[SADXA] Tucson NWS Lightning Forcast -- Sat Jan. 14th, 11am to 10pm

[W7EXG (Bill)]

Along these same lines, I once had a 36 ft, KLM 6 ele 15m Monobander at
about 40 feet. All the parasitic elements on the KLMs were insulated from
the boom. The Boom to Element minimum Spacing was approximately 1/2 inch
(1.27cm)

If I were outside when distant lightning occurred, I would hear/see
electrical arcing from the isolated 20 foot parasitic elements to the
grounded boom, long before I heard the associated thunder. This was scary to
observe. It was a subtle hint for me to get inside. 

Voltage to Arc across a 0.5 inch gap (1.27cm) is: [www.kronjaeger.com]
	Between 2.5 cm spheres = 40kV
	Point to Point Needles = 12kV

This 20 ft element voltage was strictly induced by the distant
Electromagnetic Wave of the lightning strike.

If I were hanging on to an elevated 20ft "rod", with my feet on the ground
during a lightning storm, I would most likely experience from 12kV to 30kV
of voltage on the "rod". The type of "ground" might matter to me.  

Of course common sense would tell us not to do such a stupid thing!! 

That's why when we hear or see Lightning, we all disconnect our antennas, by
possibly hanging onto this 40 to 80 foot "rod" in the process. 

In Summary, I believe it is possible to experience lightning shock, without
a direct hit on your antenna. 

I have worried about this possibility, when disconnecting, based on my past
experience with the KLM. 

Jerry W6XI is stating that not only is it possible, but it happens.
Fortunately, Jerry is still standing to tell us about it. 

It may be possible to engineer a disconnect, so we are not at risk.  Not
sure how many of us have considered, or done this? 

73s, 

Bill W7EXG 

-----Original Message-----
From: SADXA [mailto:sadxa-bounces at mailman.qth.net] On Behalf Of Jerry
Sent: Sunday, January 15, 2017 6:33 AM
To: Southern AZ DX Association E-Mail Reflector
Subject: Re: [SADXA] Tucson NWS Lightning Forcast -- Sat Jan. 14th, 11am to
10pm

Through the years I have had to go out and disconnect antennas when a 
storm approached and I actually took a shock in the process with having 
disconnected  the antenna but still holding it in my hand when a strike, 
perhaps three miles away, occurred.

That always goes  through my mind when messing with the antennas.

W6XI


On 1/14/2017 9:47 PM, Wes Stewart wrote:
> I was on my computer thinking of getting back to the rig when I heard 
> the first "bolt out of the blue (grey)".
>
> I ran outside to disconnect the coax cables and heard another (close) 
> one and was immediately drenched before I got back under shelter.
>
>  On 1/14/2017 9:16 PM, W7EXG (Bill) wrote:
>> Using Lightning Maps, I detected 9 strikes in about an hour ending 
>> 0330Z in
>> the Tucson Area on 1/14/17.
>>
>> My AcuRite Lighting detector detected most of these strikes.
>>
>> One strike detected by Acurite was about 6 Mi NW of Oracle Junction, 
>> about
>> 30 mi from my QTH. I did not hear Thunder for most of the strikes 
>> detected
>> with the MAP or my detector.
>>
>> Was interesting to hear/see the Acurite Detection alert, then see the
>> location of the lightning strike on the Lightning map a few seconds 
>> later.
>>
>> I commend Tucson's NWS for correctly forecasting a "Slight Chance" of
>> Lightning for today. This was a nice warning -- issued yesterday. 
>> Apparently
>> "Slight Chance" should not be ignored.
>>
>> Lightning In January.. How About THAT! Guess lightning is possible 
>> for any
>> month of the year in Tucson.
>>
>> 73s,
>>
>> Bill W7EXG
>>
>
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