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Dale Parfitt September 28th 03 01:52 PM



Warpcore wrote:

recent scientific investigations have found antennas based on a "fractal"
like pattern are better than their more conventional counterparts, but as
far as I know, they have not come up with a reason s.


Where is the fractal shape in this antenna?

Dale W4OP


Dale Parfitt September 28th 03 02:02 PM



Diverd4777 wrote:

Hi Michael:

I've found, that if you put up "More Wire" you get " More Signal".

A John Carr book says if you Quadruple the antenna length to get a 6 DB
( Noteceable) change in signal strength. Found that to be true,


Have you also noticed there is a 6dB increase in noise?
The only way to get increased sugnal strength for horizontal antennas ( i.e.
S/N) is to make the antenna directional- so there is an increase in one direction
at the expense of another direction. Not very useful unless you can rotate the
array.

Dale W4OP


Michael September 28th 03 06:28 PM

Hiya....

The very beginning of the receiving wire is attached directly to the
ICE-180.

The part of the diagram that is creating the question about the exact path
the receiving wire takes has to do with how the wire gets wrapped around the
very center of the top of the stone chimney and then directed to another
corner of the roof.

The receiving wire starts at the tap on the ICE-180 which is on the roof at
the bottom of the chimney. From there, it goes straight up three feet to
the top of the chimney. There it is wrapped around the top of the chimney
once and leads to the first corner of the roof. From the corner of the
roof, it feeds through the securing nylon tie that is secured to the gutter,
and then goes back on itself to the chimney. At the chimney, it's wrapped
around once more and heads to the second corner of the roof. From the
second corner, it's again fed through the securing nylon tie and then back
to the chimney. This is repeated for the other two corners of the roof.
The final return of the receiving wire to the chimney is wrapped around once
at the chimney to secure it and then terminated to an insulator. If you
look at the top of the chimney, although each "wrap-around" is of equal
length and shape, it appears as if there is a small coil of wire around the
top of the chimney.

--
Respectfully,

Michael

Home Page: http://md_dxing.tripod.com/
Northern NJ
R75 w/DSP, Kiwa agc/sync & audio mods
G5RV & 200ft longwire w/ICE-180
MFJ-1048 preselector
SoundBlstr Live PC card w/five piece Cambridge
speakers & full software mixer/eq.

"starman" wrote in message
...
Michael wrote:

Hiya...

One of my two antennas is a home brew 200 ft random wire antenna. It's

well
grounded and also makes use of a coax feed and an ICE-180 matching
transformer. Most importantly, it's set up and folded more like a piece

of
modern art rather then an antenna :-).


Where's the connection from the antenna to the matching transformer? I
see the end of the wire connected to an insulator on the chimney but
where's the other end (beginning) of the antenna wire that should be
connected to the ICE-180? Also, if the antenna wire is a 200-ft
continuous length, I don't see what path it takes to make the 'X'
pattern. It looks like two seperate doubled wires crossing over the
chimney top but not part of a continuous length of wire. It would be
helpful if you added some arrows to show the path of the wire as you
constructed it.


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starman September 29th 03 03:43 AM

Michael wrote:

Hiya....

The very beginning of the receiving wire is attached directly to the
ICE-180.

The part of the diagram that is creating the question about the exact path
the receiving wire takes has to do with how the wire gets wrapped around the
very center of the top of the stone chimney and then directed to another
corner of the roof.

The receiving wire starts at the tap on the ICE-180 which is on the roof at
the bottom of the chimney. From there, it goes straight up three feet to
the top of the chimney. There it is wrapped around the top of the chimney
once and leads to the first corner of the roof. From the corner of the
roof, it feeds through the securing nylon tie that is secured to the gutter,
and then goes back on itself to the chimney. At the chimney, it's wrapped
around once more and heads to the second corner of the roof. From the
second corner, it's again fed through the securing nylon tie and then back
to the chimney. This is repeated for the other two corners of the roof.
The final return of the receiving wire to the chimney is wrapped around once
at the chimney to secure it and then terminated to an insulator. If you
look at the top of the chimney, although each "wrap-around" is of equal
length and shape, it appears as if there is a small coil of wire around the
top of the chimney.

--
Respectfully,

Michael


Now I get it. Thanks for clarifying it. I think it would be difficult to
analyze such a non conventional design, especially when you have doubled
the wire to each of the four arms of the 'X'. However if you're
satisfied with it's performance, more power to you. If I had your set
up, I would try making some kind of loop, using the chimney as the
connecting point for the downlead (coax). You could also do an
inverted-V (dipole), with the chimney as the high point or a rhombic,
starting at one corner and extending to each of the other corners. Have
fun.


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Diverd4777 September 30th 03 12:10 AM


Bigger is better providing your receiver can handle the greater signal
levels without overloading. If not, you will be frustrated with all the
spurious (false) signals to be found throughout the receiver's tuning
range.


Point taken !

to guard against this, I bought a MFJ 1046 Pre selector;
If theres an overload situation on a frequency thats bothersome,
you flip it on

Knocks a few DB off the desired signal

- ANd all the wierd overloady stuff goes away !
Nice..

On the other side of this longwire antenna / pre selector
is the Icom R-75,
which has two amps,
that help bring up the strength of the weaker signals.

- I've picked up some of the radio traffic from Diego Garcia, and some
airport " transponders ( ??) from Santa Maria ( canary Islands)
- so the set up can't be all that bad.. !

Dan


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