[BC] Elevated vs underground systems

[RSTYPE@aol.com]

In a message dated 2/12/2006 10:52:09 PM Eastern Standard Time, 
dpuopolo at usa.net writes:
Actually..
The radials work better if they are insulated. If you look at the current
distributuon, most of it is dissipated in the first 20 feet of non-insulated
wire. THis is the reason that ground screens improve things so mush - much
more area to dissipate. Insulated wire dissipates it more gracefully along the
entire length of the wire. This is also the theory as to why a few radials
that are elevated works so well.
Dana:

This is an old wives tale.  I was at the presentation of a paper presented at 
the NAB 15 or 20 years ago attempting to make a case for the superior 
performance of insulated radials.  After Ogden Prestholdt was done with his 
questions, it was obvious to all in attendance that the methodology used for the 
studies serving as the basis for this paper were flawed and that there is really no 
advantage to using insulated radials.  From an RF point of view, it should 
really make little difference difference since the ohmic contact loss between the 
radials and the soil is really an insignificant factor in what is really a 
fields phenomena, rather than a current phenomena.  From a static and lightning 
point of view, it would appear to be counterproductive to use insulated 
radials, which would increase the DC resistance to ground over the static discharge 
path.

Roy Stype