[Elecraft] K3/100 -Second floor- no RF ground ??

[Steve Ellington]

Don:

You answered my question when you said:

"In fact, I would think that an antenna that has higher resistance to
lightning surge is better - the strength of the surge will be reduced by
the time it reaches the shack. "

I have never seen this issue addressed.

So bottom line:
Using stranded wire for antennas improves ligtning protection.

Steve
N4LQ
----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at embarqmail.com>
To: "Steve Ellington" <n4lq at carolina.rr.com>
Cc: <don at w3fpr.com>; <n1al at cds1.net>; <elecraft at mailman.qth.net>
Sent: Thursday, February 25, 2010 12:13 AM
Subject: Re: [Elecraft] K3/100 -Second floor- no RF ground ??


> Steve,
>
> That is a bit of a strange question - because I never though of my
> antenna wires as being a conductor for lightning.  While the antenna
> wires will pick up lightning surges, I don't think that is what is being
> considered.  What they are talking about is how to dissipate whatever
> lightning surge that makes it into the shack to ground.  For that - yes,
> you would use solid conductor (of heavy guage) wire, or better yet flat
> copper strap with its large surface area for the station safety
> ground.   Conduct the energy out of the shack and into the earth ground
> where it can dissipate.  The greater earth surface that you can
> distribute that energy, the better - be that several connected ground
> rods separated by twice their length or a system of buried conductors
> like a perimeter wire around the building where the shack is housed.
>
> In fact, I would think that an antenna that has higher resistance to
> lightning surge is better - the strength of the surge will be reduced by
> the time it reaches the shack.  The path from the shack to your
> lightning protection ground is a different matter, and should be low
> impedance at all frequencies if that is possible - it is not, so we do
> the best we can with conductors having greater surface area and plenty
> of conducting capability for high currents as well.
>
> So stranded wire is OK for antennas, but not for the run from the
> station to the safety ground.
>
> 73,
> Don W3FPR
>
> Steve Ellington wrote:
>> Speaking of lightning grounds. MFJ says use soild wire or flat copper for
>> ground wire and never use stranded or braided wire. They claim the latter
>> has high impedance to lightning.
>> Ok, fine....so if my antenna is stranded wire, does it have high 
>> impedance
>> to lighting? Would it be less safe to make ones antenna from solid
>> conductors? Yes...a weird question but it's been bugging me.
>> Steve
>> N4LQ
>>
>>


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