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From: "Ashlock,William" <William.Ashlock@edwards.boc.com>
To: rsgb_lf_group@blacksheep.org
Subject: LF: RE: Re. Loops
Date: Fri, 8 Mar 2002 12:31:02 -0500
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Hi Laurie,

> ......so for tranmitting it would seem to be a good idea to have a bottom
wire on, or in the ground.

The problem is that the soil losses become fairly large. Think of the loop
wire with a huge donut-like AC magnetic field surrounding it. This field
doesn't seem to like the composition of the ground, which in effect, adds
series resistance to the loop circuit. I find the best compromise in
reduction of soil loss Vs maximizing the loop area by keeping the lower
conductor at least 5ft above ground. This distance could vary depending on
the soil type. The soil here in the Boston area, is composed of at least 60%
sand, covered by a thin layer of top soil. 
 
>This would have the added advantage of making it possible to use a very
thick or multiple thick >wires for this part of the loop thus reducing the
total loss resistance by almost 50%, with a
>consequent considerable increase in efficiency.

You can use multiple paralleled conductors on any portion, or all, of the
loop. These conductors must be separated by about and inch to keep the
Proximity Effect to a minimum. Forget about twisting these together as you
will find almost no reduction in Rac with the added wire.

>I can also recomend a bow and arrow  for launching wires over
trees,although I hav'nt reached  150 feet.

Think big! Just a year ago I was in the home-brew bow and arrow, kite
string, funk. Was lucky to reach 50 ft and only dreamed of putting a wire
over the whole mass of trees. Now, with the $90 (on sale) compound bow,
store-bought arrows, and monofillament fishing line, anything is possible
(including nailing the neighbors; so be carefull!). 

Bill A


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