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Re: [TowerTalk] There's 'ground', and then there's 'ground'

To: "Frank Donovan" <donovanf@erols.com>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] There's 'ground', and then there's 'ground'
From: "Jerry Keller - K3BZ" <k3bz@arrl.net>
Date: Mon, 17 Jan 2005 09:00:46 -0500
List-post: <mailto:towertalk@contesting.com>
You know, Frank has a great idea. As an amateur, that's what I do too. Go and look. Do my best to copy what the pros do, but on an amateur scale. Be guided by actual practice, not just theory. I have great faith in the advice and pronouncements of the professionals we are lucky enough to have here on TT, but (as this thread demonstrates) there's plenty of room for professionals to disagree on the theoretical details. Lightning and RF don't care whether I'm a pro or a ham, so I pay attention, but as an amateur I just want to know what to do and how to do it...within the limits (physical, financial, and otherwise) imposed on me by my amateur status. All the discussion about the minute and arguable theoretical details just confuses me.

73, Jerry K3BZ

----- Original Message ----- From: "Frank Donovan" <donovanf@erols.com>
To: <towertalk@contesting.com>
Sent: Monday, January 17, 2005 7:39 AM
Subject: Re: [TowerTalk] There's 'ground', and then there's 'ground'



Keith,

If you work as a professional in the industry, or if
you're interested in spending several hundred dollars,
purchase the EIA/TIA and IEEE grounding and bonding
standards that provide exactly the engineering foundation
information you are seeking.  If you want to spend the
money, let it be known on the reflector and I'm sure
you will get the specifics.

Otherwise, I suggest you visit a commercial cell site, a
radio transmitter site, or a large computer facility in your
area.

Let us know how many braid straps you find.  If you
find any, let us know how long they are.

73!
Frank
W3LPL
donovanf@erols.com



----- Original Message -----
From: Keith Dutson <kjdutson@earthlink.net>
To: <towertalk@contesting.com>
Sent: Sunday, January 16, 2005 3:59 PM
Subject: RE: [TowerTalk] There's 'ground', and then there's 'ground'


>Its been well proven that braided strap has far too much inductance to be
of any utility above 2 MHz.

OK. So where is the proof?

I am thinking any writing you can find is based on the use of braid that
of
poor manufacture or has corroded, or both.  Poor or corroded braid can act
like many very small wires to create substantial impedance.  However, well
constructed braid acts more like a solid bar of metal, but with the
flexibility required for many installations.

Keith NM5G

-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Frank Donovan
Sent: Sunday, January 16, 2005 10:35 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] There's 'ground', and then there's 'ground'

Here's a clarification, pointed out by an attentive towertalkian:

My previous e-mail was not intended to refer to cables that use a braided
shield under a jacket.  A tight jacket compresses the braid and it's a
very
effective RF conductor, provided that the braid is not corroded.

Rather, my comment was intended to apply to to the inappropriate use of
braided strap for RF grounding or lightning protection.  Its been well
proven that braided strap has far too much inductance to be of any utility
above 2 MHz.

So... Lets try again:

Discard all forms of "braided" strap.
Braid is something a girl does to her hair.
Braided strap is a poor RF conductor and it's a terrible conductor of
lightning energy.

Use braided strap only for DC and audio applications, its just an inductor
for RF or lightning protection applications.

Here's an excellent reference from the many industry sources on this
topic:
http://members.cox.net/pc-usa/station/ground5.htm

73!
Frank
W3LPL
donovanf@erols.com



_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
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_______________________________________________

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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_______________________________________________


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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_______________________________________________

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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