Topband: Radial Wire System Comparison - (was adding a parasitic reflect

Paul Christensen w9ac at arrl.net
Thu Feb 1 09:39:23 EST 2018


>"The reason is that the standard DA ground system as far as I know, has
always involved strapping radials to a copper strap running along the line
of radial intersection, clipping off the radial wire that runs past the
strap."

Unless there's modeled or measured data, that's the "conventional wisdom,"
-- and it makes sense in those commercial installations where it's
impractical to use insulated wire that can withstand long-term soil
conditions.  Or, is there really that much cross coupling that results in
radial current cancellation when the wire is insulated?  

The wire is buried just below the ground surface and only the wire
insulation would come in contact between radial wires.  However, the
conductor-to-conductor distance at the overlap points would be very small.
For the answer, I'll likely need to run a NEC 4.2 model, and assign Z axis
distances of the radials that can be easily adjusted in NEC that results in
anything from a wired cross connection point to any spacing distance in
between radials.

>Why the teflon insulation?

Already acquired from a surplus supplier...a lot of it.  In addition to the
Teflon insulation, it's solid, silver-tinned copper, 18 AWG.  

Paul, W9AC



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