I have modeled a 30 meter dipole, a Delta loop and a Quad loop (the loops
'hung' in a vertical plane). I have also spent hours reading various posts
and web articles on the 2 loop antennas. I am trying to better my situation
on 30 meters, my favorite band. Currently I have a dipole at about 38 feet,
which is as high as I can go with the top wire and the trees that I use are
no more than 48 feet apart (the dipole fits comfortably). I also have a wire
vertical with 16 radials which gets dismantled when grass cutting season
starts, it probably will go back up next fall. According to EZNEC, the Quad
loop is a little better than the Delta loop which is a bit better than the
dipole, but not by much. I did try a half square, and it seemed to work well
on transmit, but it was as noisy as the vertical on receive. The dipole is
nice and quite on receive, as it should be. The HS lasted 3 days before the
dipole went back up.
I've never used either loop but I did at one time use the inverted L loop.
It worked OK, but was also noisy on receive and I probably lost an S unit
due to low gain. The dipole seems to be the best antenna I've tried under my
circumstances so far, but I sure would like some opinions on the 2 mentioned
loops: Is either noticeable better than a dipole? Which one and why? Are
both nosier (important) than a dipole ( both vertical hung,bottom fed apex
down on the Delta loop and the Quad loop fed in the center of the bottom
wire)? Should I just stick with the dipole and spend my efforts elsewhere?
With the 48 feet between trees and my maximum height of 38 feet, is there
anything better I could try?
I KNOW what the modeling programs say, but I don't always believe them and
I am looking for PRACTICAL experience and personal opinions on the above 3
antennas. As it sits, I'm inclined to let well enough alone and stick with
the simple dipole, unless I can be convinced otherwise.

Thanks...
--

***** Jim Leder *****
IBM retiree since 1999
http://home.fuse.net/k8cxm

Jim Leder wrote:
Currently I have a dipole at about 38 feet,
which is as high as I can go with the top wire and the trees that I use are
no more than 48 feet apart (the dipole fits comfortably).

Install a center pole that keeps the angle between the
wires more than 90 degrees and keeps the ends at 38 ft.
--
73, Cecil http://www.qsl.net/w5dxp

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"Jim Leder" wrote in message
...
I have modeled a 30 meter dipole, a Delta loop and a Quad loop (the loops
'hung' in a vertical plane). I have also spent hours reading various posts
and web articles on the 2 loop antennas. I am trying to better my
situation on 30 meters, my favorite band. Currently I have a dipole at
about 38 feet, which is as high as I can go with the top wire and the
trees that I use are no more than 48 feet apart (the dipole fits
comfortably). I also have a wire vertical with 16 radials which gets
dismantled when grass cutting season starts, it probably will go back up
next fall. According to EZNEC, the Quad loop is a little better than the
Delta loop which is a bit better than the dipole, but not by much. I did
try a half square, and it seemed to work well on transmit, but it was as
noisy as the vertical on receive. The dipole is nice and quite on receive,
as it should be. The HS lasted 3 days before the dipole went back up.
I've never used either loop but I did at one time use the inverted L loop.
It worked OK, but was also noisy on receive and I probably lost an S unit
due to low gain. The dipole seems to be the best antenna I've tried under
my circumstances so far, but I sure would like some opinions on the 2
mentioned loops: Is either noticeable better than a dipole? Which one and
why? Are both nosier (important) than a dipole ( both vertical hung,bottom
fed apex down on the Delta loop and the Quad loop fed in the center of the
bottom wire)? Should I just stick with the dipole and spend my efforts
elsewhere? With the 48 feet between trees and my maximum height of 38
feet, is there anything better I could try?
I KNOW what the modeling programs say, but I don't always believe them
and I am looking for PRACTICAL experience and personal opinions on the
above 3 antennas. As it sits, I'm inclined to let well enough alone and
stick with the simple dipole, unless I can be convinced otherwise.

Thanks...
--

***** Jim Leder *****
IBM retiree since 1999
http://home.fuse.net/k8cxm



Jim,

If you want to mess with EZNEC some more, try feeding the quad loop at one
corner. Also at the top center. I have a sort of quad loop, actually a
trapazoid, hung vertically for 75 meters. My two 90 foot tree,
unfortunately, are only about 65 feet apart. So, to get all that wire up
there the bottom horizontal wire is longer than the top horizontal wire. I
am feeding it in one corner, per EZNEC calculations, with the center
conductor of the RG11 going to the vertical wire. This gives a combination
of vertical and horizontal polarization. Works quite well.

Haven't tried a delta loop, but seems to me you might want it upside down,
with the horizontal wire as high as possible. Feed the bottom apex. If I
sound contradictory, it is because I put up what fit, not what I wanted.

