I agree with Tom and Bob that the big, heavy choke is not needed. Even it
offers too much inductance to be an effective lightning path.
A spark gap is the thing to use across the choke or shorted 90 degree
feedline. It should have a weather cover and be set close but not too
close. See ROSS ENGINEERING for a picture of a spark gap. I've use 1/4"
carriage bolts for spark gaps at 1 kA. I would use a larger one for
protection against a direct lightning strike. Only 1% of strikes reach 100
kA but I think that's a good current to design to.
http://www.rossengineeringcorp.com/hv_spark_gap.htm
Dave WX7G
On Thu, Jul 26, 2012 at 7:53 PM, Bob Kupps <n6bk@yahoo.com> wrote:
> Hi Phil
>
> I'm no expert but plan to use a quarter wave shorted stub of RG6 at the
> feed point of my verticals for static drain and harmonic reduction, along
> with a spark gap in the event of a close strike.
>
> 73 Bob
>
> ----- Forwarded Message -----
> From: Phil Clements <philclements@centurylink.net>
> To: topband@contesting.com
> Sent: Friday, July 27, 2012 2:03 AM
> Subject: Topband: Choke Construction Info Needed
>
> I need to construct a heavy-duty choke to be installed from the feed point
> of my 160 meter vertical to ground, for static drain and for lightning
> protection. How large does the wire, form, and inductance need to be?
>
>
>
> Thanks in advance for your expertize!
>
>
>
> (((73)))
>
> Phil, K5PC
>
>
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
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