Hi Thierry,

Yes, the cage idea should work well. I'd recommend 3 wires as the
very minimum, and I think 4 or more would be better. It also helps if
the form a cone, like the "Isopole" antennas, so the cage is well away
from the coaxial feedline, which would be centered in the cone.

If you use coax with a "copperweld" (copper-clad steel) center
conductor, perhaps you can strip 5 meters of the jacket and braid off
the end of the coax, and the coax is then one continuous run. In
fact, you can probably just cut the jacket and braid off of a short
section 5 meters from the end, to make the job easier. Then attach
some wires, even thin ones, to the feedline braid and run them back
along the line.

I'd recommend a choke balun, perhaps a few cm further along the line
from where the cage wires end. For single band use, you can coil up
some coax and even bridge across the coil with a capacitor to tune it,
connecting the capacitor to the braid -- that trick is useful if you
want to keep the coil small.

Cheers,
Tom


hello wrote in message .. .
HI
I want to put a dipole for 20m in my garden.
A tree and the home roof will be ok to fix the extremity.
My problem is the feed point : If IA center feed it , the feed line will
just hang at the center of the garden, something not acceptable by the
YL :-)

So I'm looking for a way to feed it by one "side".
I could endfeed it, but impedance matching is not so easy at such a high
impedance.
Then, after reading lots of post in this newsgroup, I read about the
sleeve antenna : generaly a vertical dipole where one leg is a sleeve.
Coax enter in the sleeve to the center feed point.
I think this antenna could work horizontaly and for HF and solve my
problem. Now, hanging horizontaly a 5m long metallic sleeve is surely
not a good idea, but at HF , I thing that man could replace the sleeve
by some wire cage.
So I end up with the idea of a cage or biconic dipole , with the coax
entering horizontaly in the middle of the cage to the center.

What do you think of this idea ?
How many wire for the cage 2 (a bowtie), 3, more ?
Do you have a better one for my particular constrains ?

Lots of questions, but I'm sure you will have lots of answers !

Thanks in advance

Thierry
F4DWV