Every year, I fear the spring and summer. I have a random wire antenna
that traverses one side of my property, the wire extending about 70 feet.
No lightning protection. I remove the wire from the radio when I am at home
and I know that I storm is coming. But when I am at work, and storms happen
unexpectedly, the radio stays connected. Even protecting the radio from the
static of a nearby lightning strike by disconnecting it doesn't protect the
house from the results of a strike to the wire.

I would like to switch to a V shaped antenna, perhaps it is what they refer
to as an "inverted V" extending from a central point on my house to both
sides of the property. I would like to feed the antenna with coax, so as to
reduce the likelihood of household interference. The feed would only be
about 20 feet long. I would have trouble grounding it at the apex of the V,
since that would be on the house itself and the patio is directly below it,
providing much cement but little ground to place the rod. Though I could
drill the patio, I am unsure of the pipes below it.

My lot, at least as far as the usable area for the antenna is concerned,
would be about 30 feet wide and 70 feet long, with the elevation of the V
to be approximately 12 feet from the ground.

Can anybody conceptualize an antenna that I can use, with lightning
protection, and provide links to it? Is anybody using something similar?

Thanks for any help.

Dr. Artaud

"§ Dr. Artaud §" wrote:

Every year, I fear the spring and summer. I have a random wire antenna
that traverses one side of my property, the wire extending about 70 feet.
No lightning protection. I remove the wire from the radio when I am at home
and I know that I storm is coming. But when I am at work, and storms happen
unexpectedly, the radio stays connected. Even protecting the radio from the
static of a nearby lightning strike by disconnecting it doesn't protect the
house from the results of a strike to the wire.

I would like to switch to a V shaped antenna, perhaps it is what they refer
to as an "inverted V" extending from a central point on my house to both
sides of the property. I would like to feed the antenna with coax, so as to
reduce the likelihood of household interference. The feed would only be
about 20 feet long. I would have trouble grounding it at the apex of the V,
since that would be on the house itself and the patio is directly below it,
providing much cement but little ground to place the rod. Though I could
drill the patio, I am unsure of the pipes below it.

My lot, at least as far as the usable area for the antenna is concerned,
would be about 30 feet wide and 70 feet long, with the elevation of the V
to be approximately 12 feet from the ground.

Can anybody conceptualize an antenna that I can use, with lightning
protection, and provide links to it? Is anybody using something similar?

An inverted 'V' itself would be vertical... a horizontal 'V' I think is what you
envision.

Lightning protection is itself a science I suppose. Never had a direct hit here,
but did see blue sparklers off a disconnected lead 20 or so years ago.

dxAce
Michigan
USA

Drake R7, R8, R8A and R8B

http://www.iserv.net/~n8kdv/dxpage.htm

Dr Artaud & DX Ace,

The Tips can be Elevated above ground or
the Tips can be at/near ground level and a
Ground Rod placed at both ends (Tips) with
a Lightning Aresster (GDT) mounted on each.
.................................................. .......

The higher the ends above ground, the better.
You have less earth loss. There is no need to
use lightning arresters at the tips of the dipoles
to ground. If the wire were actually close enough
to ground to arc to ground, it will do it, arrester, or
not. Being as you are not protecting any devices at
the ends, there is no real point in using arresters. The
arrester should be in the feedline leading to the radio.
If the inv vee is supported by a tree or mast, the lightning
is more likely to take that path to ground, than the path
of perpendicular antenna wires to ground.
Lightning doesn't like to take sharp turns. So you should
always ground the supporting mast well, if it's metal.
It's gonna take the brunt of the strike to ground...
Horizontal wire antennas are not near as prone to be a
lightning target, as say a vertical, or other tall mast.
IE: a dipole, or inv vee hung in a tree will add little to the
overall likelyhood of that tree being struck.
It would probably be struck anyway, antenna or not,
if lightning was that close, to choose that target. I bet in most
cases, the antenna would basically be untouched, unless the
strike found the feedline running down the tree, and decided to
use it....You can always snub the feedline to ground at the base
of th tree in a case like that. I know I have had two direct strikes
to my mast supported my various dipoles, and have never had
any indication of wire, or coax damage.
That tells me most of the strike is carried to ground
by the mast, which does stick up about a foot above my
antenna apex. "I currently have 160/80/40 dipoles on one
feedline...Appx 440 ft of wire in the air...The apex about 42 ft
high supported by a metal mast. So far, in 35 years of hamming,
SWLing, I've never had a horizontal wire dipole be a lightning
target. But mine are never higher, than surrounding
objects, trees, etc unless supported by a mast, or tree, which
then becomes a more preferred target than the dipole itself...
Not saying it can't happen. It surely can.
But not near as often as vertical targets.
Even at 42 ft, I've still got trees taller than that in the yard...
That helps...The last strike hit the tree in the front yard....
If the vertical target is well above the house, other objects, you
can bet on it taking a zap sooner or later. Most people don't
have wire antennas higher than the surrounding trees, etc,
unless they have a vertical support to support it...When they
get above the surroundings, is when their chance of a strike
goes up sharply. Even horizontal metal can be a problem if
it's really high...IE: beams, etc..MK

wrote in news:1114144805.607357.167380
@g14g2000cwa.googlegroups.com:

