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 <n...@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 <philcleme...@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