Tam/WB2TT

Jim,

I run a 40m inverted Delta Loop QRP and have worked (from
Annapolis, MD) most of Europe, several South American Countries,
a couple in the Middle East and all of the US (except Hawaii).
I use it on 40m, 30, 20m (probably best performance) 15m and
12m.... sometimes on 80m it will work "ok". I got N Carolina
on 80m one time.

The top of the loop is (roughly) 25-30 Feet up with the bottom
of the triangle only about 8 feet off the ground. That's one of the
big advantages of the DL over a dipole, i.e., height above ground
isn't as big a deal.

Short answer... I love it.

good luck
rob
n3hu


Jim Leder wrote:
I have modeled a 30 meter dipole, a Delta loop and a Quad loop (the loops
'hung' in a vertical plane). I have also spent hours reading various posts
and web articles on the 2 loop antennas. I am trying to better my situation
on 30 meters, my favorite band. Currently I have a dipole at about 38 feet,
which is as high as I can go with the top wire and the trees that I use are
no more than 48 feet apart (the dipole fits comfortably). I also have a wire
vertical with 16 radials which gets dismantled when grass cutting season
starts, it probably will go back up next fall. According to EZNEC, the Quad
loop is a little better than the Delta loop which is a bit better than the
dipole, but not by much. I did try a half square, and it seemed to work well
on transmit, but it was as noisy as the vertical on receive. The dipole is
nice and quite on receive, as it should be. The HS lasted 3 days before the
dipole went back up.
I've never used either loop but I did at one time use the inverted L loop.
It worked OK, but was also noisy on receive and I probably lost an S unit
due to low gain. The dipole seems to be the best antenna I've tried under my
circumstances so far, but I sure would like some opinions on the 2 mentioned
loops: Is either noticeable better than a dipole? Which one and why? Are
both nosier (important) than a dipole ( both vertical hung,bottom fed apex
down on the Delta loop and the Quad loop fed in the center of the bottom
wire)? Should I just stick with the dipole and spend my efforts elsewhere?
With the 48 feet between trees and my maximum height of 38 feet, is there
anything better I could try?
I KNOW what the modeling programs say, but I don't always believe them and
I am looking for PRACTICAL experience and personal opinions on the above 3
antennas. As it sits, I'm inclined to let well enough alone and stick with
the simple dipole, unless I can be convinced otherwise.

Thanks...

Jim,

I have also tried several horizontal and vertical combinations (everything
you mentioned except a quad loop) on 30 meters. After lots of very
unscientific experimentation and observation, I ended up with: A multi-band
vertical (Hy-gain AV-640) which I use as my 'reference' antenna, and a
horizontal delta loop at about 40 feet. I find the delta loop quieter than a
previous dipole or the AV-640 vertical; it has a flatter SWR curve (although
that doesn't seem to matter much on the narrow frequency allocation on 30
meters); and gives me better DX signal reception _almost_ all the time (once
in a while the vertical beats the loop, but it's rare). The delta loop's
characteristic impedance is 100 ohms, and I feed it in the corner with a 1/4
wavelength of RG/6 as a matching balun. Although the calculated length of
the loop should be 97.14 feet (frequ/983), I found that the best resonance
occurs when the total wire length is closer to 103 feet (lesson: you can
always cut it shorter, but can't cut it longer).

--
-larry
K8UT

"Jim Leder" wrote in message
...
I have modeled a 30 meter dipole, a Delta loop and a Quad loop (the loops
'hung' in a vertical plane). I have also spent hours reading various posts
and web articles on the 2 loop antennas. I am trying to better my
situation on 30 meters, my favorite band. Currently I have a dipole at
about 38 feet, which is as high as I can go with the top wire and the
trees that I use are no more than 48 feet apart (the dipole fits
comfortably). I also have a wire vertical with 16 radials which gets
dismantled when grass cutting season starts, it probably will go back up
next fall. According to EZNEC, the Quad loop is a little better than the
Delta loop which is a bit better than the dipole, but not by much. I did
try a half square, and it seemed to work well on transmit, but it was as
noisy as the vertical on receive. The dipole is nice and quite on receive,
as it should be. The HS lasted 3 days before the dipole went back up.
I've never used either loop but I did at one time use the inverted L loop.
It worked OK, but was also noisy on receive and I probably lost an S unit
due to low gain. The dipole seems to be the best antenna I've tried under
my circumstances so far, but I sure would like some opinions on the 2
mentioned loops: Is either noticeable better than a dipole? Which one and
why? Are both nosier (important) than a dipole ( both vertical hung,bottom
fed apex down on the Delta loop and the Quad loop fed in the center of the
bottom wire)? Should I just stick with the dipole and spend my efforts
elsewhere? With the 48 feet between trees and my maximum height of 38
feet, is there anything better I could try?
I KNOW what the modeling programs say, but I don't always believe them
and I am looking for PRACTICAL experience and personal opinions on the
above 3 antennas. As it sits, I'm inclined to let well enough alone and
stick with the simple dipole, unless I can be convinced otherwise.