Thanks for the response. We just last night had another thunderstorm,
depositing plenty of noise and lightning nearby. Our house is physically
lower than the houses on either side, and the end of our yard has a very
tall Silver Maple tree, to which my random wire antenna runs from the
house. The wire ends about 7 feet from the tree trunk, and is tied to the
tree with the rubber strip that is used to hold screens in windows frames.
I fear that a strike to the tree will impart more than static to the random
wire antenna.

Perhaps you, RHF, Jack Painter, or others can comment on how to protect the
random wire from transferring a lightning strike to the tree from following
the antenna wire. As I sleep by the radio, I don't with to be awakened
writhing from a lightning strike.

Regards,

Dr. Artaud

The higher the ends above ground, the better.
You have less earth loss. There is no need to
use lightning arresters at the tips of the dipoles
to ground. If the wire were actually close enough
to ground to arc to ground, it will do it, arrester, or
not.................

"? Dr. Artaud ?" wrote

Thanks for the response. We just last night had another thunderstorm,
depositing plenty of noise and lightning nearby. Our house is physically
lower than the houses on either side, and the end of our yard has a very
tall Silver Maple tree, to which my random wire antenna runs from the
house. The wire ends about 7 feet from the tree trunk, and is tied to the
tree with the rubber strip that is used to hold screens in windows frames.
I fear that a strike to the tree will impart more than static to the
random
wire antenna.

Perhaps you, RHF, Jack Painter, or others can comment on how to protect
the
random wire from transferring a lightning strike to the tree from
following
the antenna wire. As I sleep by the radio, I don't with to be awakened
writhing from a lightning strike.

Regards,

Dr. Artaud

In my opinion, the best lightning arrestor products for up to 1.5 kw
transmission systems are made by Industrial Communication Engineers (ICE).

Solutions for either open-wire (no coax feed involved) or coaxial feedline
arrestors are shown at Array Solutions, the distributor for I.C.E.

http://www.arraysolutions.com/Products/ice/3.html

ICE also makes very convenient grounding blocks for the custom connections
of coax shield grounding. This allows a "manifold" connection of several
coax shield grounds to a ground rod and works very well. But Andrews and
Harger and others also make those, and Harger is probably the best for
grounding materials in general. Local electrical distributors will carry (or
order) Harger products.

Jack Painter
Virginia Beach, Virginia

"RHF" wrote in news:1113937736.278231.195640
@f14g2000cwb.googlegroups.com:

Thnaks for your comments. Please see my response elsewhere in this thread
concerning grounding needs.

Dr. Artaud

Dr Artaud & DX Ace,
.
The 'classic' Inverted "V" Antenna would usually
have a combined Top Apex Angle of 90* to 120*
or a Bottom Tip Angle of 30* to 45*.

Lightning strikes very often happen on very pretty Summertime
days/nights when you least expect lightning to happen.There are very
good ways to protect your radio antennas and radios agains't lightning
strikes.I don't know much of those ways,perhaps someone who does know
will show up and elaborate about such things.I know this much though,
www.brickwall.com www.pricewheeler.com I own an use a Brickwall
model 8R15.
cuhulin

"§ Dr. Artaud §" wrote
Every year, I fear the spring and summer. I have a random wire antenna
that traverses one side of my property, the wire extending about 70 feet.
No lightning protection. I remove the wire from the radio when I am at
home
and I know that I storm is coming. But when I am at work, and storms
happen
unexpectedly, the radio stays connected. Even protecting the radio from
the
static of a nearby lightning strike by disconnecting it doesn't protect
the
house from the results of a strike to the wire.

I would like to switch to a V shaped antenna, perhaps it is what they
refer
to as an "inverted V" extending from a central point on my house to both
sides of the property. I would like to feed the antenna with coax, so as
to
reduce the likelihood of household interference. The feed would only be
about 20 feet long. I would have trouble grounding it at the apex of the
V,
since that would be on the house itself and the patio is directly below
it,
providing much cement but little ground to place the rod. Though I could
drill the patio, I am unsure of the pipes below it.

My lot, at least as far as the usable area for the antenna is concerned,
would be about 30 feet wide and 70 feet long, with the elevation of the V
to be approximately 12 feet from the ground.

Can anybody conceptualize an antenna that I can use, with lightning
protection, and provide links to it? Is anybody using something similar?

Thanks for any help.

Dr. Artaud

The Inverted-vee is a center (or off-center) fed dipole with it's ends lower
than the feedpoint. Rarely a desired design, it usually results from being
unable to elevate both ends equal to the feedpoint of a half wave dipole. It
nonetheless works fairly well and is a "complete" antenna, requiring no
grounding. It is not a vertical antenna as Ace suggested.

