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