i want build this antenna because seams to be the best choise for a
multiband array with gain and no loss(less than other) for field day
use.

If i buld it for 20mt it should work also on 15-10mt without traps.And
in this way i can use fisshing pole to build it.


http://www.hard-core-dx.com/nordicdx...wire/w8jk.html
The project find on this page seams to be perfect, i do not understand
the lenght are for half element or the full element

Thanks

sorry but the first question was mine. i don't know why was posted like
"wildboy" and not "ik7ytt".
so post made by "wildboy" and "ik7ytt" are made by same person.

On 10 Jan 2006 17:38:41 -0800, "ik7ytt" wrote:

i want build this antenna because seams to be the best choise for a
multiband array with gain and no loss(less than other) for field day
use.

If i buld it for 20mt it should work also on 15-10mt without traps.And
in this way i can use fisshing pole to build it.


http://www.hard-core-dx.com/nordicdx...wire/w8jk.html
The project find on this page seams to be perfect, i do not understand
the lenght are for half element or the full element

The diagram is not clear, is it.

The basic End-fire W8JK uses two half wavelength dipoles spaced an
eight of a wavelength. It has a half twist of the openwire line
between the dipoles, and it is fed at the centre of that line.

So, for 20m, each of the two dipoles will be about 10m long (end to
end), and they will be spaced about 2.5m apart.

(The diagram might lead you to think that each half of the dipole is
around 10m, but that not correct.)

Owen
--

Thanks for explain the diagram.
But now i have another doubt.
i have found on cebik home page an example of w8jk antenna.

You can seee at http://www.cebik.com/fdim/fdim9.pdf on page 6 and 7

in this project the full element is 44'(13.2m) but spacing is 22'
(6.6m)
So in this case the element is longher than 1/2wl ( i'm also reading
that the optimum is that the full element is from 1wl to 1.25wl, so
from 20m to 25m) and spacing is between 1/8 wl to 1/2wl.

What is the best choise?
If element is to short i may have very low impedence

On 10 Jan 2006 18:32:30 -0800, "ik7ytt" wrote:

Thanks for explain the diagram.
But now i have another doubt.
i have found on cebik home page an example of w8jk antenna.

You can seee at http://www.cebik.com/fdim/fdim9.pdf on page 6 and 7

in this project the full element is 44'(13.2m) but spacing is 22'
(6.6m)

Doesn't he say it is cut for the lowest frequency, and that is 30m or
10MHz) in Table 3?

So in this case the element is longher than 1/2wl ( i'm also reading
that the optimum is that the full element is from 1wl to 1.25wl, so
from 20m to 25m) and spacing is between 1/8 wl to 1/2wl.

What is the best choise?
If element is to short i may have very low impedence
--