[TowerTalk] Fwd: Fwd: Near Field Lightning Damage

[Roger (K8RI) on TT]

An EMP, is a magnetic pulse of high intensity, but of little duration.  
With semiconductors, it's the voltage generated by the magnetic pulse 
tat causes the semiconductors to fail.  Semiconductor junctions are 
frail, or fragile if you will.  Just handling them can cause elaborate 
junctions to fail without the user feeling a thing.

I worked in the Semiconductor industry for over 26 years, then earned a 
Bachelors degree in CS, started on my masters, when a good job put me 
back to earning a decent wage although as a GA in CS I had a higher pay 
than many out in the work force.   Then worked with computers for 
another 7 years and retired as a Computer Systems project manager.

We often had computers near ultra strong magnetic fields which did not 
bother the computers although I can't say the same for the Hard Drives.

I wasn't there, but based on my background, I can see an EMP causing the 
failure of circuits without the user even being aware.  OTOH in the 
cases sited,  it was most likely induced voltage causing sensitive 
devices to fail.  EMPs are a very complex phenomena

Lightening EMP: https://en.wikipedia.org/wiki/Electromagnetic_pulse

The initial pulse would cause relatively high voltages with each 
successive cycle causing less.
https://en.wikipedia.org/wiki/Electromagnetic_pulseAgain the pulse can 
generate extremely high voltages that can reach 50,000 volts per meter, 
but over a short range unlike the nuclear generated EMP.

I believe lightening can generate a more localized EMP in the E2 class 
more powerful than a nuclear device...discounting the possibility of 
devices that can produce super EMTs.

73

Roger (K8RI)


On 4/21/2015 11:11 PM, Hans Hammarquist via TowerTalk wrote:
> Patrick,
>
>
> You must be a lucky guy or be living in a no or low lightning zone. I can't count the number of CB radios my friends (I never owned a CB radio for some reason) had to repair/replace due to indirect lightning strikes and in a few cases direct hit on the CB antennas. I also have a few SWR bridges where the reflect diode burnt out from lightning induced power.
>
>
> Hans - N2JFS
>
>
> -----Original Message-----
> From: Patrick Greenlee <patrick_g at windstream.net>
> To: towertalk <towertalk at contesting.com>
> Sent: Sun, Apr 19, 2015 10:15 pm
> Subject: Re: [TowerTalk] Fwd:  Near Field Lightning Damage
>
>
> Bill, in so doing you would be just as wrong as Hans.  Re the CB
> comment.  To
> my knowledge we never replaced a CB for lighting causes.
>
> Patrick   NJ5G
>
> On
> 4/19/2015 7:33 PM, Bill Aycock wrote:
>> Hans is right, if a little too gentle.
> I would have called the tale
>> "manufactured" on "Invented" rather than
> "Anecdotal".
>> Bill--W4BSG
>>
>
>   
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-- 

73

Roger (K8RI)


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