Hi Mike, I have always been taught that the tops of clouds are the positive charges and the bottoms of the clouds are the negative charges and that is what the lightning arc is (the negative charges). That theory seems to be supported by this article:
http://www.physicsclassroom.com/class/estatics/Lesson-4/Lightning
Frank
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]] On Behalf Of Mike Keithley
Sent: Thursday, June 25, 2015 9:40 PM
To: [log in to unmask]
Subject: Re: Lightning strikes, was: Grounding Question
I think the earth is negative and the clouds ares positive. So we have a positive to negative current flow.
----- Original Message -----
From: Frank Ventura <[log in to unmask]>
To: [log in to unmask]
Date: Thursday, June 25, 2015 6:27 pm
Subject: Lightning strikes, was: RE: Grounding Question
>
>
> Are you kidding me? Lets think a minute about what lightning is. It is an =
> electrical arc, in this case between a cloud and the ground. The arc is neg=
> atively charged particles looking for a positive ground, as opposites attra=
> ct. Some lightning strikes contain as much as one billion volts (remember t=
> he first Back to the Future movie?). If that awesome charge is strong enoug=
> h to arc several miles through open air can you imagine how easily it can a=
> rc through a rubber or glass insulator. It is amazing how many people belie=
> ve that the rubber tires of a car keep it from being hit by lightning. Ther=
> e are two basic reasons why cars don't get hit by lightning with the latter=
> being more important, they are:
> a. Cars are relatively low to the ground and are rarely in a position to be=
> the path of least resistance.
> b. Almost all cars have negative ground electrical systems. Remember from a=
> bove that lightning is a negatively charge partical arc looking for a *posi=
> tive* ground to strike. A negatively charged arc is not attracted to a nega=
> tive ground. Rubber tires have nothing to do with it. With all that voltage=
> if lightning did hit the car body it would arc the gap from the body to gr=
> ound below and probably turn the tires into a molten blob of fake rubber in=
> the process. It is the negative ground electrical system that makes the ch=
> arges repell not attract. Now with that said there are a few (mostly Britis=
> h) cars from the period following WWII that actually have positive ground e=
> lectrical systems. Electrically speaking they could attract a negatively ch=
> arged arc but I doubt it has happened much due to the reason given in a abo=
> ve.
> So in short if you merely disconnect the coax from the connector on your ho=
> use and leave it a few inches or even a few feet away from your house you c=
> an seal it in glass, wrap it in rubber or shove it in a ham sandwhich for t=
> hat matter and lightning can still arc from the cable to your humble abode.=
> =20
> Frank
> PS see:
> http://www.google.com/imgres?imgurl=3Dhttp://images.nationalgeographic.com/=
> wpf/media-live/photos/000/002/cache/lightning-over-water_270_600x450.jpg&im=
> grefurl=3Dhttp://environment.nationalgeographic.com/environment/natural-dis=
> asters/lightning-profile/&h=3D450&w=3D600&tbnid=3DzOwdXoP47bq-8M:&zoom=3D1&=
> tbnh=3D160&tbnw=3D213&usg=3D__zkPY7nzoAY6ktc1km2namr1l0No=3D&docid=3D21jTPm=
> qZw7qgRM
>
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]] =
> On Behalf Of Tom Behler
> Sent: Thursday, June 25, 2015 8:52 PM
> To: [log in to unmask]
> Subject: Re: Grounding Question
>
> Jim:
>
> Here's an idea:
>
> To insulate the coax connector, would it be sufficient to put one of those =
> rubber boots around the connector, such as those that you get with new runs=
> of coax?
>
> I would think that should be a pretty good insulator.
>
> Tom Behler: KB8TYJ
>
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Jim Shaffer
> Sent: Thursday, June 25, 2015 6:55 PM
> To: [log in to unmask]
> Subject: Re: Grounding Question
>
> Tom I never meant to imply that the virtual ground you have would protect y=
> ou from lightning. Unplugging the antenna is the best way to go as far as =
> I know. In fact, it's almost certainly true that if the antenna, or part o=
> f it, is grounded, that would actually increase your chances of a lightning=
> strike. You should disconnect the antenna, and perhaps put the end of the=
> coax in a glass jar, or some sort of insulator. That's of course no guara=
> ntee, but it might keep a lightning strike on the antenna from starting a f=
> ire in your trailor.
> --
> Jim, ke5al
> -----Original Message-----
> From: Tom Behler
> Sent: Thursday, June 25, 2015 11:32 AM
> To: [log in to unmask]
> Subject: Re: Grounding Question
>
> Well, Jim, this is what I'm confused about, and I sure wish I knew what wou=
> ld be best.
>
> Of course, I guess putting in a ground rod would not hurt anything, but I d=
> on't think I'm going to be able to do that at least for the next few days.
>
> For the past several years, I have used the system I described, with no pro=
> blems.
>
> But, of course, that doesn't guarantee that I won't have any problems in t=
> he future should the lightning god strike.
>
> It's just a difficult call, in my opinion.
>
> Tom Behler: KB8TYJ
>
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Jim Shaffer
> Sent: Thursday, June 25, 2015 12:01 PM
> To: [log in to unmask]
> Subject: Re: Grounding Question
>
> Tom, from what I've read, what seems important is to be grounded to what's =
> around you. It sounds like what you have now is a virtual ground, which is=
> supposedly just fine. I'll bet, if you do put down an 8 foot ground rod, =
> you'll see no difference.
> --
> Jim, ke5al
> -----Original Message-----
> From: Tom Behler
> Sent: Thursday, June 25, 2015 9:01 AM
> To: [log in to unmask]
> Subject: Grounding Question
>
> Hello, all.
>
>
>
> I know I'll get varying opinions on this, but I have a question about stati=
> on grounding out at the RV camp site.
>
>
>
> As many of you know, my main rig out there is my TS480, and I will be using=
> my trusty Alpha Delta DXCC multi-band dipole. When all is said and done, =
> I'm hoping the antenna will be up about 30 feet in the trees.
>
>
>
> Just as I did in previous years, I will have a ground connection running fr=
> om the ground screw on the TS480 to a terminal ground connection on the bac=
> k bumper of the RV. I use 10-gauge wire for this connection.
>
>
>
>
>
> Of course, I am very careful about disconnecting my antenna at any sign of =
> thunderstorms.
>
>
>
> Is this adequate, or should I be pursuing something additional?
>
>
>
> I wouldn't think a dipole would have to be grounded with a ground rod such =
> as is the case with a vertical, or a beam antenna on a tower, but my theore=
> tical knowledge in this area is a bit lacking.
>
>
>
> Thanks for any thoughts.
>
>
>
> Tom Behler: KB8TYJ
>
>
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