Welcome "Rogue Scholar" you have met your likes here--not "absolute answers"
but a mind that follows "the flow."

Warmest regards,
and welcome aboard,
John

"superas_1988" wrote in message
oups.com...
I'm not insisting in this particular angle.
In fact, this is only a starting point;
I am planning to alter the angle
and thus study many different variations of the antenna
so as to decide which is "the best".
Thank you all for your interest.

p.s.: Could you suggest a name based on its geometry?

Dear "superas_1988"
In my message of May 3, 2005, I used the name "Greek Double Rhombus."
Follows is a copy of that message. Note that comments about performance
above ground are not significant to your desire to use the antenna at 1.1
GHz.

-----
With a few minutes of unscheduled time and a need for a bit of intellectual
stimulation that could not be provided by the sophomoric responses to the
troll's messages on the news group, I decided to investigate the antenna put
forth by one or more of our Greek attendees. Unfortunately, the original
drawing of the antenna seems to have been withdrawn.

I assumed: a "small" angle of 60 degrees, #12 AWG Cu wire, and each of
the seven wires to be 21 meters long cut into 21 segments.

The resulting antenna has a FS fundamental resonance at about 7.45 MHz
with a 1.5:1 SWR bandwidth relative to 900 ohms of about 500 kHz. The next
higher resonance occurs at about 11.27 MHz with a 1.5:1 SWR bandwidth of
about 150 kHz relative to 200 ohms.

The antenna was elevated 40 meters above perfect ground and evaluated
at 7.45 MHz. For most elevation angles, the pattern has four lobes. The
two front lobes have a minor dip between them over elevation angles from
something like 10 degrees to something like 25 degrees. Below an elevation
angle of something like 10 degrees, the mid-lobe null is pronounced. Side
nulls are excellent. Front-to-back ratio is poor.

If one wished to cover a fairly large sector at 1 Mm or so and needed a
straight-on null of a distant station, this might be a useful antenna.

I did not consider the effects of rotating the antenna 90 degrees so
that the antenna is in the X-Y plane.

Here are the FS coordinates that I used for the ends of the wires:
(X,Y,Z)
0, -10.5,0
0, 10.5,0
0, -7.687, 10.5
0, -28.687, 10.5
0, -28.687, -10.5
0, -7.687, -10.5

The wire from 0,-10.5,0 to 0, 10.5,0 was driven at its mid-point.
-----

Good luck "superas_1988" with your investigation. Consider returning here
and telling us what you conclude about the antenna. It would be nice to
know your actual name.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"superas_1988" wrote in message
oups.com...
I'm not insisting in this particular angle.
In fact, this is only a starting point;
I am planning to alter the angle
and thus study many different variations of the antenna
so as to decide which is "the best".
Thank you all for your interest.

p.s.: Could you suggest a name based on its geometry?

To yammyr6:
Thanks for your suggestions,
but the geometry of the antenna has been approved
by my teacher and supervisor of my project,
and cannot be changed at that point.
Although, I will suggest that this altered antenna you are proposing
be studied by a colleague of mine as the next project of our antenna
lab.
I hope that it will be the evolution of my work...

I have read your message,
no need to post it again.
I suppose you did so
because I kept asking all of you
to suggest a name for the antenna.
Sorry, I know you already suggested one!

In your message you wrote:

"Note that comments about performance above ground
are not significant to your desire to use the antenna at 1.1 GHz."

When did I say it is my desire to use the antenna at 1.1 GHz???

As for my name,
I won't keep it hidden any more
as I have been very welcome by all of you to this newsgroup!
My actual name is Nick Kalantzis.

Dear Mr. Nick Kalantzis:
It is so much nicer with names.
As you concluded, I did not know that you had read my message of the
third of May. That is why I sent it again.
You asked about the 1 GHz observation: I remember some one from Greece
indicating that the antenna was to be used at 1111 MHz. It might have been
"Dimitris." What frequency range is of interest?

We look for reports on your work. Good luck. 73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"superas_1988" wrote in message
oups.com...
I have read your message,
no need to post it again.
I suppose you did so
because I kept asking all of you
to suggest a name for the antenna.
Sorry, I know you already suggested one!

In your message you wrote:

"Note that comments about performance above ground
are not significant to your desire to use the antenna at 1.1 GHz."

When did I say it is my desire to use the antenna at 1.1 GHz???

As for my name,
I won't keep it hidden any more
as I have been very welcome by all of you to this newsgroup!
My actual name is Nick Kalantzis.

Yes, it may be Dimitris.
In fact, our antennas are not to be used at 1111 MHz
(we do not even know if we'll have the time to build them).
This is only a frequency used by default in our lab to make
simulations.
The range of the simulation is not determined yet
but it will be around that common frequency.