[TowerTalk] Odd radial field question

[jimlux]

Mark Robinson wrote:
> Yes I think that sounds like a great idea. I would look at brazing or 
> cadwelding the connections between the expansion joints. Join them in 
> several places so if one joint fails you will still be OK. I would bring out 
> solid copper side connections from the mesh  in lots of places and join them 
> to various radials in your radial field. None of these radials are resonant 
> so I wouldn't worry about the length to much.
> 

Rather than hooking up to ends of mesh, why not just lay a few pieces of 
bare copper wire on top of the mesh and bring them up to a connection 
point that's above grade and protected from the weather. You'd bond the 
rest of your system at that point.

If you bring things out from the side, that means there are tiny joints 
below grade, which is bad. (water gets in via capillary attraction, and 
eventually forces a bigger gap and corrosion)

You can spend time and effort brazing or welding, but overall, the 
concrete is a good enough conductor that it's probably not needed.

If you're really concerned, find out about admixtures for the concrete 
to increase its conductivity.  I think they work two ways: 1) it's 
actually something less resistive than the usual aggregate and 2) it is 
hydrophilic and tends to hold the water in the concrete.