Grounding Question
 

I am installing a G5RV antenna, and a new ground for my TS-2000. The radio
is in the center of the house, and instead of running a long ground wire to
a ground rod at the outside of the house, i was thinking of drilling a hole
directly below the radio room in the basement floor and driving the ground
rod there. That would make the ground wire only 6-8' long. Assuming i do
not find a wastepipe while driving my ground, is there any issues with
getting a HF ground this way?

Also, I was going to install lightning arrestors at the radio and ground
them to the new ground rod, is it better to place the lightning arrestors
and an additional ground rod where the coax enters the house, or will this
cause ground loop issues?

Thanks in advance to the collective wisdom of group.

Gerry KC8ZUL

"Gerry Moersdorf" wrote in message
...
I am installing a G5RV antenna, and a new ground for my TS-2000. The
radio
is in the center of the house, and instead of running a long ground wire
to
a ground rod at the outside of the house, i was thinking of drilling a
hole
directly below the radio room in the basement floor and driving the ground
rod there. That would make the ground wire only 6-8' long. Assuming i do
not find a wastepipe while driving my ground, is there any issues with
getting a HF ground this way?

Also, I was going to install lightning arrestors at the radio and ground
them to the new ground rod, is it better to place the lightning arrestors
and an additional ground rod where the coax enters the house, or will this
cause ground loop issues?

Thanks in advance to the collective wisdom of group.

Gerry KC8ZUL

I was going to install lightning arrestors at the radio and ground
them to the new ground rod, is it better to place the lightning arrestors
and an additional ground rod where the coax enters the house, or will this
cause ground loop issues?

Hi Gerry, You are dealing with two different grounding issues, and I can't
comment on the ground loop one. The purpose of the lightning protection ground
is to make sure that most of the current from a strike gets to ground the way
you want. And you want it NOT to go thru your TS on its way to ground.
A ground directly at the rig can be a safety ground as well as an RF ground.
What you describe sounds like you are trying for an RF ground at the rig and a
safety ground at the entrance to the house. You may not need an RF ground, I
would concentrate on the safety aspect, and add the RF later if needed.

73 Gary N4AST

"Gerry Moersdorf" wrote
I am installing a G5RV antenna, and a new ground for my TS-2000. The
radio
is in the center of the house, and instead of running a long ground wire
to
a ground rod at the outside of the house, i was thinking of drilling a
hole
directly below the radio room in the basement floor and driving the ground
rod there. That would make the ground wire only 6-8' long. Assuming i do
not find a wastepipe while driving my ground, is there any issues with
getting a HF ground this way?

Gerry, if the G5RV is a non-radial using antenna (function is complete, as
in a dipole), then this so called RF ground from your transmitter will be of
little if any use. If you ran ladder line to it directly from the
transmitter or tuner (and you were willing to tolerate RF in your shack and
your home) maybe you do need an RF ground! G Assuming that's not the case,
and you just want an RF ground anyway, the shortest path via minimum 3" wide
copper strap would provide a good one, regardless of its basement location

Also, I was going to install lightning arrestors at the radio and ground
them to the new ground rod, is it better to place the lightning arrestors
and an additional ground rod where the coax enters the house, or will this
cause ground loop issues?

Thanks in advance to the collective wisdom of group.

Gerry KC8ZUL

Here is where you are mixing apples and oranges, because ground loops and
lightning protection are not related. The only time lightning arrestors
should ever be inside the shack is when they are immediately attached to the
station single point ground *when that is inside the shack*. Mine is for
instance, but I am also alongside an outside wall under which is the
entry-point for all coax, and the shield-grounding point for same. If you
are transmitting from an interior room, far from the coax entry point to the
home, then the coax shields should be grounded outside the home and
lightning arrestors installed there. The key is to have the lightning
arrestors on as short a connection to real earth ground as possible.
Preferably within 1' but in no cases more than 4' (via extremely low
impedance and high current capability connectors) from earth ground.

Your location indicates that an outside bulkhead (some call this a "ground
window") might be ideal. This would typically involve a copper plate
attached to the external coax entry point of the home. Bond this bulkhead
immediately to a minimum 5/8" x 8' ground rod (and bury the ground rod top,
do not let it protrude above ground). Ground all coaxial cable shielding to
the ground rod (or *heavy* strap leading to it) and attach the lightning
arrestors directly to the copper bulkhead above that. Then add a second and
third ground rod, each fanning out from the first and a minimum of 12' from
the first (16' is recommended).

