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Re: [TowerTalk] Wet setting conduit?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Wet setting conduit?
From: Jim W7RY <w7ry@centurytel.net>
Date: Sat, 02 Apr 2005 10:59:35 -0800
List-post: <mailto:towertalk@contesting.com>
Please tell me where Polyphaser it shows that:


  "According to the ARRL Handbook (or maybe it's the Antenna
Book) and Polyphaser, the optimum configuration is to install lightning
suppressors at *both* ends ".

I'm intimately familiar with the Motorola  R-56 Standards for 
Communications Sites, and it contains no discussion about using a lightning 
suppressor at both ends of the horizontal run between the base of the tower 
and the building.

Polyphaser does not make a readily available weatherproof lightning 
suppressor.

Now grounding the shield of the coax is recommended/required every 50-75 
feet. Both vertically and horizontally.

73
Jim W7RY
Motorola  Senior System Technologist



Polyphaser At 08:50 AM 4/2/2005, you wrote:
>Not necessarily. According to the ARRL Handbook (or maybe it's the Antenna
>Book) and Polyphaser, the optimum configuration is to install lightning
>suppressors at *both* ends -- at the tower and at the entry to the house. I
>believe the main idea is to protect the coax run between the house and
>tower, which is an important consideration if it's expensive hardline and/or
>buried in such a way that it would be hard to replace. I would think it's
>also good to have two sets of shunts to ground in case the suppressors at
>the tower get overloaded or fail. The shields should be grounded at both
>ends as well -- at the tower end to a system of ground rods and radials
>connected to the tower and at the house end to the single-point ground.
>
>73, Dick WC1M
>
> > -----Original Message-----
> > From: Gary Schafer [mailto:garyschafer@comcast.net]
> > Sent: Thursday, March 31, 2005 10:14 PM
> > To: Craig Sande
> > Cc: towertalk@contesting.com; Craig Lekutis; 'Gene Smar'
> > Subject: Re: [TowerTalk] Wet setting conduit?
> >
> >
> > Your lightning protection devices should go at the house not at the
> > tower. Ground the shields at the base of the tower though.
> >
> > 73
> > Gary  K4FMX
> >
> >
> > Craig Sande wrote:
> > > I finally decided not to risk any compromise to the base by
> > > introducing
> > > a total of 5 conduits.  The pour will proceed tomorrow
> > morning per the
> > > original engineering.  When the dust settles, I will take my time
> > > installing the conduit runs to the edge of the pier.  I'll
> > probably use
> > > a NEMA  box mounted nearby for the lightning arrestor
> > devices and have
> > > the conduit enter directly from below.  I'll run a 6"
> > copper strap from
> > > the NEMA box to the tower.  I'll be sure to snap plenty of
> > pictures and
> > > share my experience when complete.
> > >
> > > Regards,
> > >
> > > Craig, AE7I
> > >
> > >
> > > Craig Lekutis <craiglekutis@wirelessestimator.com> wrote:
> > >
> > >     Craig,
> > >
> > >     If it's a slab foundation and the PVC entries are not near the
> > >     anchor bolts then it might not be a problem since the
> > foundation is
> > >     probably designed for its compressive load and its overturning
> > >     moment. However, if it's a pier type design, it may be a problem
> > >     since it could affect interaction with the shaft and
> > anchor bolts.
> > >     Best practice is to do what you are going to do, check with your
> > >     engineer. You'll find addition information about
> > foundation design
> > >     at http://www.wirelessestimator.com
> > >     <http://www.wirelessestimator.com/> .
> > >
> > >     Best regards,
> > >
> > >     Craig
> > >
> > >
> > >
> >
> >
> >
> >
> >
>
>_______________________________________________
>
>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
>any questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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