Topband: Ground loss query (re inverted L, antenna radiation resistance, & Jerry Sevick), Part II

[Dan Zimmerman N3OX]

> So let's table the discussion about folded antennas.  In the case of a
> simple vertical, where shorter height corresponds to lower radiation
> resistance, why does the effective series ground loss resistance introduced
> by a poor radial system appear to decrease with decrease in radiation
> resistance, instead of being constant?

The radiation resistance over soil is different than the radiation
resistance over perfect earth.  The radiation resistance depends on
the number, length, and  type of radials too:

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

This is a complicated problem with a lot of subtlety.  It gets even
weirder if the radials are long, like 3/4 wavelength.  I'll look at
the specific cases you're talking about later and see if I can give
any input.  What were your soil conditions in the model?

73,
Dan