View Single Post
  #1   Report Post  
Old November 30th 03, 09:14 PM
Art Unwin KB9MZ
 
Posts: n/a
Default 160 metre efficiency

I was wondering if anybody out there is using two mobile whip antennas
on top band.
The antenna would have max gain at 90 degrees but it should provide
good local contacts if placed at a height of 70 feet.
If one draws a circle as a radiation fields one could see where
the maximum gain is i.e. 90 degrees.
Now if you draw an antenna field with less than half the gain the
max would still be at 90 degrees but the gain loss at say 15 degrees
is minimul at best.
In my case when modeling my particular dipole I can make tremendous
strides
in efficiency if I attach wires at the end of the dipole that hang
to the ground
But when comparing gain say at 15 degrees horizontal there is no
worthwhile increase in gain ie less than 10% of the difference !
It would appear to me that if you are unable to put in a large area of
a ground system one would do better with shortened dipoles but well
away from ground
Comments
Art