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8-Loop Quad Stack

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amdx

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May 6, 2012, 4:43:34 PM5/6/12
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I found this picture of an 8 Loop quad.

2.32 GHz 8-loop spaced Quad stack with +-8° vertical and +-35°
horizontal HPBW.

http://i395.photobucket.com/albums/pp37/Qmavam/2g3antenna.jpg

Here's the original website, (no info)
http://www.kolumbus.fi/oh5iy/beacons/Beacons.html

Just for kicks.
Mikek

Jeff Liebermann

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May 6, 2012, 9:27:14 PM5/6/12
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Go kick thyself. That's a perfectly good antenna design with one
problem. It's twice as long as the crossed over quad wiring scheme
for the same gain. I'm too lazy to build an NEC2 model right now to
verify this. The straight sections are 180 phase shifting,
non-radiating, transmission lines. You can get the same 180 degree
phase shift by just alternating the phase of each adjacent quad by
crossing over the wires.

More quad quandary:
<http://www.g8ajn.tv/g4cya.html>
Notice that it's really 4ea double biquad antennas on a single
reflector, with 4 feed points. Those go to three Wilkinson power
combiners/splitters which are good for about 2-3dB total loss. In
other words, all the gain achieved by doubling the size of the antenna
is lost in the combiners.

Circularly polarized 1.28GHz biquad (just to be different):
<http://www.rcgroups.com/forums/showthread.php?t=1147430&page=28>
Nice design with a built in sleeve balun.

Impedance and gain of various loop antennas:
<http://www.dx-antennas.com/Loop.htm>

If you want to go insane with building quads, try a curtain quad:
<http://home.comcast.net/~ross_anderson/CurtainQuad.htm>
<http://home.comcast.net/~ross_anderson/CurtainQuadFigure11.htm>
<http://home.comcast.net/~ross_anderson/2400MHzAntenna.htm>

Or, you could extend a Sterba Curtain array:
<http://www.qsl.net/va3iul/Antenna/Wire%20Antennas%20for%20Ham%20Radio/34-Sterba%20Curtain%20Array%20Antenna.jpg>
<http://imageevent.com/holl_ands/notfortv/sterba;jsessionid=b3tbw0ob21.tiger_s>
While these are usually used for HF, it can be scaled down to 2.4GHz
and looks much like the double biquad.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

amdx

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May 7, 2012, 11:04:49 AM5/7/12
to
On 5/6/2012 8:27 PM, Jeff Liebermann wrote:
> On Sun, 06 May 2012 15:43:34 -0500, amdx<am...@knology.net> wrote:
>
>> I found this picture of an 8 Loop quad.
>>
>> 2.32 GHz 8-loop spaced Quad stack with +-8° vertical and +-35°
>> horizontal HPBW.
>>
>> http://i395.photobucket.com/albums/pp37/Qmavam/2g3antenna.jpg
>>
>> Here's the original website, (no info)
>> http://www.kolumbus.fi/oh5iy/beacons/Beacons.html
>>
>> Just for kicks.
>> Mikek
>
> Go kick thyself. That's a perfectly good antenna design with one
> problem. It's twice as long as the crossed over quad wiring scheme
> for the same gain. I'm too lazy to build an NEC2 model right now to
> verify this. The straight sections are 180 phase shifting,
> non-radiating, transmission lines. You can get the same 180 degree
> phase shift by just alternating the phase of each adjacent quad by
> crossing over the wires.
>
Thanks for the kick, Jeff.
I figured I'd get your knowledgeable opinion on the antenna I posted.
It's much appreciated.
I enjoyed the links you posted.
Thanks, Mikek

Allodoxaphobia

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May 7, 2012, 11:45:04 PM5/7/12
to
On Sun, 06 May 2012 18:27:14 -0700, Jeff Liebermann wrote:
> On Sun, 06 May 2012 15:43:34 -0500, amdx <am...@knology.net> wrote:
>
>>I found this picture of an 8 Loop quad.
>>
>>2.32 GHz 8-loop spaced Quad stack with +-8° vertical and +-35°
>>horizontal HPBW.
>>
>>http://i395.photobucket.com/albums/pp37/Qmavam/2g3antenna.jpg
>>
>>Here's the original website, (no info)
>>http://www.kolumbus.fi/oh5iy/beacons/Beacons.html
>>
>>Just for kicks.
>> Mikek
>
> Go kick thyself. That's a perfectly good antenna design with one
> problem. It's twice as long as the crossed over quad wiring scheme
> for the same gain. I'm too lazy to build an NEC2 model right now to
> verify this. The straight sections are 180 phase shifting,
> non-radiating, transmission lines. You can get the same 180 degree
> phase shift by just alternating the phase of each adjacent quad by
> crossing over the wires.

... and lose significant capture area.

miso

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May 24, 2012, 2:54:11 AM5/24/12
to

> ... and lose significant capture area.

I don't follow the argument over capture area. The phasing elements are
not "capturing" signal. This is much like though coax colinears where
half the antenna isn't capturing signal.
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