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Old April 7th 10, 12:47 AM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

Hello everybody,

I hope everyone had a very Happy Easter. I have a spare 2:1 current
balun and would like to use it to feed a vertically oriented single-
band full-wave loop. I began to wonder; Can one feed two vertically
oriented full-wave loops perpendicular to each other with a common
feed point? Any opinions? Thanks in advance. As always, take care
es...

Vy 73 de Bert
WA2SI

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Old April 7th 10, 04:00 AM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

Can one feed two vertically oriented full-wave loops perpendicular to each other with a common feed point?

Many have.

73's
Richard Clark, KB7QHC
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Old April 7th 10, 10:29 AM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

On 7 abr, 01:47, WA2SI wrote:
Hello everybody,

I hope everyone had a very Happy Easter. I have a spare 2:1 current
balun and would like to use it to feed a vertically oriented single-
band full-wave loop. I began to wonder; Can one feed two vertically
oriented full-wave loops perpendicular to each other with a common
feed point? Any opinions? Thanks in advance. As always, take care
es...

Vy 73 de Bert
WA2SI


Hello Bert,

When you have identical loops, with same orientation, and distance
between them is less then 0.2 lambda, you can connect them in
parallel. Current in both loops will be the same (magnitude and
phase) and far field radiation pattern will also not change (with
respect to a single loop).

When the distance between the loops wire diameter, you will
experience an increase in useful bandwidth. Impedance at current
nodes will not change that much, but impedance at voltage nodes will
reduce. Due to the mutual coupling, you will experience some drift in
resonant frequency.

Feeding in opposite phase will give a complete new radiation pattern,
significant reduction in useful bandwidth and possibly reduction in
radiation efficiency.

Best regards,

Wim
PA3DJS
www.tetech.nl
in case of PM, don't forget to remove abc from the address.
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Old April 12th 10, 10:50 PM
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Default

Wonderful!

Last edited by Libra : June 1st 10 at 10:30 PM Reason: Politeness.
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Old April 13th 10, 04:08 PM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

On Apr 6, 6:47*pm, WA2SI wrote:
Hello everybody,

I hope everyone had a very Happy Easter. I have a spare 2:1 current
balun and would like to use it to feed a vertically oriented single-
band full-wave loop. I began to wonder; Can one feed two vertically
oriented full-wave loops perpendicular to each other with a common
feed point? Any opinions? Thanks in advance. As always, take care
es...

Vy 73 de Bert
WA2SI


I am taking your question as, 2 vertical loops, both hung from the
same skyhook, one broadside north/south, and the other broadside
east/west, and fed at the same point.

You get a more omni radiation pattern, but not full omni, there are
still lobes. This is much like 2 crossed dipoles (for the same band)
in an "X" configuration. Depending on height, you may not need the
2:1 balun. Check your impedance, a coax wound balun for a choke
may be all that is necessary.

73....Walter - K5EST


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Old April 13th 10, 06:36 PM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

On Tue, 13 Apr 2010 09:59:08 -0700 (PDT), JIMMIE
wrote:

Ive never seen them connected in parallel


We have talked about them at length here. What was described is a
quadrifilar helix - without the helix.

As there are so many details of construction are missing, little more
can be said, and our original poster appears to have gotten bored with
the topic.

73's
Richard Clark, KB7QHC
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Old April 13th 10, 07:35 PM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

On Tue, 13 Apr 2010 11:23:00 -0700 (PDT), Wimpie
wrote:

When you put them 90 degr. to each other (for example E/W and one N/
S), you will not get an omni-pattern. In that case you must make them
both off-resonance to get 90 degr phase time shift in generated fields
(or use a 90 degr. phase shifter and feed them separately).


Hi Wim,

You can do it with a goniometer. This antenna was first described 103
years ago by Bellini and Tosi.

73's
Richard Clark, KB7QHC
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Old April 17th 10, 01:06 PM posted to rec.radio.amateur.antenna
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Default Cophasing Two Full-Wave Loops?

On Apr 13, 1:36*pm, Richard Clark wrote:
As there are so many details of construction are missing, little more
can be said, and our original poster appears to have gotten bored with
the topic.

73's
Richard Clark, KB7QHC


Hello agn, everybody:

My apologies to you all. No, I have not gotten bored with this topic.
My job has rotating schedules as well as mandatory overtime.
Unfortunately, when one gets "stuck" for o/t, it's usually for an
entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!)
I either attend to my familial obligations or just crash. I did manage
to work a 5R8 station on the bottom of 80 so all was not lost - hihi.

