"Dave" wrote
...
On Oct 22, 8:40 am, "Szczepan Bialek" wrote:

...
On Oct 21, 2:49 am, "Szczepan Bialek" wrote:



1. If "The intention is to PREVENT a direct lightning strike," - many
sharp
needle is used,
Good luck.

2. If the intention is to CATCH a direct lightning strike and conduct a
strike to ground - a polished big ball is used.
S*
Good luck.

The above apply to grounded tower.

For:
" But, is there a difference in strike rate between grounded and
ungrounded towers of the same height. I would think that the difference
would be very small, and smaller as the height gets bigger."
You wrote: "I'd rather have a grounded mast struck every 5 years with no
damage,
vs an ungrounded mast struck every 10 years that led to heavy
damage or even burned the house down.
So worrying about that is kind of silly I think, when you know
an ungrounded mast is big trouble if it ever does get hit."

The grounded tower catch the electrons in form of "electron conveyer
belt"
and lightning. If the "belt" is efective enough no lightnings. All local
excess of electrons from the cloud flow without lightning. If no, the
lightning appears but it is weak (the sum of electrons is the same).

The strike in the ungrouded tower is always strong.
So You are right.
S*

no, that is not right. a grounded tower can not dissipate enough
charge to reduce the stroke intensity. towers actually attract MORE
high current strokes than the surrounding ground.

Grounded towers with the many spikes dissipate more charge then the simmilar
towers with the polished big ball.
That with the many spikes PREVENT (or minimalise), that with the balls CATCH
(high current strokes).

In article ,
"Szczepan Bialek" wrote:

"Dave" wrote
...
On Oct 22, 8:40 am, "Szczepan Bialek" wrote:

.
..
On Oct 21, 2:49 am, "Szczepan Bialek" wrote:



1. If "The intention is to PREVENT a direct lightning strike," - many
sharp
needle is used,
Good luck.

2. If the intention is to CATCH a direct lightning strike and conduct a
strike to ground - a polished big ball is used.
S*
Good luck.

The above apply to grounded tower.

For:
" But, is there a difference in strike rate between grounded and
ungrounded towers of the same height. I would think that the difference
would be very small, and smaller as the height gets bigger."
You wrote: "I'd rather have a grounded mast struck every 5 years with no
damage,
vs an ungrounded mast struck every 10 years that led to heavy
damage or even burned the house down.
So worrying about that is kind of silly I think, when you know
an ungrounded mast is big trouble if it ever does get hit."

The grounded tower catch the electrons in form of "electron conveyer
belt"
and lightning. If the "belt" is efective enough no lightnings. All local
excess of electrons from the cloud flow without lightning. If no, the
lightning appears but it is weak (the sum of electrons is the same).

The strike in the ungrouded tower is always strong.
So You are right.
S*

no, that is not right. a grounded tower can not dissipate enough
charge to reduce the stroke intensity. towers actually attract MORE
high current strokes than the surrounding ground.

Grounded towers with the many spikes dissipate more charge then the simmilar
towers with the polished big ball.
That with the many spikes PREVENT (or minimalise), that with the balls CATCH
(high current strokes).

Much of this is speculation.

With 10 million volts; currents of 10,000 amperes and strokes that can
travel 30 miles: whether you have a ball or a spike on top of a roof
isn't going to make much difference.

It has been shown that a properly installed lightning rod system; and UL
rated materials connected to low resistance grounds will increase the
odds of protecting lives and property substantially.

(The TV stations on top the Sears tower in Chicago continue to transmit
even as they are being struck.)

wrote
...
In article ,
"Szczepan Bialek" wrote:


Grounded towers with the many spikes dissipate more charge then the
simmilar
towers with the polished big ball.
That with the many spikes PREVENT (or minimalise), that with the balls
CATCH
(high current strokes).

Much of this is speculation.

It is a history: "In the early days of lightning conductors, I believe that
the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.
--
Ian"

With 10 million volts; currents of 10,000 amperes and strokes that can
travel 30 miles: whether you have a ball or a spike on top of a roof
isn't going to make much difference.

The volts appear when no chance to dissipation. To have it on the roof must
be multiplicity of spikes (not one).

It has been shown that a properly installed lightning rod system; and UL
rated materials connected to low resistance grounds will increase the
odds of protecting lives and property substantially.

(The TV stations on top the Sears tower in Chicago continue to transmit
even as they are being struck.)

All is true. I only wanted to add something about the spikes and balls. It
was nice that Ian support me with the funny anecdote.
S*

Szczepan Bia³ek wrote:
It is a history: "In the early days of lightning conductors, I believe that
the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.

I assume a certain biased reporting of anecdotal evidence.:-)

A ball at the top hat of a Tesla coil allows a greater
amplitude of voltage to build up before arcing than does
a point at the top. Therefo

Points should result in more lightning strikes at lower
voltages.

Balls should result in fewer lightning strikes at lower
voltages.

Can't think of any valid reason why either design
should be able to avoid the really big one.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

In message , Cecil Moore
writes
Szczepan Bia³ek wrote:
It is a history: "In the early days of lightning conductors, I
believe that the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.

I assume a certain biased reporting of anecdotal evidence.:-)

A ball at the top hat of a Tesla coil allows a greater
amplitude of voltage to build up before arcing than does
a point at the top. Therefo

Points should result in more lightning strikes at lower
voltages.

