Richard Clark wrote in message . ..
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:

Richard, my earlier posts described the grounding my friend, here is quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower where
it enters a buried pvc conduit that travels 150' to house, then up to second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball lightning
inside room fried test cords connected to nothing, hanging on test bench,
where the leads touched tile floor, huge blow-out of tile. AC power blew
wall warts across room, computers next to each other had .22 rifle bullet
sized hole between them. Equipment in this bldg was grounded, and some that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there was a
lot missing from a good ground picture here also.

Jack

Hi Jack,

You know, it sounds like the lightning hit your house/out-building and
went toward the tower.

73's
Richard Clark, KB7QHC

Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did,
it also hit the houses at the same time. You don't get dime size holes
in the house, unless the strike is traveling in the house. I don't
think it's too likely ground currents traveled up the unconnected coax
to the house. It would have gone on to ground at the tower, being it's
well grounded. I think the upstairs part of the house was struck, and
the coax from the drake, along with power wiring was the return to
ground. Note all the damage in the house. Jack, you are one lucky $#^
*#^*@.... It could have burned the house down. The coax to ground
level from the upstairs drake may have routed a good bit of the strike
out to ground. Not enough to save damage though..MK

On Sun, 25 Jan 2004 15:03:59 +0100, "Thierry" To answer me in private
use http://www.astrosurf.com/lombry/post.htm wrote:

Hi,

Was your house/shack stroken by Thor's hammer, I mean a lightning recently ?
I am interested in your experience...

The " system" gets hit about 3 times a year on average.
http://www.rogerhalstead.com/ham_files/tower.htm

If your installaiton was damaged by a strike event, I would like to now if :

Rarely does the system suffer damage.

- you used a central ground point bonded to an external grounding system, as
well as the home ground.

The system uses a network, or grid of ground rods. 31 in the antenna
and radio system, plus 5 for the house electrical system. It's all
bonded together.

- you left some gears switched on during the strike event

Gears as in aircrafts ...
Queens English Vs US English = Gear and aircraft:-)) Over here
neither uses an s which is confusing to some.

- you left the TX switched on and the coaxial plugged without protection

Rarely is the gear disconnected and I don't remember the last time I
disconnected a coax due to storms.

- you installed or not lightning controllers in your electric distribution

I do not have any in the distribution panel.
I do have PolyPhasers for each coax mounted on a common bulkhead which
is tied to the ground system using bare #2 copper cable.

panel
- you had installed another protection
- you swicthed off and unplugged all devices

Never bother.

- you think that the energy came back via the grounding network (probably
dut to a difference of potential in a device)

I lost one computer due to a pulse coming in on the telephone line.
Nothing spectacular.

Tell me only in a few words what was the most probable cause of the
accident.

The one telephone cable was hot to ground with enough voltage to fry
the solid state components.


At last, if you master the subject, do you really think that a grounding
system, as best it could be as the advice provided by PolyPhaser for
example, will never protect you against a direct strike on your antenna or
on the house lightning conductor

I have 31 ground rods in the radio station ground system tied (cad
welded) to over 600 feet of bare copper cable within 2 inches of the
surface.

All antennas are grounded either due to design, or a balun.

The devices appear to work as advertised.

Why ?

I've lost one PolyPhaser with no damage to the rig that was hooked to
it. (Kenwood TM-V7A)

I had one lightening strike destroy a repeater antenna, blow out a
section of 5/8ths inch Heliax about 30 feet down from the antenna, as
well as blow off every bit of water proofing and all the silver
plating from every coax connector at the top of the tower. The only
damage was the input transistor in a two meter rig which was not the
rig connected to the antenna that was hit. That rig was not protected
by a PolyPhaser.

Lightening and the results of a strike are unpredictable, but with the
repeated strikes here, experience has shown me that apparently the
PolyPhasers do their job in a well designed system.

Last Summer I had a barrel connector (N type) short out in the coax
from one of the 75 meter slopers to the tower mounted antenna
selector. I'm assuming it was probably a near by strike, but I have no
way of knowing for sure.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

All this will help me to conclude the article dealing with this matter :
http://www.astrosurf.com/lombry/qsl-...protection.htm

Thanks in advance

NB. Answer preferably through these forums to please everybody.

