But, what's the capacitance between the soil and the wire, through the
insulation. If it's enameled wire, the capacitance will be quite large, and
the impedance quite low. You've got lots of surface area, too...
The soil impedance will probably dominate over the interface
resistance/impedance. (probably is the operative word here... I'm too lazy
to run the calculation just now..)
----- Original Message -----
From: "Didier Juges" <didier@cox.net>
To: "Towertalk" <towertalk@contesting.com>
Sent: Wednesday, December 24, 2003 11:55 AM
Subject: Re: [allowed] Re: [TowerTalk] Ground radials
> I am not sure I would agree with that statement. The purpose of the ground
> wire network is to reduce resistive losses in the ground. The wire has an
> effect of reducing the resistivity of the ground under the antenna, on a
> macro basis. If you use insulated wire, you loose the benefit of
> conductivity between the wires and the soil, which overall will increase
> resistivity compared to non-insulated wire.
>
> For instance, below is a wire (to the left) and 2 points in the ground
(the
> X's, marked A and B)). With insulated wire, the resistance between A and B
> is purely driven by soil resistivity. With non-insulated wire, the current
> will jump from A to the wire, then travel through the wire up to the point
> closest to B, then jump to B through the soil. The overall resistance
> between A and B will be lower with non-insulated wire, so the losses
should
> be less.
>
> |
> |
> |
> | X (A)
> |
> |
> |
> |
> |
> | X (B)
> |
> |
> |
>
> 73,
> Didier KO4BB
>
> At 07:37 PM 12/22/2003, Gene Smar wrote:
> >Tom:
> >
> > Electrically it doesn't make a difference whether the wire's
insulated
> >or not. Mechanically, the insulation gives you a significant degree of
> >protection against corrosion and eventual disappearance of the radial
wire.
>
>
> _______________________________________________
>
> 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.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|