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: topband-bounces@contesting.com [mailto:topband-bounces@contesting.com]
> On Behalf Of donovanf@starpower.net
> 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" <w8ji@w8ji.com>
>> Subject: Re: Topband: Spark gaps
>> To: "Mike Waters" <mikewate@gmail.com>, "topband" <topband@contesting.com>
>>
>>> 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
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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