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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