Thierry
ON4SKY

Roger Halstead wrote:
The " system" gets hit about 3 times a year on average.
http://www.rogerhalstead.com/ham_files/tower.htm

Interesting site. However the links to your larger pictures are all broken.
They refer to files on your local PC eg:
file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm

--
73 Laurie - G6ISY

On Wed, 28 Jan 2004 19:48:06 -0000, "Laurie"
wrote:

Roger Halstead wrote:
The " system" gets hit about 3 times a year on average.
http://www.rogerhalstead.com/ham_files/tower.htm

Interesting site. However the links to your larger pictures are all broken.
They refer to files on your local PC eg:
file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm

Thanks for telling me.

I uploaded some frames for the local EAA Chapter and apparently "Front
Page" in its infuriating propensity to change everything to it's way
of thinking "did it to me" again.

FP is great to work with "at times", but it uses sloppy and bloated
code you don't need. And... If you forget it'll upload files other
than what you planned. Down load 'em and then re upload them and you
will find them reconfigured.

sigh Back to fixing links. (I wonder what else may have been
broken) I have nearly 60 megs on those pages.

Again, thanks,

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Wed, 28 Jan 2004 19:48:06 -0000, "Laurie"
wrote:

Roger Halstead wrote:
The " system" gets hit about 3 times a year on average.
http://www.rogerhalstead.com/ham_files/tower.htm

Interesting site. However the links to your larger pictures are all broken.
They refer to files on your local PC eg:
file:///C:/Documents%20and%20Settings/Administrator.ROGER2.000/My%20Documents/My%20Webs/ham_files/tower8.htm

sigh It wasn't as bad as I feared, but not as good as I hoped.:-))

Having a backup, I turned off the FP extensions on the server,
up-loaded the tower.htm file using ftp and then went through it image
by image.
One directory missing, 4 files missing (htms) and one bad link.
and one image. I have no idea as to where it put that image which is
supposed to be in a sub directory one level down from ham_files which
is one level down from the root.

All-in-all, about 20 minutes to fix including the wait for FP to
reconfigure.

That utility can be great for some things and a royal pain for others.

At least the frames still work.
OTOH when I get the interactive *stuff* going I won't be able to turn
them off.

Again, thanks for letting me know about the broken links.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger Halstead wrote:
sigh It wasn't as bad as I feared, but not as good as I hoped.:-))
[snip]

All-in-all, about 20 minutes to fix including the wait for FP to
reconfigure.
That utility can be great for some things and a royal pain for others.


I've got the same FP 't-shirt' :-)


Again, thanks for letting me know about the broken links.


You're welcome, all seems fine now.
You have a much better head for heights than I have.

--
73 Laurie - G6ISY

Thanks to all responding. A 20m antenna on top of the tower was demolished,
pieces landing 100' away. That one single feedline was connected and
operating a wx-alert system in the shop. The house suffered zero structural
damage, the roofline and 2 antennas on it was definitely not the source of
any of the strikes. The outbuildings also suffered no structural damage or
even marks. The coax(s) most definitely carried the lightning, now whether
they got it from the ground current, tower, tower ground radials, that's
anybody's guess. Coming into the shop, that was likely from the 20 meter
feedline, but the explosion inside the shop right next to my friend was just
"energy", the same kind that blew up floor tile from a patch cord hanging on
a hook by itself. The computers destroyed were from energy in the AC wiring
and cable modem network.

From all I have read here, this hit was (luckily) one of rare intensity and
diversity. Two strikes to the tower later in the summer of last year had
only minor impact on anything.

Jack


"Mark Keith" wrote
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:

Richard, my earlier posts described the grounding my friend, here is
quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods,
etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower
where
it enters a buried pvc conduit that travels 150' to house, then up to
second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball
lightning
inside room fried test cords connected to nothing, hanging on test
bench,
where the leads touched tile floor, huge blow-out of tile. AC power
blew
wall warts across room, computers next to each other had .22 rifle
bullet
sized hole between them. Equipment in this bldg was grounded, and some
that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there
was a
lot missing from a good ground picture here also.

Jack

Hi Jack,

You know, it sounds like the lightning hit your house/out-building and
went toward the tower.

