[Antennas] Ground losses in ohms??

[Sam Morgan]

Wile reading the article:
"Short, Coil-Loaded, Ground-Mounted, Vertical or Slanting Antennas" 
http://www.smeter.net/antennas/loadcoil.php

There is a program called loadcoil.exe there. which I started to use.
I tried plugging in the data for my bug catcher, which rests on the tar and 
gravel, flat, roof of my apartment building.

But not to far into the equations, it ask me for my "ground losses in ohms".
Duh, before I had run into poor/fair/and good as my options, lots of room for 
guessing with those terms. Never been asked for a numerical value before.


In the article it mentions 2 to 12 ohms for small to large vehicle roofs and 
then goes in to ground mounted radials. I'm afraid my apartment landlord might 
just freak out if I tried erecting a 33' (1/4 wavelength) vertical to help me 
measure and then determine the actual feedpoint resistance. It took two and a 
half years to get the shorty on the roof.  ;-)

So my question to the group is, what would they use for the ohms of resistance 
of a 12' tall center loaded vertical on 40m, when the ground consists of sixteen 
13' long wires in a circle on that tar and gravel roof?

-- 
GB & 73's
KA5OAI
Sam Morgan