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Old June 3rd 04, 09:41 PM
Irv Finkleman
 
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hello wrote:

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


Use two pieces of copper tubing for the elements. Connect one to the
center of the coax, the other to the braid. Bring the coax out through
the lower piece. This is also known as a coaxial-sleeve and a few other
variations on the name.
--
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Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada