I took a lightning strike to my shunt fed tower crank up earlier this year. It vaporized the #8 wire that ran from the top to the bottom of the tower. Some of the radials turned into fuses. Interestingly, not at the base of the tower, but 50 - 60 ft from the base.
I disconnect all of the feed lines and control cables outside of the shack when not in use. 73 Gregg -----Original Message----- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Guy Olinger K2AV Sent: Saturday, July 28, 2012 01:06 To: N2TK, Tony Cc: topband; donov...@starpower.net Subject: Re: Topband: Spark gaps What is the condition of your 160m radials after the lightning strike? 73, Guy. On Fri, Jul 27, 2012 at 7:48 PM, N2TK, Tony <tony....@verizon.net> wrote: > As a side note, last night when the storm came barreling in with very > strong > winds I was watching the tower as the elements whipped around. Bang! First > time I saw a direct hit on the tower. Had spots in my eyes for a while. > Tower is about 150' from the kitchen window. > > I had everything tuned off but I never disconnect anything. > Was anxious when I turned on things this morning. Everything is fine except > the fuse blew on the Prosistel when I turned it on. Replaced the fuse and > everything is now fine. > I guess my ground system is working. Couldn't find any burn marks anywhere > inside or at the tower. With no visual or electrical damage maybe the tower > has been hit before? > > By the way the tower is grounded and I shunt feed it for 160M. > > 73, > N2TK, Tony > > -----Original Message----- > From: topband-boun...@contesting.com [mailto: > topband-boun...@contesting.com] > On Behalf Of donov...@starpower.net > Sent: Friday, July 27, 2012 10:58 AM > To: topband > Subject: Re: Topband: Spark gaps > > An air gap using one to two inch diameter balls with only a one or two > millimeter gap provides a nearly uniform field resulting in the fastest > breakdown at repeatable and fairly breakdown voltages but capable of > withstanding kilowatt transmitter power levels. > > Ordinary carbon steel balls used in architectural applications should > provide adequate protection if they are inspected -- and replaced if > necessary -- after a lightning strike. For example, Wagner Industrial > sells > two inch diameter threaded steel balls for $11.00 each. There may be > alternative sources. > > > http://www.shopwagnerb2c.com/SPHERES/SPHERES_ST?categoryId=315e03cf-4f11-4ed > 9-8e89-9fea015509e5&filters=&sortby=1&page=1&pageSize=10&criteria= > > Very hard steel balls such as carbon or tungsten are ideal for withstanding > multiple lightning strikes without need for inspection and replacement, but > at higher cost. > > The balls should be aligned in the horizontal plane, to ensure rain, do not > bridge the gap. Preferably, the balls should be installed in a > weather/insect/rhodent proof enclosure. > > 73 > Frank > W3LPL > > > ---- Original message ---- > >Date: Fri, 27 Jul 2012 10:09:16 -0400 > >From: "Tom W8JI" <w...@w8ji.com> > >Subject: Topband: Spark gaps > >To: "topband" <topband@contesting.com> > > > >Has anyone looked at, or looked for, cheap electric fence gaps?? > > > >My system copper pipes near tower legs work great for me on rigid > >towers, I can bend them so they spring away from the tower and then > >slide an inner pipe in or out to set gap distance. I'm thinking of gaps > for > wire antennas. > > > >Maybe something is good from some other application that is a good bit > >better than a spark plug. > > > >_______________________________________________ > >UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK