"big boy now"
in reality the longer the wire the better.
But there is a down side the longer the wire the more you receive
including
interference. you could try useing an Antenna Tuner preselector...

Then how would you explain the performance equivalency of a 2Xwavelength
horizontal loop's performance to that of a 1/2wave dipole cut for same
frequency?
http://www.cebik.com/wire/horloop.html

The advantage of this type of loop is that it performs equally to a dipole
on
multiple frequencies. It is an excellent SWL antenna if you have the
real-estate.
Even a 1Xwavelength H-loop performs very well.

tianli_ wrote:
http://www.cebik.com/wire/horloop.html

The advantage of this type of loop is that it performs equally to a dipole
on
multiple frequencies.

The main disadvantage is that you could buy several hundred better
performing antennas for less than the first year's property taxes for
the land needed to construct the damn thing!

Yeesh. This makes my jokes about a 30-element MW log-periodic sound
practical by comparison.

Pull out your calculator. It's not that big.

"clifto" wrote in message
...
tianli_ wrote:
http://www.cebik.com/wire/horloop.html

The advantage of this type of loop is that it performs equally to a
dipole
on
multiple frequencies.

The main disadvantage is that you could buy several hundred better
performing antennas for less than the first year's property taxes for
the land needed to construct the damn thing!

Yeesh. This makes my jokes about a 30-element MW log-periodic sound
practical by comparison.

CW wrote:
"clifto" wrote...
tianli_ wrote:
http://www.cebik.com/wire/horloop.html

The advantage of this type of loop is that it performs equally to a
dipole
on
multiple frequencies.

Yeesh. This makes my jokes about a 30-element MW log-periodic sound
practical by comparison.

Pull out your calculator. It's not that big.

Imagine my surprise when my MW loop turned out to be only 1341 feet in
diameter, needing only 33 acres to hold it (41-1/3 if you own the entire
square the circle is inscribed in).

We'd need about 36 poles to hold it half a wavelength, or 1,054 feet,
off the ground.

Maybe we could rent Arecibo... is it big enough?

Imagine my surprise when my MW loop turned out to be only 1341 feet in
diameter, needing only 33 acres to hold it (41-1/3 if you own the entire
square the circle is inscribed in).

We'd need about 36 poles to hold it half a wavelength, or 1,054 feet,
off the ground.

Maybe we could rent Arecibo... is it big enough?

I don't think anyone is going to go through the trouble of building a H-loop
for the MW BCB. The original post inquired about the feasibility of a
longwire shaped into a "U". He was almost there by a few yards short of a
better performing horizontal loop.

The point of the discussion, and the links I included,
show that a modest horizontal loop has the same dB gain as a dipole AT
THE SAME HEIGHT. The loop advantage is that the dipole performs optimally
on its fundamental and harmonics ONLY, while the H-Loop performs equally
well on all frequencies at and above about its one wavelength circumference.

Read the links and learn.

JD,

From what you have written here; I soumds like
you built yourself a SkyWire Loop Antenna.

Except at Art Bell's compound.

On Sat, 26 Feb 2005 16:06:57 -0500, "Jack Painter"
wrote:


"tianli_" wrote
The point of the discussion, and the links I included,
show that a modest horizontal loop has the same dB gain as a dipole AT
THE SAME HEIGHT. The loop advantage is that the dipole performs optimally
on its fundamental and harmonics ONLY, while the H-Loop performs equally
well on all frequencies at and above about its one wavelength
circumference.

Well said. A horizontal dipole is optimal only between 1/4 wave to
preferably 1/2 wave height above ground. Anyone who thinks erecting a
horizontal loop at 1/2 wave height is easy, we've got a bridge in Arizona to
sell you. These horizontal loops are used, but they are typically strung
between the tops of several tall telephone poles erected in a circle.
Nothing you see in a hobbyists backyard.

Jack

Nice jd!

Many folks here are missing the point. It doesn't have to be 2X wavelength
or
even 1X wavelength. Just string up a horiz. loop anywhere you can and as
long as you can make it. Don't worry about height above ground or if it is
in a
circular, square or trapezoid, or what have you, configuration. If it is
anywhere
near as high as your proposed longwire or dipole it will work just as well
but
over a much broader swath of frequencies. Think of its performance as much
like a discone antenna at VHF & UHF - no gain over a half-wave vertical but
very broadbanded. The H-loop "generally" has omni-directional
characteristics
where as a dipole or longwire has definite nulls and peaks around the
compass.

I would guess that my H-loop is about at least 70-75 meters in circumference
at an average height of about 20 ft. It is strung around the edge of my
roof in
a large "L" configuration with the wire tucked under the roofing shingles at
strategic locations - invisible! It has survived several seasons of severe
weather and hasn't budged. I use it for SWLing as well as transmitting on
80-10 meters using a vintage Johnson Matchbox - sweet!

Compared to a dipole or a longwire it doesn't experience those "dips" in
reception on certain bands. Any "dips" that do occur are not as deep and
an antenna matchbox will easily make up for it.

Where anyone obtained the idea you must use dozens of 75+ ft telephone poles
around 100 acres of real-estate has simply never built or used a horiz.
loop.

