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Old December 15th 04, 01:46 AM
William H. O'Hara, III
 
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"William H. O'Hara, III" wrote in
. 97.142:


I did quickly in the middle of the night. I will
look it over and see I can find some problem with
the wires. I used EZNEC demo 4.0.

Thanks
Bill

Maybe you should check your connections and try again. For
what it's worth, the pattern is like most large horizontal
loops, except for two large lobes in the direction of the
top corners of the tee.


I did get it to model SWR with high reactances(to me anyways).
Does this seem right? I dunno. Thanks

Bill
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Old December 15th 04, 07:08 AM
Richard Clark
 
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On Tue, 14 Dec 2004 18:46:22 -0600, "William H. O'Hara, III"
wrote:
I did get it to model SWR with high reactances(to me anyways).
Does this seem right? I dunno. Thanks


Hi Bill,

At this point, you need to provide more specifics. One, what
frequencies? Two, did they match your experience with a physical
model?

To answer your question lacking this information, yes this seems right
- at least somewhere in the panorama of all possible outcomes. It
stands to reason that ANY antenna, when looked at across a wide enough
spectrum, will reveal both resonances and high reactances, and many
combinations in between. This is just par for the course.

Now, if you find you are experiencing these high reactances in nature
as well as in modeling; then try one thing: Break the wire at a point
that is on the opposite side of the loop from the feedpoint and see
what happens.

73's
Richard Clark, KB7QHC
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Old December 16th 04, 12:10 AM
Ken Fowler
 
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On 14-Dec-2004, "William H. O'Hara, III" wrote:

"William H. O'Hara, III" wrote in
. 97.142:


I did quickly in the middle of the night. I will
look it over and see I can find some problem with
the wires. I used EZNEC demo 4.0.

Thanks
Bill

Maybe you should check your connections and try again. For
what it's worth, the pattern is like most large horizontal
loops, except for two large lobes in the direction of the
top corners of the tee.


I did get it to model SWR with high reactances(to me anyways).
Does this seem right? I dunno. Thanks

Bill


The reactive components are just an indication that the applied frequency is too high (+X), or too
low (-X). Adjust the frequency or the size of the loop till X = 0. Or just don't worry about it
and use high impedance parallel line with a tuner.

Ken Fowler
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Old December 16th 04, 02:04 AM
William H. O'Hara, III
 
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Now, if you find you are experiencing these high reactances
in nature as well as in modeling; then try one thing:
Break the wire at a point that is on the opposite side of
the loop from the feedpoint and see what happens.


I haven't strung the actual one yet.
My EZNEC model got everything high. There wasn't
a frequency better than 8:1. Everything was much
higher. I am going to try with the square loop.

Bill

Bill
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Old December 16th 04, 06:27 AM
Richard Clark
 
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On Wed, 15 Dec 2004 19:04:36 -0600, "William H. O'Hara, III"
wrote:
My EZNEC model got everything high. There wasn't
a frequency better than 8:1. Everything was much
higher. I am going to try with the square loop.


Hi Bill,

Still need some particulars:
What frequencies?
What length of wire?
How high?

73's
Richard Clark, KB7QHC


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Old December 17th 04, 01:23 AM
William H. O'Hara, III
 
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Richard Clark wrote in
:

On Wed, 15 Dec 2004 19:04:36 -0600, "William H. O'Hara, III"
wrote:
My EZNEC model got everything high. There wasn't
a frequency better than 8:1. Everything was much
higher. I am going to try with the square loop.


Hi Bill,

Still need some particulars:
What frequencies?
What length of wire?
How high?

73's
Richard Clark, KB7QHC



12# wire at 40 feet in the air with 90 feet to each
side for the basic square. I wanted to see it would
resonate on 80 down.

bill
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Old December 17th 04, 02:29 AM
Richard Clark
 
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On Thu, 16 Dec 2004 18:23:46 -0600, "William H. O'Hara, III"
wrote:

12# wire at 40 feet in the air with 90 feet to each
side for the basic square. I wanted to see it would
resonate on 80 down.


Hi Bill,

Even at a glance and simplistic conversion to metric would say you
were expecting 120M of wire to resonate at 80M. Far too much wire.

73's
Richard Clark, KB7QHC
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Old December 19th 04, 03:01 AM
William H. O'Hara, III
 
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Richard Clark wrote in
:

12# wire at 40 feet in the air with 90 feet to each
side for the basic square. I wanted to see it would
resonate on 80 down.


Hi Bill,

Even at a glance and simplistic conversion to metric would
say you were expecting 120M of wire to resonate at 80M.
Far too much wire.



I should actually double it. Tree configuration
is very tough. I do the have the option of potentially
doing a T shape or the box with 90 feet sides.

Not up yet.. Getting side tracked

Bill
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Old December 19th 04, 03:12 AM
Richard Clark
 
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On Sat, 18 Dec 2004 20:01:25 -0600, "William H. O'Hara, III"
wrote:
Far too much wire.

I should actually double it.

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