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Old April 13th 05, 05:48 PM
Frank
 
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"Richard Clark" wrote in message
...
On Mon, 11 Apr 2005 21:02:01 -0400, "Fred W4JLE"
wrote:
He claims that it is a "minium reactance antenna" thus the name.
http://www.smeter.net/wb4ene/mra-antenna.php


Hi Fred,

A simple glance at the SWR chart reveals it is in fact a Maximally
Reactive Antenna - at least the initials are preserved.

73's
Richard Clark, KB7QHC


A conventional monopole, resonant at about 7 MHz, would completely circle
the Smith Chart for almost two complete revolutions from 1.8 to 30 MHz. I
suppose that is what is meant by "MRA". Apart from that it would be
interesting to know the precise structure details to attempt a NEC model.
It looks suspiciously like the CFA class of antennas.

Frank


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Old April 13th 05, 05:58 PM
Fred W4JLE
 
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Thanks for the reply Richard...

He and his cohart were in the DX window on 75 working a CT0, his buddy had a
6 foot version and both got good reports. The large (18 foot) was running
1500 watts. The smaller one was running 200 watts. As to band conditions, I
later worked an EA with a 5/9+ running 100 watts to a G5RV. I was hoping
one of the EZNEC Gurus would take a look and give us the skinny.


When I looked at the photo, I had deja vu of a CFA.




"Richard Clark" wrote in message
...
On Mon, 11 Apr 2005 21:02:01 -0400, "Fred W4JLE"
wrote:
He claims that it is a "minium reactance antenna" thus the name.
http://www.smeter.net/wb4ene/mra-antenna.php


Hi Fred,

A simple glance at the SWR chart reveals it is in fact a Maximally
Reactive Antenna - at least the initials are preserved.

73's
Richard Clark, KB7QHC



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Old April 13th 05, 07:41 PM
 
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I could probably park my truck out in front of his
house, and do the same thing with my mobile
antenna...My mobile often outperforms my 35-40
ft high dipoles to DX on the lower bands....
To me, it seems to be a very ugly version of a
short top loaded monopole. Nothing more, or
less really....1500 w? He *should* be working dx,
or something is kuput....I work DX mobile with 100w
no problemo. That the "MRA junior" is only 200w doesn't
mean too much to me. He's still twice what I run...
If I were to run a MRA, I would at least install a hot tub
or spa in the middle...Add cup holders...Seats around
the outer section...etc...Shrubbery around the outside to
keep the old lady happy....Hell, with a used JATO engine,
you could probably take a trip in that thing...
I bet it would show on radar, until you ran into the underbelly
of that passing 737-700 that happened to be flying over the
house at the same time... Ouch....Can we spell headache?
MK

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Old April 15th 05, 07:26 PM
John Smith
 
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The rumor of UFOs'.... ya suppose? grin

Regards,
John

wrote in message
ups.com...
I could probably park my truck out in front of his
house, and do the same thing with my mobile
antenna...My mobile often outperforms my 35-40
ft high dipoles to DX on the lower bands....
To me, it seems to be a very ugly version of a
short top loaded monopole. Nothing more, or
less really....1500 w? He *should* be working dx,
or something is kuput....I work DX mobile with 100w
no problemo. That the "MRA junior" is only 200w doesn't
mean too much to me. He's still twice what I run...
If I were to run a MRA, I would at least install a hot tub
or spa in the middle...Add cup holders...Seats around
the outer section...etc...Shrubbery around the outside to
keep the old lady happy....Hell, with a used JATO engine,
you could probably take a trip in that thing...
I bet it would show on radar, until you ran into the underbelly
of that passing 737-700 that happened to be flying over the
house at the same time... Ouch....Can we spell headache?
MK



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Old April 13th 05, 10:47 PM
Richard Clark
 
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On Mon, 11 Apr 2005 21:02:01 -0400, "Fred W4JLE"
wrote:
http://www.smeter.net/wb4ene/mra-antenna.php


Hi All,

I pondered the page above, and then the website and chose a page at
random (well, directed drift perhaps given the link topic of Top Hat):
http://www.smeter.net/antennas/tophat2.php
and found:
Performance of Short, Vertical, Top-Capacitance-Loaded Antennas
Author: R.J.Edwards G4FGQ © 3rd October 2002

Funny, Reg, I thought you would have chosen to publish at
www.antenna.load.indicator.net instead. :-)

73's
Richard Clark, KB7QHC


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Old April 14th 05, 12:21 PM
Reg Edwards
 
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Funny, Reg, I thought you would have chosen to publish at
www.antenna.load.indicator.net instead. :-)

73's
Richard Clark, KB7QHC


================================

I had nothing to do with it. The text is an extract from the foreword
to one of my programs which, for some reason, somebody has thought fit
to copy.

On the other hand, your thought may be just another of your jokes, the
point of which eludes me.
----
Reg, G4FGQ


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Old April 14th 05, 02:06 PM
Cecil Moore
 
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Reg Edwards wrote:
On the other hand, your thought may be just another of your jokes, the
point of which eludes me.


Some postings are all balls and no points in order
to avoid corona. :-)
--
73, Cecil http://www.qsl.net/w5dxp


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Old April 15th 05, 07:29 PM
John Smith
 
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ALL kidding aside (well, almost), I have owned very large and impressive
(turkeys?) automobiles--admittedly--for little purpose other than to impress
others...
Why not an antenna???

Regards,
John

"Fred W4JLE" wrote in message
...
Has anyone taken a look at this antenna? I heard the designer on 75 last
night working a CT0, he says his is 18 foot in diameter. His buddy was
running a 6 foot version and 200 watts and worked the DX as well. He
claims
that it is a "minium reactance antenna" thus the name.

http://www.smeter.net/wb4ene/mra-antenna.php






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