Topband: radial length

[Bill Tippett]

Hi Rudy,

         On page 3 of your ground screen grid article:

http://www.antennasbyn6lf.com/files/ground_screen_grid_dimensions.pdf

you state:

We see that for this ground characteristic and frequency, 24" spacing 
in the grid
reduces the ground loss to about 1% of what it would have been 
without the screen.

I also believe both you and Tom feel 50 to 60 each
1/4 wave radials will get us close to optimum results.
At the far end of a system of 60 each 130' radials, the
ends of each radial are about 13' apart (2 Pi 130' / 60).
Taking a mental leap, coverage with 13' or less looks
like a solid conducting surface to 160m RF.  Closer
spacing (such as W0HG's chicken wire is wasted).

         How do we reconcile the difference in wire
spacing (2' versus 13') in the two systems?  Is it
due to one being a square grid and the other being
a radial system?  I'm now wondering how a square
grid of 21 X 21 260' wires (13' spaced grid) would
compare to a system of 60 130' radials.

         Another interesting point for DXpeditioners
is from your second paper:

http://www.antennasbyn6lf.com/files/160_m_vertical_measurements.pdf

A 16 radial system is down only 1.1 dB from a 64
radial system (Figure 5 below).  This seems fairly
consistent with the ~20 each 50' radials the Battle
Creek Special uses.  And by the way, the ends of
those radials are about 16' apart...not far from that
13' number that you and Tom like.

http://www.antennasbyn6lf.com/files/160_m_vertical_measurements.pdf

                         73,  Bill  W4ZV