Balls should result in fewer lightning strikes at lower
voltages.

Did you mean 'higher'?

Can't think of any valid reason why either design
should be able to avoid the really big one.

Surely, when lightning is about, points allow an essentially continuous
discharge at a low current, while balls allow the voltage to build up
and up, until there is a big 'splat'?
--
Ian

Ian Jackson wrote:
Cecil Moore writes
Balls should result in fewer lightning strikes at lower
voltages.

Did you mean 'higher'?

Two people separated by a common language? :-)

Allow me to rephrase: When the voltages are low,
the ball will tend to discourage the lightning
strikes because the voltage may be too low to
achieve the ionizing threshold potential
surrounding the ball.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

On Oct 23, 2:48*pm, Ian Jackson
wrote:
In message , Cecil Moore
writes

Szczepan Bia³ek wrote:
It is a history: "In the early days of lightning conductors, I
believe that the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.

I assume a certain biased reporting of anecdotal evidence.:-)

A ball at the top hat of a Tesla coil allows a greater
amplitude of voltage to build up before arcing than does
a point at the top. Therefo

Points should result in more lightning strikes at lower
voltages.

Balls should result in fewer lightning strikes at lower
voltages.

Did you mean 'higher'?

Can't think of any valid reason why either design
should be able to avoid the really big one.

Surely, when lightning is about, points allow an essentially continuous
discharge at a low current, while balls allow the voltage to build up
and up, until there is a big 'splat'?
--
Ian

In the end, that's about the way I see it, but I consider
any discharge by either to really be fairly irrelevant.
Trying to avoid strikes by discharge is like whizzing in
a whirlwind. :/
The sharp point streams much easier than the ball,
so the chances of streaming and connected to a down
leader are much greater than with a ball which will
resists streaming at those same potentials.
If you had a spike next to a ball, I would think the spike
would be struck most of the time. You need a good
streamer going to lure a down leader.
But a ball can still stream if the potential cranks up
high enough, and the resulting strike can often be a
a stout one if it can overcome the poor streaming
of the smooth ball.
Both masts should be well grounded.
It's not an accident that most lightning rods have
a sharp point, the same way as most flag poles
have a round ball on top.
One is designed to stream as well as possible in
order to become a more likely target than what it
protects, and the other is designed to stream poorly
to resist strikes compared to the other better streaming
objects near it.
No streamer, no cloud to ground lightning at that
point on the earth. BTW, I've got pictures of streamers.
You can see them at night, and they bend and point to
the down leader as it approaches the earth.
The first one it can connect to forms the final path to
ground, and I think this is in the last 150 yards or so
if I remember right. The leader traveling in appx 150
yard or so steps through the sky.

wrote
...
On Oct 23, 2:48 pm, Ian Jackson
wrote:
In message , Cecil Moore
writes

Szczepan Bia³ek wrote:
It is a history: "In the early days of lightning conductors, I
believe that the French
didn't like the nasty pointy things which the British had installed.
Instead, they decorated theirs with fancy balls at the top - with
sometimes disastrous results.

I assume a certain biased reporting of anecdotal evidence.:-)

A ball at the top hat of a Tesla coil allows a greater
amplitude of voltage to build up before arcing than does
a point at the top. Therefo

Points should result in more lightning strikes at lower
voltages.

Balls should result in fewer lightning strikes at lower
voltages.

Did you mean 'higher'?

Can't think of any valid reason why either design
should be able to avoid the really big one.

Surely, when lightning is about, points allow an essentially continuous
discharge at a low current, while balls allow the voltage to build up
and up, until there is a big 'splat'?
--
Ian

In the end, that's about the way I see it, but I consider
any discharge by either to really be fairly irrelevant.
Trying to avoid strikes by discharge is like whizzing in
a whirlwind. :/
The sharp point streams much easier than the ball,
so the chances of streaming and connected to a down
leader

No down lider. Excess of electrons is in the stormcloud and they jumps if
the difference of voltage exists. At first they jump inside cloud. Next they
jump in the all directions outside cloud. But the all jumps are in form of
oscillations. Lightnings produce LW.

are much greater than with a ball which will
resists streaming at those same potentials.
If you had a spike next to a ball, I would think the spike
would be struck most of the time.

We need here the experimental data. Does anybody know?

You need a good streamer going to lure a down leader.
But a ball can still stream if the potential cranks up
high enough, and the resulting strike can often be a
a stout one if it can overcome the poor streaming
of the smooth ball.

The only cause for spark jump is the voltage difference. Spikes decrease it.

Both masts should be well grounded.
It's not an accident that most lightning rods have
a sharp point, the same way as most flag poles
have a round ball on top.

Is the ball grounded?

One is designed to stream as well as possible in
order to become a more likely target than what it
protects, and the other is designed to stream poorly
to resist strikes compared to the other better streaming
objects near it.

Lightning (electrons) strike the Earth. Grounded ball has the voltage like
the Earth. Nongrounded like the air. Such are neutral. Does not prevent and
not catch. But may be attacked like all.

No streamer, no cloud to ground lightning at that
point on the earth. BTW, I've got pictures of streamers.
You can see them at night, and they bend and point to
the down leader as it approaches the earth.
The first one it can connect to forms the final path to
ground, and I think this is in the last 150 yards or so
if I remember right. The leader traveling in appx 150
yard or so steps through the sky.

The oscilations start from very short in all directions and the last steps
are longest.
S*