73's
Richard Clark, KB7QHC

Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did,
it also hit the houses at the same time. You don't get dime size holes
in the house, unless the strike is traveling in the house. I don't
think it's too likely ground currents traveled up the unconnected coax
to the house. It would have gone on to ground at the tower, being it's
well grounded. I think the upstairs part of the house was struck, and
the coax from the drake, along with power wiring was the return to
ground. Note all the damage in the house. Jack, you are one lucky $#^
*#^*@.... It could have burned the house down. The coax to ground
level from the upstairs drake may have routed a good bit of the strike
out to ground. Not enough to save damage though..MK

"Roger Halstead"
Rarely does the system suffer damage.

...one computer...
...one PolyPhaser...
...a repeater antenna...
...a section of 5/8ths inch Heliax...
...every bit of water proofing...
...all the silver plating...
...a two meter rig...
...a barrel connector (N type)...

Geesus H. !

I guess so long as you think that you're happy,
then you're happy. ;-)

Carry on then.

Working as a broadcast engineer at a MW (1390 kHz) station quite a few
decades ago, I have placed myself in the transmitter room so as to be
able to look at the towers as a Summer storm passed. That transmitter
did not have an automatic restore circuit. Well, I served as same.
When I saw the lighting strike the towers, I would reset the breaker.
The tubes (813s as I remember) would take that kind of abuse. My
reflexes were good enough in those days that the listeners hardly knew
anything happened.
That is another trade that has disappeared.
Richard knows! Have him tell about the cooked beasties across the
current shunts.
73 Mac N8TT

--
J. Mc Laughlin - Michigan USA

"Richard Harrison" wrote in message
news:25140-40159FDA-

snip

I seem to be very lucky to never have damage with so many
opportunities
for damage. We never lost a transistor radio front end with countless
strikes as evidenced by the pitted antennas. We know the coax arcs in
broadcast stations. Most stations have automatic circuits to kill the
transmitter when the coax arcs.


In medium wave broadcast stations there is almost always a Faraday
screen to keep down the harmonic radiation. It gets countless zaps as
evidenced by pock marks and metal splattered about its shield box.Even
so, the coax gets arcs. When you are on the air, transmitter energy
keeps the arc alive once a transient has struck the arc. Most
transmitters are equipped with a momentary kill relay whose d-c coil
circuit is completed by the coax arc. As soon as the transmitter is
killed, the relay is de-energized and the transmitter returns to the
air.

In the 2-way radio world, the transmitter is going to drop out in a
moment when the mike button is released, or the station was in the
receive mode when the lightning hit and there is no energy to sustain
the arc.

The arc prevents conveyance of the energy to the radio. I never saw a
broadcast transmitter with evidence of lightning inside the
transmitter
and we have a good ides that these stations get struck almost every
time
a dark cloud passes by.

Best regards, Richard Harrison, KB5WZI

"Jack Painter" wrote in message news:LRySb.3240$gl2.2307@lakeread05...
Thanks to all responding. A 20m antenna on top of the tower was demolished,
pieces landing 100' away. That one single feedline was connected and
operating a wx-alert system in the shop.

Big omission... I now think the tower was hit, and piped the energy to
the wx-alert system which then routed it to the rest of the house via
the power wiring. Was that coax routed down to and snubbed to ground
at the base of the tower? From the damage, it almost sounds like it
was elevated in the air from the tower to the shop.

The house suffered zero structural
damage, the roofline and 2 antennas on it was definitely not the source of
any of the strikes. The outbuildings also suffered no structural damage or
even marks. The coax(s) most definitely carried the lightning, now whether
they got it from the ground current, tower, tower ground radials, that's
anybody's guess. Coming into the shop, that was likely from the 20 meter
feedline, but the explosion inside the shop right next to my friend was just
"energy", the same kind that blew up floor tile from a patch cord hanging on
a hook by itself. The computers destroyed were from energy in the AC wiring
and cable modem network.

I bet the wx-alert box was the point where it got into the ac wiring.
I just can't see lightning energy traveling towards the house on a
coax that is on the ground. Once the lightning is at ground, normally
it should stay there. It's where it wants to go. I don't see it
ignoring the ground and radials at the tower, and preferring to go
towards the house on the coax, if the coax wasn't even connected close
to the tower. "I assume it was unhooked, and just laying on the
ground."

From all I have read here, this hit was (luckily) one of rare intensity and
diversity. Two strikes to the tower later in the summer of last year had
only minor impact on anything.

I wouldn't leave any more unprotected feedlines hooked up during
storms. I think all would have been ok, if not for that. Or at least
assuming there was no strike on the power lines a short distance from
your house when this happened. MK