Granted, it would undoubtedly work better at greater height, my horizontal
loop encircles a small section of my woods at varying heights of anywhere
from 6 feet to (maybe) 15 feet. I ran about 475 to 500 feet of wire,
hanging it off available tree branches as I went, in what is more or less
a
square with somewhat bulging sides. I couldn't tell you exactly how much
wire I used, other than I used enough to form a loop through the woods. I
couldn't tell you it's impedance. I feed it with coax through a home-made
1:1 transformer. I have no complaints with it's performance.

I think there's this expectation by folks new to the hobby that everything
has to be "labratory" perfect or it's a waste of time. In my experience, I
have found that wire antenna's are *very* forgiving of imperfections.
Granted, they will not perform as well as something carefully constructed
in a labratory environment, but they will *still* work - and there's even
odds (or better than even) they will work better than expected!

My rule of thumb is: "As much wire as you reasonably can, as high as you
reasonably can." In different situations, that could be 30 feet of wire at
house-eave level -or- a 2wl horizontal loop at 1wl above dirt. Just do
what you can, and are interested in trying, and don't sweat the details
until *after* you establish a baseline.

-=jd=-
--
My Current Disposable Email:

(Remove YOUR HAT to reply directly)

"tianli_" (and jd) wrote in message
...
Nice jd!

(( Comments inserted between text ))


Many folks here are missing the point. It doesn't have to be 2X
wavelength
or
even 1X wavelength. Just string up a horiz. loop anywhere you can and as
long as you can make it. Don't worry about height above ground or if it
is
in a
circular, square or trapezoid, or what have you, configuration. If it is
anywhere
near as high as your proposed longwire or dipole it will work just as well
but
over a much broader swath of frequencies. Think of its performance as
much
like a discone antenna at VHF & UHF - no gain over a half-wave vertical
but
very broadbanded. The H-loop "generally" has omni-directional
characteristics
where as a dipole or longwire has definite nulls and peaks around the
compass.

I would guess that my H-loop is about at least 70-75 meters in
circumference
at an average height of about 20 ft. It is strung around the edge of my
roof in
a large "L" configuration with the wire tucked under the roofing shingles
at
strategic locations - invisible! It has survived several seasons of
severe
weather and hasn't budged. I use it for SWLing as well as transmitting on
80-10 meters using a vintage Johnson Matchbox - sweet!


--
While it sounds like you have little more than a cloud warmer there (if
otherwise please do advise), you're right that it costs very little to run a
few hundred feet of wire anywhere you can get it. The result could be a
good listening antenna. What it won't normally be is a good transmitter,
unless it meets mimimum design conditions.

Also, don't you worry what kind of RF you illuminate the house with? It
looks to me like people inside could be as close as 2 or 3' from your
antenna, and at most HF frequencies that is way too close to 100+w transmit
power.
--


Compared to a dipole or a longwire it doesn't experience those "dips" in
reception on certain bands. Any "dips" that do occur are not as deep and
an antenna matchbox will easily make up for it.

Where anyone obtained the idea you must use dozens of 75+ ft telephone
poles
around 100 acres of real-estate has simply never built or used a horiz.
loop.


--
That would be me. I have seen one in use, just never replicated by a
hobbyist (yet). Without the near 1/2 wave design-elevation, a horizontal
wire antenna becomes NVIS (or cloud warmer). We've all heard of people
doing this with their rain gutters for years, but that doesn't translate to
a worthwhile effort when compared to most achievable antenna designs.
--

Granted, it would undoubtedly work better at greater height, my
horizontal
loop encircles a small section of my woods at varying heights of
anywhere
from 6 feet to (maybe) 15 feet. I ran about 475 to 500 feet of wire,
hanging it off available tree branches as I went, in what is more or
less
a
square with somewhat bulging sides. I couldn't tell you exactly how much
wire I used, other than I used enough to form a loop through the woods.
I
couldn't tell you it's impedance. I feed it with coax through a
home-made
1:1 transformer. I have no complaints with it's performance.

I think there's this expectation by folks new to the hobby that
everything
has to be "labratory" perfect or it's a waste of time. In my experience,
I
have found that wire antenna's are *very* forgiving of imperfections.
Granted, they will not perform as well as something carefully
constructed
in a labratory environment, but they will *still* work - and there's
even
odds (or better than even) they will work better than expected!

My rule of thumb is: "As much wire as you reasonably can, as high as you
reasonably can." In different situations, that could be 30 feet of wire
at
house-eave level -or- a 2wl horizontal loop at 1wl above dirt. Just do
what you can, and are interested in trying, and don't sweat the details
until *after* you establish a baseline.

-=jd=-

True enough.

Jack

"-=jd=-" wrote
/snip
For now, I have no interest in talking. Though, I have often
thought of working towards the General ticket just to see if I could pass
the tests, simply out of personal curiosity.

-=jd=-

I couldn't memorize 1 wpm of Morse code in the Boy Scouts, doubt that it is
going to happen 35 years later ;-) I'm on the air for the USCG and they
don't care if we know code or not. A smaller and smaller number of older
chiefs and officers who were hams for a hundred years still know code in the
guard - not much interest in it or radio in general by younger generations,
even when they operate them for a living. Computer networking is what
drives the communication business today, the radios themselves seem a small,
mostly forgotten part of it.

Sorry to have gotten off-topic with the longwire - for listening it is
certainly the most forgiving of any configuration imaginable.

Jack