If you are able to, install a very heavy (#2 or #4 copper) bonding conductor
from your inside station ground (this might be in your basement) to your
electrical service entry ground. Also bond the AC service entry ground rod
to your outside coax entry grounding bulkhead. *If* you are able to
accomplish that, *and* you have good surge protection installed at 1: the AC
service panel, and 2. the point-of-use in your shack, then it would be safe
to leave the transmitter plugged into AC during a storm. Otherwise, no
matter how good your external grounding bulkhead and attached lightning
arrestors, there will still be a path for enough damaging potential from
ground to your radio, and out through the AC power cable. The critical
bonding conductor from radio to AC service entry helps but cannot eliminate
this path. Without it, there is no safe connection to AC power during a
storm, no matter how good the surge protection is.

You can explore these comments in greater detail at:
http://members.cox.net/pc-usa/station/grounding.htm

73,
Jack

"Jack Painter" wrote in message
news:pzWed.113241$Lo6.35776@fed1read03...
"Gerry Moersdorf" wrote
I am installing a G5RV antenna, and a new ground for my TS-2000. The
radio
is in the center of the house, and instead of running a long ground wire
to
a ground rod at the outside of the house, i was thinking of drilling a
hole
directly below the radio room in the basement floor and driving the
ground
rod there. That would make the ground wire only 6-8' long. Assuming i
do
not find a wastepipe while driving my ground, is there any issues with
getting a HF ground this way?

Gerry, if the G5RV is a non-radial using antenna (function is complete, as
in a dipole), then this so called RF ground from your transmitter will be
of
little if any use. If you ran ladder line to it directly from the
transmitter or tuner (and you were willing to tolerate RF in your shack
and
your home) maybe you do need an RF ground! G Assuming that's not the
case,
and you just want an RF ground anyway, the shortest path via minimum 3"
wide
copper strap would provide a good one, regardless of its basement location

Also, I was going to install lightning arrestors at the radio and ground
them to the new ground rod, is it better to place the lightning
arrestors
and an additional ground rod where the coax enters the house, or will
this
cause ground loop issues?

Thanks in advance to the collective wisdom of group.

Gerry KC8ZUL

Here is where you are mixing apples and oranges, because ground loops and
lightning protection are not related. The only time lightning arrestors
should ever be inside the shack is when they are immediately attached to
the
station single point ground *when that is inside the shack*. Mine is for
instance, but I am also alongside an outside wall under which is the
entry-point for all coax, and the shield-grounding point for same. If you
are transmitting from an interior room, far from the coax entry point to
the
home, then the coax shields should be grounded outside the home and
lightning arrestors installed there. The key is to have the lightning
arrestors on as short a connection to real earth ground as possible.
Preferably within 1' but in no cases more than 4' (via extremely low
impedance and high current capability connectors) from earth ground.

Your location indicates that an outside bulkhead (some call this a "ground
window") might be ideal. This would typically involve a copper plate
attached to the external coax entry point of the home. Bond this bulkhead
immediately to a minimum 5/8" x 8' ground rod (and bury the ground rod
top,
do not let it protrude above ground). Ground all coaxial cable shielding
to
the ground rod (or *heavy* strap leading to it) and attach the lightning
arrestors directly to the copper bulkhead above that. Then add a second
and
third ground rod, each fanning out from the first and a minimum of 12'
from
the first (16' is recommended).

If you are able to, install a very heavy (#2 or #4 copper) bonding
conductor
from your inside station ground (this might be in your basement) to your
electrical service entry ground. Also bond the AC service entry ground rod
to your outside coax entry grounding bulkhead. *If* you are able to
accomplish that, *and* you have good surge protection installed at 1: the
AC
service panel, and 2. the point-of-use in your shack, then it would be
safe
to leave the transmitter plugged into AC during a storm. Otherwise, no
matter how good your external grounding bulkhead and attached lightning
arrestors, there will still be a path for enough damaging potential from
ground to your radio, and out through the AC power cable. The critical
bonding conductor from radio to AC service entry helps but cannot
eliminate
this path. Without it, there is no safe connection to AC power during a
storm, no matter how good the surge protection is.

You can explore these comments in greater detail at:
http://members.cox.net/pc-usa/station/grounding.htm

73,
Jack


Jack and others,

Thanks for the weblink, this helped me understand what is going on with
grounding.

will go for external lightning grounds at feedlines, and extend the AC
safety ground to the shack. will give this a try !

gerry

On Sun, 24 Oct 2004 22:07:18 GMT, "Gerry Moersdorf"
wrote:

i was thinking of drilling a hole
directly below the radio room in the basement floor

Hi Gerry,

This is like punching a hole in the bottom of a boat. Can you guess
what might happen next?

73's
Richard Clark, KB7QHC

Richard Clark wrote:

On Sun, 24 Oct 2004 22:07:18 GMT, "Gerry Moersdorf"
wrote:

i was thinking of drilling a hole
directly below the radio room in the basement floor

Hi Gerry,

This is like punching a hole in the bottom of a boat. Can you guess
what might happen next?

73's
Richard Clark, KB7QHC

A hole through the floor is not always a good idea, especially if the place where you
drill is near the center of the foundation. The soil underneath is probably very dry
and of no value for any sort of ground.

