Sorry...couldn't resist.... http://www.youtube.com/watch?v=g23GiivXC78
On 7/27/2012 4:31 PM, kd9sv wrote: > Silly me, and to think they were probably referring to "Carbon Steel Balls" > not Carbon balls...de gary > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of [email protected] > Sent: Friday, July 27, 2012 5:26 PM > To: topband > Subject: Re: Topband: Spark gaps > > This link shows the base of a typical AM broadcast tower, with two hard > steel balls used as lightning protection. At kilowatt power levels its not > unusual to use a credit card to set the gap. > > http://www.thebdr.net/articles/steel/twrs/LimitingStatic.pdf > > 73 > Frank > W3LPL > > > > ---- Original message ---- >> Date: Fri, 27 Jul 2012 16:29:15 -0400 >> From: "Tom W8JI" <[email protected]> >> Subject: Re: Topband: Spark gaps >> To: "Mike Waters" <[email protected]>, "topband" <[email protected]> >> >>> Man, I don't know, Dave. How long have they been selling those carbon >>> balls >>> for that purpose? >> I've never seen a carbon ball in a lightning gap application. I'd have to >> see a few after being in action a long time before trusting them. >> >> Broadcast stations use hard metallic balls, as do electrical substations > and >> other applications where the peak voltage is near gap voltage. Polished >> round gaps have more consistent breakdown. >> >> If there is a great deal of headroom between operating and breakover >> threshold, a pointed gap works OK. >> >> _______________________________________________ >> UR RST IS ... ... ..9 QSB QSB - hw? BK > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > -- 73, Gary K9GS Greater Milwaukee DX Association: http://www.gmdxa.org Society of Midwest Contesters: http://www.w9smc.com CW Ops #1032 http://www.cwops.org ************************************************ _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
