On 19 Apr 2008 21:35:28 GMT, "Ed_G"
wrote:

In my case, I am considering the use of a vertical at a new residence
built on sand. Since I am not concerned about low angle radiation
characteristics, the Half Wave may be something to consider..... giving me
a fairly efficient vertical operation with some NVIS characteristics.

Hi Ed,

Efficient? A vertical has almost no Near Vertical radiation for Near
Vertical Incidence Skywave. You can get along with "almost no," or
you can simply use a low horizontal which would exhibit "a lot of"
Near Vertical Incidence Skywave.

Good ground, bad ground, radials, no radials won't change efficiency
much for the vertical's incidence overhead (there's a hole in that
pattern).

73's
Richard Clark, KB7QHC

Richard Clark wrote in
:

On 19 Apr 2008 21:35:28 GMT, "Ed_G"
wrote:

In my case, I am considering the use of a vertical at a new
residence
built on sand. Since I am not concerned about low angle radiation
characteristics, the Half Wave may be something to consider.....
giving me a fairly efficient vertical operation with some NVIS
characteristics.

Hi Ed,

Efficient? A vertical has almost no Near Vertical radiation for Near
Vertical Incidence Skywave. You can get along with "almost no," or
you can simply use a low horizontal which would exhibit "a lot of"
Near Vertical Incidence Skywave.

Good ground, bad ground, radials, no radials won't change efficiency
much for the vertical's incidence overhead (there's a hole in that
pattern).

73's
Richard Clark, KB7QHC


Richard,

By "efficient" I was referring to the transfer of power.... to a
presumed 50 ohm antenna input, not to any radiation characteristics !
As I understood it, a half wave vertical can give me this, with a
little effort. I also understood it to have a fairly high take off
angle.... which will certainly give me better in-state coverage than a
good low angle takeoff would..... wouldn't it?

Yes, I know a proper NVIS antenna would be far better than this....
that is why I used the term "some NVIS" characteristics.

TNX


Ed

Ed_G wrote:

Richard,

By "efficient" I was referring to the transfer of power.... to a
presumed 50 ohm antenna input, not to any radiation characteristics !
As I understood it, a half wave vertical can give me this, with a
little effort. I also understood it to have a fairly high take off
angle.... which will certainly give me better in-state coverage than a
good low angle takeoff would..... wouldn't it?

Yes, I know a proper NVIS antenna would be far better than this....
that is why I used the term "some NVIS" characteristics.

TNX


Ed

All the radiation from an antenna isn't concentrated at some "takeoff
angle", but radiates at all angles at various amounts. That distribution
is known as the "elevation pattern" and trying to replace it with a
single "takeoff angle" value loses nearly all the information about how
and where the antenna radiates. The half wavelength vertical radiates
very little above about 60 degrees elevation angle regardless of the
ground characteristics.

Roy Lewallen, W7EL