[Icom] Strike

Thu May 6 14:07:34 EDT 2004

I live in Arlington (spitting distance to Dallas) and had a small feeder strike a couple of months ago.
I lost an antenna and several radios, automatic antenna tuner, power supply, satellite receiver, oven, dsl modem etc.

Items were lost through the ground both AC and RF/power supply/battery connections.

The items not lost were not connected to anything or had no ac ground connection.

My future strategy is to fully disconnect everything from everything and only run those items required on battery backup as well as use indoor antennas where feasible.

My pc runs on a small ups, the monitor runs on a small ups, the dsl modem/router-switch runs on it's own small ups.  Those probably saved those items except for the dsl modem....probably got hit through the phone line.

I lost a 6m allmode rig that was attached to the same battery source as a dual band kenwood that was still attached to rf ground.  The kenwood might not be repairable, the 6m powers up but does not receive or transmit.  It may be the transistor that operates the relay at the antenna connection between the recevie and transmit sections.  Still trying to locate a service manual for the ft-690rII.

I feel I got lucky because it was not a direct strike and I didn't lose everything.  I also learned a lot above and beyond what I have read here and on other groups as well as professional grounding texts.

My thoughts are this....
It is not if you will be struck, but rather a matter of when since we tend to put lightning rods up in the air.

73,
Jon
KD5SFA

-----Original Message-----
From: [email protected]
Sent: May 6, 2004 7:35 AM
To: [email protected]
Subject: Re: [Icom] Strike

Hi Joe-

This may sound like complete blasphemy but I have had several very
knowledgeable people tell me I should not ground my single radio at all. It
is by necessity on a second floor. What are your thoughts or anyone else in
the group?

I do disconnect from the antenna when not operating. Should I also
disconnect the radio from the house AC line? I do disconnect my 4KL linear
when not operating. I live in Texas and we get a fair amount of lighting
although I have never heard of a ham strike in Dallas although I'm sure
several must have happened.

 I use a DSL line for spots so the 756 Pro II radio and the linear are
indirectly coupled to the telephone line through a laptop serial port line.
Should that laptop line be disconnected when not operating?

Thanks, Andy K5VM

----- Original Message ----- 
From: "Joe" <[email protected]>
To: <[email protected]>
Sent: Thursday, May 06, 2004 5:06 AM
Subject: Re: [Icom] Strike

| It could very well be that the strike went OUT the telephone line and not
in. The strike may have come in the power line and looked for multiple
ground paths.
|
| I work for a cellular provider and we have experienced many lightning hits
in the past.  Most damaging hits come in the power lines.  Suprisingly, the
tower hits are not as damaging as the power line hits.  Tower hits sometime
cause no damage at all (I've been at the site during a couple of these).
The power line is usually the culpret of most of the worse damage, and it is
capable of handling tremendous surge currents before the breakers trip.
|
| The telephone line really does not have the current carrying capability of
massive damage.  It sounds like the strike came in the power line and found
multiple grounds through your equipment and the telephone line.
|
| The trick to having a good ground system is to ground things so that most
of the strike goes directly to ground and not through your equipment.
Sometimes this is not possible in a ham shack because you cannot provide a
good enough ground to absorb the entire hit.  The strike takes multiple
paths.  Unles you have a near perfect ground and ground ring like a cell
site should have, disconnecting the radios is the only safe way.  Sometimes
people confuse a safety ground (like a 3 prong plug) with a lightning
protection ground.
|
| As far as damage is concerned, a poor lightning protection ground can be
worse than no ground at all .
|
| 73, Joe, k1ike
|
| William Diamond <[email protected]> wrote:
| No need to get a thread started on this but the phone Co. claims that
their
| system is so well protected, they could not induce a strike to the inside
of
| a dwelling. Yea right ...........
|
| There are 4 separate 110 and 2 220 volt lines ran to the radio room and
all
| four of the 110 breakers were tripped.
|
|
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----
Your Moderator: Dick Flanagan K7VC, [email protected]
Icom Users Net: Sundays, 1700Z, 14.316 MHz
Icom FAQ: http://www.qsl.net/icom/