On Mar 8, 10:01 pm, Cecil Moore wrote:
wrote:
On Mar 5, 11:40 pm, Ed wrote:
I am wondering how ground loss/resistance is effected by my
having the bottom/feedpoint of the antenna so high off the ground, not
to mention, I wonder how to calculate or guess what it is at all.

The bigger the vehicle, and the higher the mount, the lower the ground
losses.

The ARRL Antenna Book assumes ~10 ohms of ground loss
for mobile antennas. I've found that 12.5 ohms is the
lowest I can get for a 75m mobile antenna feedpoint.
--
73, Cecil http://www.w5dxp.com


Well, in my book, they state it varied for the size vehicle. They
state as
low as 4-6 ohms, but I agree, thats kinda optimistic...
But it still really doesn't matter as far as designing the antenna.
It's going to be the same no matter what... And it's consideration
of current distribution, etc, etc, will be important.
My antenna design will be the same , no matter what the ground
loss. So I don't worry about it too much. I just accept what I get..
BTW, my book is getting a little old, "90's something" so maybe they
have changed that section.
MK