However, for lightning protection, all antenna feedlines regardless of
antenna type should be shield-grounded if using a coax feedline. The first
point of this shield-grounding should be as near as possible to where a
grounding conductor/jumper/bond can be first located. That means on the
tower if the tower is the feedpoint of the inverted-vee, or where the
feedline first reaches earth-grade at 90 degrees from the feedpoint. Coax is
again shield-grounded at the ground rod used as the shack's single point
ground. A surge protector or oft-called lightning arrestor is then used to
protect the equipment where the feedline originates.

If it is physically possible for the antenna to take a direct lightning
strike (not a probability if nearby objects are higher) then the feedpoint
shield ground is the primary discharge point, and should have a network of
ground rods connected by heavy (#4 or larger copper wire or wide copper
straps). Even if a direct strike is not possible, indirect strikes
(flashovers from a nearby tree or other higher object) are still possible,
and the first shield ground remains of primary importance in the protection
scheme. Feedline running along the earth or even buried a few inches in the
earth are also subject to magnetic and capacitive coupling of lightning
strikes nearby. The near surface of earth carries 10's of thousands of volt
potential from strikes as far as 100 yards away. Any ground system that is
connected to equipment in the shack has the potential to reference these
voltages right onto the grounded equipment cases in the shack. This is why
proper bonding of inside equipment and all grounding systems is vital to
prevent this ground potential rise from exiting the equipment through AC
power connections out the rear of the equipment. See my site for further
information about bonding and grounding antennas and equipment:

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

Best regards,

Jack Painter
Virginia Beach, Virginia

Jack Painter wrote:

"§ Dr. Artaud §" wrote
Every year, I fear the spring and summer. I have a random wire antenna
that traverses one side of my property, the wire extending about 70 feet.
No lightning protection. I remove the wire from the radio when I am at
home
and I know that I storm is coming. But when I am at work, and storms
happen
unexpectedly, the radio stays connected. Even protecting the radio from
the
static of a nearby lightning strike by disconnecting it doesn't protect
the
house from the results of a strike to the wire.

I would like to switch to a V shaped antenna, perhaps it is what they
refer
to as an "inverted V" extending from a central point on my house to both
sides of the property. I would like to feed the antenna with coax, so as
to
reduce the likelihood of household interference. The feed would only be
about 20 feet long. I would have trouble grounding it at the apex of the
V,
since that would be on the house itself and the patio is directly below
it,
providing much cement but little ground to place the rod. Though I could
drill the patio, I am unsure of the pipes below it.

My lot, at least as far as the usable area for the antenna is concerned,
would be about 30 feet wide and 70 feet long, with the elevation of the V
to be approximately 12 feet from the ground.

Can anybody conceptualize an antenna that I can use, with lightning
protection, and provide links to it? Is anybody using something similar?

Thanks for any help.

Dr. Artaud

The Inverted-vee is a center (or off-center) fed dipole with it's ends lower
than the feedpoint. Rarely a desired design, it usually results from being
unable to elevate both ends equal to the feedpoint of a half wave dipole. It
nonetheless works fairly well and is a "complete" antenna, requiring no
grounding. It is not a vertical antenna as Ace suggested.

They are generally vertically oriented, therefore the 'inverted vee'
designation.

dxAce
Michigan
USA



However, for lightning protection, all antenna feedlines regardless of
antenna type should be shield-grounded if using a coax feedline. The first
point of this shield-grounding should be as near as possible to where a
grounding conductor/jumper/bond can be first located. That means on the
tower if the tower is the feedpoint of the inverted-vee, or where the
feedline first reaches earth-grade at 90 degrees from the feedpoint. Coax is
again shield-grounded at the ground rod used as the shack's single point
ground. A surge protector or oft-called lightning arrestor is then used to
protect the equipment where the feedline originates.

If it is physically possible for the antenna to take a direct lightning
strike (not a probability if nearby objects are higher) then the feedpoint
shield ground is the primary discharge point, and should have a network of
ground rods connected by heavy (#4 or larger copper wire or wide copper
straps). Even if a direct strike is not possible, indirect strikes
(flashovers from a nearby tree or other higher object) are still possible,
and the first shield ground remains of primary importance in the protection
scheme. Feedline running along the earth or even buried a few inches in the
earth are also subject to magnetic and capacitive coupling of lightning
strikes nearby. The near surface of earth carries 10's of thousands of volt
potential from strikes as far as 100 yards away. Any ground system that is
connected to equipment in the shack has the potential to reference these
voltages right onto the grounded equipment cases in the shack. This is why
proper bonding of inside equipment and all grounding systems is vital to
prevent this ground potential rise from exiting the equipment through AC
power connections out the rear of the equipment. See my site for further
information about bonding and grounding antennas and equipment:

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

Best regards,

Jack Painter
Virginia Beach, Virginia