View Single Post
  #10   Report Post  
Old October 20th 07, 06:12 PM posted to rec.radio.amateur.antenna
art art is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 1,188
Default Fractal 10m Antenna

On 20 Oct, 09:34, "Mike Kaliski" wrote:
"art" wrote in message

oups.com...



On 20 Oct, 04:59, "Mike Kaliski" wrote:
"John Doe" wrote in message


om...Iam looking for
the construction article "FRACTAL Antenna for 10m" that
appeared sometime ago in I think either QST, Ham Radio, or 73 magazines.


I have a lot of spare time on my hands - so I thought I would like to
construct one and use it portable as I live in a Antenna Restricted
Community.


73's


As others have mentioned, several articles appeared in various magazines

snip.
Obviously you will need two mirror image windings to create a dipole
antenna,


Mike,
the definition I arrived at is that as long as the wire represents one
wave length, is resonant and in equilibrium while at the same time holding
to the L/C ratio of the material in question. This can be produced with
just two degrees of freedom by folding the wire at the half wave point and
then wind the two wires in pancake shape/form.
You can also wind two in series where capacitive actions between them can
create a variety of results.
The important point is that one must hold to the conditions set in the
definition (no exceptions)


Art


ideally as closely matched in dimensions as possible. Efficiencies
can approach 50% of a full sized radiating element.


Hope this helps


Mike G0ULI


Art

I agree. Incidently the origin of the idea for fractal antennae apparently
arose from the observation that hanging down the ends of a dipole, or
bending it to fit a limited site didn't affect the efficiency too much. A
university student decided to see just how much bending and could take place
before the antenna became unusable and hey presto, the fractal antenna was
invented and he had a thesis for his degree.

Mike G0ULI- Hide quoted text -

- Show quoted text -


Yup He is way ahead of the average ham but he did have an engineering
background
now he is making a lot of money with a product that the average hame
decries.
I was looking at Tom's page W8ti and I was very suprised to see that
he states
an antenna must be straight no less plus a lot more in accurate
statements.
He has written articles as have many on this newsgroup but as I have
stated before
believe what you want but often it is not correct.
On this newsgroup I am often reminded of the scene around madame
guillotine with
the . hoards of baying crowds of the ignorant looking for blood.
Have to make a correction on past statements tho, instead of one
wavelength radiator it should read
" one wavelength or longer" because of the genorous number of
harmonics.
Cheers
Art KB9MZ....XG (uk)