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Re: [TowerTalk] Coax Grounding on a tower.

To: <TOWERTALK@contesting.com>
Subject: Re: [TowerTalk] Coax Grounding on a tower.
From: "K8RI on Tower talk" <k8ri-tower@charter.net>
Date: Tue, 27 Jun 2006 05:14:27 -0400
List-post: <mailto:towertalk@contesting.com>


> Roger:
>
>     A couple of comments FWIW:
>
> Use an oversized flange nut from The Wireman ( 
> http://thewireman.com/newconnect2.html , P/N 1164 ) to fasten your barrel 
> connectors to the aluminum angle.  These babies have considerably more 
> surface area in

Fortunately I was introduced to those at the Midland swap a week ago. <:-))

contact with the angle than the normal thin nut that might come with the 
barrel connectors.  Thus your connection of the coax shield to the aluminum 
ground angle will be better able to handle the current from a strike. Maybe.
>
> Instead of installing additional connectors in your coax runs, consider 
> bonding the shield directly to the tower through a short pigtail and 
> wrap-around connector for the shield.  I homebrewed my own connectors for 
> this

Unfortunately I have more faith in my ability to install connectors than I 
do grounding braid without introducing leaks.

73 (past my bed time)

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
purpose in 2001 for my new tower.  The things look like Andrew connector 
kits.  Check out my TT posting at 
http://lists.contesting.com/archives//html/Towertalk/2002-07/msg00698.html . 
For me it was a lot easier to apply these connectors than to install PL-259s 
to the coax while on the tower.  Not installing PL-259s reduced the number 
of potential failure points in the coax runs as well.
>
> 73 de
> Gene Smar  AD3F
>
>
> -------------- Original message ----------------------
> From: "K8RI on Tower talk" <k8ri-tower@charter.net>
>> Due to basement work I've had to pull all the cables out of the conduit.
>> Man, but I was sore the other day and was wondering whey until I realized
>> I'd pulled between 1300 and 1500 feet of cable out of conduit the 
>> previous
>> evening.
>>
>> This has put me off-the-air with the main station which is probably why
>> 6-meters has been open the last couple of weeks.
>>
>> As this is turning into a rotator repair (It's hanging up again and the
>> thrust bearings are free), antenna repair, antenna removal, replace the 
>> pig
>> tails, and reroute the coax project I've decided that as long as the coax
>> has to go through connectors at the end of the pigtails at the top of the
>> tower I'm going to mount an aluminum angle across the face of the tower 
>> with
>> 3" UHF feed throughs.  Each of the current 4 pig-tails will fasten to a 
>> feed
>> through which will ground the brade to the tower at the top. The cables 
>> then
>> run down the inside of the NE tower leg where they are joined by two more 
>> to
>> the base and loop up into the junction box where they enter the 3" 
>> conduit
>> to the house.  The cables will be jointed by at least one or two more 
>> part
>> way down the tower, but there may be two less from the top.  The easiest 
>> is
>> to just say the number may vary.
>>
>> My thoughts are to either use another set of bulk head connectors on
>> Aluminum angle bracketed to the tower as at the top, or to clamp those
>> brackets to the leg of the tower using a hose clamp and spacers so the
>> center part of the feed through will be grounded to the tower leg.
>>
>> This will add one more set of connectors to the cables but from 
>> experience
>> and information gleaned from TT I'd say the insertion loss of the one 
>> extra
>> connector is going to be almost non existent. In addition the cables will 
>> be
>> grounded to the tower where they are leaving the tower.
>>
>> The new junction box at the house entrance will be putting the shield
>> grounds and the Polyphasors (sp?) right outside  the house at the point 
>> of
>> entry where they are currently just inside the house.  I think this will 
>> be
>> an bit of an added safety feature.
>>
>> One leg of the tower ground system will be entering the Hoffman box 
>> beside
>> the conduit, grounding the back plate inside and then continuing into the
>> house with the other cables. This #2 runs directly through to the house
>> ground for the electrical service as it's the only way I can get it 
>> there.
>> I'd have to tear up a rather expensive garage apron to get there outside 
>> and
>> that would make the grounds different length.
>>
>> This is going to get rid of the conduit coming through the basement wall.
>> It'll come in through the end plate of the floor joists and there will be 
>> no
>> cables showing below the basement ceiling.  At least that is the plan.
>>
>> Remember it's normal for this installation to take at least three 
>> lightning
>> hits a year and I think it's already had it three (or more) just in the 
>> last
>> storm.
>>
>> Any socially acceptable suggestions?
>>
>> TIA
>>
>> Roger Halstead (K8RI and ARRL 40 year Life Member)
>> N833R - World's oldest Debonair CD-2
>> www.rogerhalstead.com
>>
>> _______________________________________________
>>
>>
>>
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>
>
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