
(prevention) of lightning strikes in K9STH's website. There is not one
single piece of scientific evidence to any of that bullcrap. The theories
of
Charge-transfer-systems (CTS), Early Steamer Emissions (ESE) or ANY kind
of
lightning prevention are total malarkey. The cost of gathering
international
review and wide publication of DIScrediting these phony's is incredible,
but
the IEEE has done so over and over again.

There was good advice in this thread (and one bad one, advising isolation
of
house and radio grounds), until "gb" dragged that old nuttiness about
dissipators out of the closet.

Best regards,

Jack Painter
Virginia Beach, Virginia

"Joe" wrote
If I understand correctly the just of these replies, --

I'm afraid you still didn't get the gist, Joe...

We could start over:

1.You want to set up shop in a basement.
2. You will have a Butternut vertical antenna nearby.
3. You want to know what should be grounded, and specifically where.
4. You asked about a bus-bar ground panel behind your radios.

We don't know where your main house AC power panel is, or what kind of
ground system it uses (could be the home's cold water supply pipe, a buried
copper plate, or buried copper ground rod). This will be important later,
and as others said, it is generally accepted practice and code in most
countries to require that all systems use either one single grounding point,
or bond any supplemental ground points to it. You should do at least some
basic research on your own about grounding and bonding, if this is not
abundantly clear to you.

Your vertical may or may not require the use of RF radials, counterpoise,
etc. Consult the manufacturers recommendations there, and follow them
exactly. If you do use a radial system or buried copper wires, some common
point of that system must bond to both the home's AC service ground point
*and* the radio equipment's ground rod, if separate ones are used. What you
do with your antenna and radio ground rods are entirely up to you.
Electrical codes do not cover bonding RF grounds and an separate radio
ground rod to each other. But a hundred years of sound lightning protection
science *does* require that you always bond ALL ground systems together,
NEVER leaving them isolated from each other.

It gets very expensive to provide high voltage isolation transformers
capable of safely isolating neutrals and ground systems, and while possible
this is never a goal of the hobbyist. Bonding everything should be your goal
in maintaining the basic forms of lightning protection.

Next, you can consider AC surge protection at both the AC entrance and radio
equipment. This is the protection from surge voltages that nearby lightning
imposes on either the incoming power lines, or magnetically onto the house
wiring.

Included in the category of surge protection are Surge Protection Devices
(most still call these lightning arrestors) that install in-line on your
coaxial or open-wire feedlines. These SPD's limit the amount of damaging
voltage presented to your radio's receiver circuitry.

Coax shield grounding (braid of the coax connected to ground rods at several
points as required) is what keeps damaging voltages off the exterior of the
radios, including your fingers, and limits back-flow of destructive current
out the back of the radios and into your homes AC wiring. The critical
bonding of radio and shield-grounding rods to the homes AC entrance ground
is of major importance here also. If you do not provide a very low impedance
path around your equipment, surge voltages can force one through your
equipment.

A copper bus-bar or other wide low-impedance "collector" of single point
grounding and bond points of all radios can be centered behind your
equipment as you asked. But avoid daisy chaining radios in a series to bond
them. As inconvenient and hard to conceal as it may be, individual bonding
connections from each radio, straight to the single point ground (for the
radio shack) is important. This not only provides the only approved bonding
method for lightning protection, but limits ground-loop noise between
equipments.

Hope this helps tie some of the other good posters comments together.

It's a long read, but I tried to cover most of the points of a total
lightning protection system in this website. It might clear up how important
the bonding is, I hope!

http://members.cox.net/pc-usa/station/ground0.htm

Best regards,

Jack Painter
Virginia Beach, Virginia

On Sat, 23 Apr 2005 00:10:41 -0400, "Jack Painter"
wrote:


"Joe" wrote
If I understand correctly the just of these replies, --

I'm afraid you still didn't get the gist, Joe...

We could start over:

1.You want to set up shop in a basement.
2. You will have a Butternut vertical antenna nearby.
3. You want to know what should be grounded, and specifically where.
4. You asked about a bus-bar ground panel behind your radios.

*** BIG SNIP ***
It's a long read, but I tried to cover most of the points of a total
lightning protection system in this website. It might clear up how important
the bonding is, I hope!

http://members.cox.net/pc-usa/station/ground0.htm

Best regards,

Jack Painter
Virginia Beach, Virginia

Thanks Jack. You did tie (pun) it all together.

Russ