I was thinking of making use of some unused space on my 50' fiberglass
mast by mounting a 2:1 balun and having two 10m vertically polarized
delta loops sharing the same feed points, specifically the
aforementioned balun. Yes, the goal is a single band, quiet and
physically unobtrusive single-band omni-directional. (Or at least
somewhat omni-directional without being a cloudburner.) Visualize, if
you will, two wire Christmas tree shaped wire loops, 90 degrees from
one another, fed at the center of their bottom legs up abt 30'.

Some might say, "why not just mount a vertical?" Well, I have the 2:1
balun and I figured that the loop would be much quieter.

Thanks so much for all your responses and have a safe and wonderful
weekend. Take care es...

Vy 73 de Bert,
WA2SI
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Old April 17th 10, 03:53 PM posted to rec.radio.amateur.antenna
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Posts: 625
Default Cophasing Two Full-Wave Loops?

On Apr 17, 8:06*am, WA2SI wrote:
On Apr 13, 1:36*pm, Richard Clark wrote:

As there are so many details of construction are missing, little more
can be said, and our original poster appears to have gotten bored with
the topic.


73's
Richard Clark, KB7QHC


Hello agn, everybody:

My apologies to you all. No, I have not gotten bored with this topic.
My job has rotating schedules as well as mandatory overtime.
Unfortunately, when one gets "stuck" for o/t, it's usually for an
entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!)
I either attend to my familial obligations or just crash. I did manage
to work a 5R8 station on the bottom of 80 so all was not lost - hihi.

I was thinking of making use of some unused space on my 50' fiberglass
mast by mounting a 2:1 balun and having two 10m vertically polarized
delta loops sharing the same feed points, specifically the
aforementioned balun. Yes, the goal is a single band, quiet and
physically unobtrusive single-band omni-directional. (Or at least
somewhat omni-directional without being a cloudburner.) Visualize, if
you will, two wire Christmas tree shaped wire loops, 90 degrees from
one another, fed at the center of their bottom legs up abt 30'.

Some might say, "why not just mount a vertical?" Well, I have the 2:1
balun and I figured that the loop would be much quieter.

Thanks so much for all your responses and have a safe and wonderful
weekend. Take care es...

Vy 73 de Bert,
WA2SI


I ran a single loop like you are talking about on 10M and had to use a
75 ohm 1/4 wl transformer to match the approximately 100 ohm impedance
of the loop.

I would think the two antennas mounted at right angles to each other
should be a pretty good match for 50 ohms.

Jimmie
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Old April 17th 10, 03:53 PM posted to rec.radio.amateur.antenna
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Posts: 625
Default Cophasing Two Full-Wave Loops?

On Apr 17, 8:06*am, WA2SI wrote:
On Apr 13, 1:36*pm, Richard Clark wrote:

As there are so many details of construction are missing, little more
can be said, and our original poster appears to have gotten bored with
the topic.


73's
Richard Clark, KB7QHC


Hello agn, everybody:

My apologies to you all. No, I have not gotten bored with this topic.
My job has rotating schedules as well as mandatory overtime.
Unfortunately, when one gets "stuck" for o/t, it's usually for an
entire extra 8-1/2 tour. When I finally get home, (A nice hike, btw!)
I either attend to my familial obligations or just crash. I did manage
to work a 5R8 station on the bottom of 80 so all was not lost - hihi.

I was thinking of making use of some unused space on my 50' fiberglass
mast by mounting a 2:1 balun and having two 10m vertically polarized
delta loops sharing the same feed points, specifically the
aforementioned balun. Yes, the goal is a single band, quiet and
physically unobtrusive single-band omni-directional. (Or at least
somewhat omni-directional without being a cloudburner.) Visualize, if
you will, two wire Christmas tree shaped wire loops, 90 degrees from
one another, fed at the center of their bottom legs up abt 30'.

Some might say, "why not just mount a vertical?" Well, I have the 2:1
balun and I figured that the loop would be much quieter.

Thanks so much for all your responses and have a safe and wonderful
weekend. Take care es...

Vy 73 de Bert,
WA2SI


I ran a single loop like you are talking about on 10M and had to use a
75 ohm 1/4 wl transformer to match the approximately 100 ohm impedance
of the loop.

I would think the two antennas mounted at right angles to each other
should be a pretty good match for 50 ohms.

Jimmie


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