View Single Post
  #9   Report Post  
Old February 24th 05, 09:55 PM
 
Posts: n/a
Default


KC1DI wrote:


Cebik says concerning the Inverted L antenna- which is similar to the


vertical Dipole that : "There is little evidence, despite the

vertical
position of one arm of the antenna, that the inverted-L would benefit


from a ground plane beneath the antenna. The actual low-angle gain of


the inverted-L will, however, vary with the quality of the soil in

the
region of reflection at a distance from the vertical arm. All

patterns
were taken over average soil, and soils that are either poor or

better
than average will tend to show a higher gain and lower take-off

angle,
at least on the fundamental frequency."

You might do well to read his articles at :

http://www.cebik.com/radio.html
He has quite a few dealing with the effects of different radial

systems
for vertical antennas.


I'd have to look at the articles later...But, as it is, I would
have to disagree with that. An inv-L is nothing like a 1/2 wave
vertical. He may be referring to an extended version, but normally,
an inv -L is a single wire loaded, 1/4 wave vertical,
and relies on the ground connection.
Max current is still at the base, and you can lose a lot to ground,
if it's poor. A longer 3/8, etc L would show lesser losses, but
radials would still help some.
MK