[time-nuts] Thunderbolt cabling questions

[Rix Seacord]

Hi gang
Just to upset the apple cart a bit, high trees do not necessarily 
protect a large area from lightning.
In my past life as a range officer at a large shooting facility, we were 
hit by lightning directly in front of the firing line during a storm. 
The tree line was about 20 to 30 ft behind us and at least 50+ feet higher.
There was even evidence of arcing between 2 pieces of conduit stuck in 
the ground about 5 ft apart. first and last time I saw a fire ball.
For induced charges from nearby strikes nothing beats a good ground and 
lightning protector system.
If a direct hit, I hope your insurance is paid up.
My gps antennas are about 25 above ground just above my roof line. The 
mast is grounded to 2 ground rods and the coax fed through gas tube 
lightning protects. No problems even with hits several hundred yards away.

Ewing (Rix) Seacord
K2AVP/4/499
eseacord at verizon.net

845-628-0892 Home
914-262-9186 Cell
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On 6/12/2012 1:31 AM, Hal Murray wrote:
> albertson.chris at gmail.com said:
>> But you know what?  If you simply place an automotive "puck" type GPS
>> antenna on your roof you have to do the same thing.  It must be grounded the
>> same way, same lightening protection and so on.   So in the end you may as
>> well put up a professional looking and permanent  steel mast.  It is not
>> that much more work.
> What about putting a skylight high on the roof and putting the antenna up in
> it?
>
> What's magic about inside vs outside the roof/skylight envelope?
>
> -----------
>
> I have a large pine tree out front.  It's roughly 3x the height of my (one
> story) house.  What are the chances of any lightning hitting my house rather
> than the tree?  What if I put an antenna on the top of my house so the tree
> is only 2x the height of my antenna?
>
> Of course, that depends on how far the tree is from my house.  Not far.  Call
> it 45 degrees from the back of my house to the top of the tree.  An antenna
> on the top of my house would probably be below that sight line.
>
> Is there a good book or URL on lightning vs antennas?  Again, I'm interested
> in both the technical issues as well as the local zoning/legal issues.
>
>
>