[TowerTalk] Fwd: Static interference

[Leikhim, Joe]

UpTheTower@aol.com wrote:
> 
> ---------------------
> Forwarded message:
> From:   owner-towertalk@contesting.com
> To:     owner-towertalk@contesting.com
> Date: 97-05-16 05:21:22 EDT
> 
> >From k7lxc  Fri May 16 01:19:13 1997
> Received: from heather.greatbasin.com (root@heather.greatbasin.com
> [140.174.194.41])
>         by dayton.akorn.net (8.8.5/8.8.5) with ESMTP id BAA15938
>         for <towertalk@contesting.com>; Fri, 16 May 1997 01:19:12 -0400 (EDT)
> Received: from merlin.libelle.com (merlin.libelle.com [207.33.105.223])
>         by heather.greatbasin.com (8.8.5/8.8.5) with SMTP id WAA08724;
>         Thu, 15 May 1997 22:19:00 -0700 (PDT)
> Date: Thu, 15 May 1997 18:49:35 -0700
> From: George Worth <gworth@ibm.net> (by way of dick@merlin.libelle.com (Dick
> Flanagan))
> To: rptrown@clarc.org, towertalk@contesting.com
> Subject: HELP: Rpt noise when windy!!
> Organization: Libelle Productions, Inc., Minden, Nevada USA
> Reply-To: gworth@ibm.net
> Mime-Version: 1.0
> Content-Type: text/plain; charset=us-ascii; name="CRACKLIE.TXT"
> Content-transfer-encoding: 7bit
> Message-ID: <337BBD2F.1343@ibm.net>
> X-Mailer: Mozilla 3.01Gold (Win16; I)
> Newsgroups: rec.radio.amateur.equipment
> Content-Disposition: inline; filename="CRACKLIE.TXT"
> NNTP-Posting-Host: 166.72.137.82
> Lines: 31
> Path:
> szdc2!super.zippo.com!enews.sgi.com!su-news-feed4.bbnplanet.com!su-news-hub1.b
> bnplanet.com!news.bbnplanet.com!hunter.premier.net!hammer.uoregon.edu!azure.xa
> ra.net!xara.net!newsfeed.uk.ibm.net!ibm.net!news-m01.ny.us.ibm.net!ibm.net!new
> s1.ibm.net!166.72.137.82
> Xref: szdc2 rec.radio.amateur.equipment:35016
> X-Newsreader: Yet Another NewsWatcher 2.4.0
> 
> Al, I posted this on rec.radio.amateur.homebrew,misc and equip.
> Chupa Cabara
> 
> Gentlemen,
> I have a question for anyone that may have experienced "crackling" noise
> on their VHF repeater when the wind is blowing. Here is the scenario.
> We were donated a spot on a wooden utily pole which sticks out of the
> ground (the earth here is rock with a couple inches of soil over it)
> about 85 ft. There are 4x4 wooden cross arm systems at a couple places
> on the pole. At each cross arm there are 2) 4x4's bolted through the
> pole with u-clamps at the ends. This is where the 2" pipes are clamped to
> 4x4's for the antenna mounting. All 4 UHF machines work well. No noise.
> The VHF one does not. If the wind blows, the noise gets so strong it
> kicks incoming signals right out of the repeater. We have checked all
> antenna and feedline connections. They are good. What we did find was
> that if we wiggle or touch (with metal object) any (!!!ANY!!!) metal
> parts on the 4x4 support angle irons, 6 ga lightning ground wire which
> runs from the antenna mounts to central pole wire and down, pipes,
> anything metal at all, the noise is horrendous. What we suspect is that
> due to lack of RF ground, there is a pretty decent RF voltage/current,
> whatever, flowing or present on all the metal parts up there. If every
> piece of metal was bonded together and we nail copper flashing to the
> pole to connect RF grounds to, would this get rid of the dreaded
> "cracklies"?? How can we get a decent RF ground for VHF in the earth
> on top of this mountain? Any ideas would be more than greatly
> appreciated. Thanks for your help.
> 
> George
> 
> gworth@ibm.net

I think you have correctly diagnosed the problem/and a possible cure. 
What type of antenna are you using? Perhaps a decoupling skirt might 
help.

-- 
Joe Leikhim
Jleikhim@nettally.com

"tv dinner by the pool, 
i'm so glad i finished school" -F.Zappa 1967

"The Revolution will NOT be televised" -Gil Scott Heron



--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com