Irv VE6BP
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

On Mon, 25 Oct 2004 03:59:17 GMT, Irv Finkleman
wrote:
A hole through the floor is not always a good idea, especially if the place where you
drill is near the center of the foundation. The soil underneath is probably very dry
and of no value for any sort of ground.

Hi Irv,

One might thinks so (dry), but this is the second hill I've lived on
the top of. The first one had a neighbor who had an underground
spring running through his basement. Here, I have two sump pumps with
a perimeter drain for the same reason.

73's
Richard Clark, KB7QHC

Jack Painter wrote:
"Here is where you are mixing apples and oranges=A0because ground loops
and lightning protection are not related."

A ground loop is a potentially detrimental condition due to two or more
points in an elewctrical system that are nominally at ground potential
being connected by a conducting path.

A ground loop may provide a common impedance which couples energy
between two or more circuits. Strength of the energy in the electrical
circuits is immaterial in a current loop so long as nothing breaks down.
Response to the excitation is the same.

A lightning strike is a huge noise injection. Techniques for noise
reduction and testing are
also applicable to lightning suppression and may be tested with weak
noise signals. I know from personal experience.

It is desirable to avoid common impedances which can couple lightning
from one circuit to another, as a "ground loop" may.

Ground connections for protected equipments can be made with individual
wires between each of the devices and a common ground point to avoid
ground loops. This is not always practical.

It is usually practical to enclose devices inside a conductive
enclosure, then to low-pass filter and surge protect every wire which
penetrates the enclosure.

A screened room can serve as both noise and lightning protection, for
example.

Best regards, Richard Harrison, KB5WZI

Richard Clark wrote:

On Mon, 25 Oct 2004 03:59:17 GMT, Irv Finkleman
wrote:
A hole through the floor is not always a good idea, especially if the place where you
drill is near the center of the foundation. The soil underneath is probably very dry
and of no value for any sort of ground.

Hi Irv,

One might thinks so (dry), but this is the second hill I've lived on
the top of. The first one had a neighbor who had an underground
spring running through his basement. Here, I have two sump pumps with
a perimeter drain for the same reason.

73's
Richard Clark, KB7QHC

Wow! I'm on a hill too, but dry as a bone underneath the foundation. Fortunately
the soil around the house is moist and loamy.
Just wondeing -- is the spring salt water? :-)

Irv
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

"Richard Harrison" wrote
Jack Painter wrote:
"Here is where you are mixing apples and oranges because ground loops
and lightning protection are not related."
--
A ground loop is a potentially detrimental condition due to two or more
points in an elewctrical system that are nominally at ground potential
being connected by a conducting path.

Ground connections for protected equipments can be made with individual
wires between each of the devices and a common ground point to avoid
ground loops. This is not always practical.

It is usually practical to enclose devices inside a conductive
enclosure, then to low-pass filter and surge protect every wire which
penetrates the enclosure.
--

Hi Richard, had I thought that was a controversial statement, I could have
elaborated that elimination of ground loops is normally a radio frequency
interference issue, and the creation of at least one ground loop is a design
requirement in residential lightning protection. The two are not usually
discussed together unless a conflict ocurrs, but I see your point.

It is indeed a requirement to individually bond equipment to the single
point station ground...and yes, practicality allows certain clusters of
equipment to be common bonded within their enclosures as you commented. But
the one place where a ground loop *must* be installed is in the station
ground to electrical service ground bonding. Proper station design requires
these never be far apart from each other in the first place, but we are
talking about residential stations, and close proximity between them is
rarely possible.

Telecom stations that cannot individually bond thousands of cards or even
hundreds of racks use high voltage isolation transformers and/or fiber optic
isolation from station ground entirely. Residences typically have neither
close proximity to AC service ground, not the financial ability to utilize
fiber or other HV isolation, so living with at least one ground loop is a
requirement. This has been reported to cause problems in some zero-volt
ground reference computing equipment, and isolated grounding is authorized
under certain conditions for that case only. I have not seen comments about
radio frequency interference from ground loop(s) caused by lightning
protection design. If they occur, perhaps they are easily choked with
standard RF control devices. I use those extensively anyway, so maybe that
chokes any ground loop problem, if one ever existed.

Thanks for your comments as always,

Jack

On Mon, 25 Oct 2004 16:46:19 GMT, Irv Finkleman
wrote:
Just wondeing -- is the spring salt water? :-)

The neighborhood use to be orchard. I haven't tasted the water, but I
bet it is fresh water. Remember now, we are speaking about Rain City
- Seattle (although we do have an extensive view of Puget Sound which
is only several blocks, downhill, away).

As I can easily see the water line 6 feet below grade (through the
well shaft), I've no doubt of what may follow if I were to puncture
this raft.

73's
Richard Clark, KB7QHC