[BC] Lightning and grounding ... fun for all!

[Alan Alsobrook]

Bruce,
I did read your post on radio tech, I have read the information you have 
provided below. I have also seen the number of strikes dramatically 
decrease when a static dissipation array was installed. So does it work?
I can't say it does or it doesn't, but it sure seems to help. In the 
poly phasor document you have provided, it indicates that a ground for 
the array may not have been provided. What I know of the dissipater 
systems they don't work without a very solid ground. Also if you 
properly install them you will have also provided a way to control a 
strike should it occur. So far none of my clients have decided to 
installed an array, so I've only played with them on others sites.
But I'm not as quick to dismiss their effectiveness since I have seen 
the lack of evidence that they don't work.
One facility I'm thinking of was getting serious damage at least twice a 
year. They installed a system, they haven't received any damage since 
that time (about 5 years now). So the question is are they just lucky, 
or did the array do something to help? Was it the additional grounding 
they did to install the system? I think only Mother nature knows for 
sure and she hasn't written a white paper on it yet.
It seems to me (humm I might have to jump on this) the ideal solution 
might be a Franklin rod incorporated into a dissipating device.

I have experienced up close and personal what I consider the strike of 
the century. It destroyed all conventional protection. Would a 
dissipater have prevented it? we'll never know.  This strike hit 1 tower 
in a 3 tower DA array. It came from an almost clear blue sky, one lonely 
cloud, that produced one single strike and no rain. It hit the beacon 
and demolished it (all glass blown out top blown off, to be later found 
500' from a 300' tower) at the base of the tower 2" solid arm ball gaps 
were bent backward around the base of the tower. 4 3" .032 copper straps 
feeding to the ground system were gone leaving only black stripes on the 
base where they had been. With ground gone the strike decided it would 
run the cables back to the transmitter shack some 1500' away. Once in 
the phasor it open arced 22' across the room to a 100 pr phone entry 
block. were it exited the building to run under the street and blow a 
5000 pr phone cable in half under the street. I was in the room but 
luckily not between the phasor and phone block when the strike hit. It 
was a few minutes before I could see again and my ears rang for 2 days.
there was quite a bit of other damage at the site. Radio station damages 
were about $25,000, and probably about $10,000 for ma Bell.  I'm not 
sure how much it costs to have 10 cable splcers working around the clock 
for 2 days. Ok so this story doesn't provide anything towards the 
discussion at hand, other than good conventional systems can fail too. 
But I do like telling this story. :)


Brucee Doerle wrote:
> Alan, Why waste the money?  Why have false expectations?  Enclosed is
> a technical brief by Polyphaser, a well respected company in this
> field and within the RF industry.  They answer some of your questions
> and reference situations that clearly define the value of these
> devices.  Testimonials from the unknowing is NOT proof but snake oil
> salesmanship.  In the lengthy email I posted on Radio Tech net on
> January 17th "Lightning abatement", I discussed other proof that CTS
> devices do not work.  You need to read the material before your
> question proof versus testimonials. Bruce

-- 
Alan Alsobrook CSRE AMD CBNT
St. Augustine Fl. 32086 904-829-8885
aalso at Bellsouth.net