Thanks...
--

***** Jim Leder *****
IBM retiree since 1999
http://home.fuse.net/k8cxm

"Larry Gauthier (K8UT)" wrote in message
...
Jim,

I have also tried several horizontal and vertical combinations (everything
you mentioned except a quad loop) on 30 meters. After lots of very
unscientific experimentation and observation, I ended up with: A
multi-band vertical (Hy-gain AV-640) which I use as my 'reference'
antenna, and a horizontal delta loop at about 40 feet. I find the delta
loop quieter than a previous dipole or the AV-640 vertical; it has a
flatter SWR curve (although that doesn't seem to matter much on the narrow
frequency allocation on 30 meters); and gives me better DX signal
reception _almost_ all the time (once in a while the vertical beats the
loop, but it's rare). The delta loop's characteristic impedance is 100
ohms, and I feed it in the corner with a 1/4 wavelength of RG/6 as a
matching balun. Although the calculated length of the loop should be 97.14
feet (frequ/983), I found that the best resonance occurs when the total
wire length is closer to 103 feet (lesson: you can always cut it shorter,
but can't cut it longer).

--
-larry
K8UT

Larry,

You don't apply the dipole fudge factor to full size loops. In fact, some
people claim it should be longer than a free space wavelength. I have seen
various formulas for the length between 1000/f and 1030/f feet. I started
out with 1030/f, but ended up shortening it by about 2 %. I suspect some of
that depends on how close to ground you are; also, I think my wire
stretched.

Tam/WB2TT

"Jim Leder" wrote in message
......................

I said in the original post that I didn't always trust what modeling
programs say, but in the case of 'length' I tend to agree with what it is
projecting. I've modeled both the Delta and Quad loop over and over, and
they always come out that the best overall length is closer to 1030/f.
1003/f is always too short, at least at 35-40 feet up. Whatever it is, as
Larry pointed out, it's easier to shorten the elements than add to them.
Larry, I use my vertical as you do: a reference antenna. However there are
times when it works better than the dipole. Depends on propagation effects.
Both have a place, but I can't (too lazy) keep the vertical in the grass
cutting season :+)) .

"Tam/WB2TT" wrote in message
news

"Larry Gauthier (K8UT)" wrote in message
...
Jim,

I have also tried several horizontal and vertical combinations
(everything you mentioned except a quad loop) on 30 meters. After lots of
very unscientific experimentation and observation, I ended up with: A
multi-band vertical (Hy-gain AV-640) which I use as my 'reference'
antenna, and a horizontal delta loop at about 40 feet. I find the delta
loop quieter than a previous dipole or the AV-640 vertical; it has a
flatter SWR curve (although that doesn't seem to matter much on the
narrow frequency allocation on 30 meters); and gives me better DX signal
reception _almost_ all the time (once in a while the vertical beats the
loop, but it's rare). The delta loop's characteristic impedance is 100
ohms, and I feed it in the corner with a 1/4 wavelength of RG/6 as a
matching balun. Although the calculated length of the loop should be
97.14 feet (frequ/983), I found that the best resonance occurs when the
total wire length is closer to 103 feet (lesson: you can always cut it
shorter, but can't cut it longer).

--
-larry
K8UT

Larry,

You don't apply the dipole fudge factor to full size loops. In fact, some
people claim it should be longer than a free space wavelength. I have seen
various formulas for the length between 1000/f and 1030/f feet. I started
out with 1030/f, but ended up shortening it by about 2 %. I suspect some
of that depends on how close to ground you are; also, I think my wire
stretched.

Tam/WB2TT

"Jim Leder" wrote in message
.....................

I said in the original post that I didn't always trust what modeling
programs say,

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

Very sensible!

Don't risk suffering from delusions of accuracy.

Modelling programs are invariably less acurate than the data stuffed into
them.

And the data stuffed into them nearly always contains nonsensical elements.

Yet results are religiously quoted by old-wives as being of gospel truth and
value, equivalent to misquoted, out-of-context, statements by Terman and
Kraus.

Who believes antenna relative gain figures stated in milli-bels at 14 MHz,
or the take-off angle is 20.7 degrees, when the DC ground conductivity is
average and ground permitivity, just as important, is not even mentioned?

And a 1000 other examples.

Jim Leder wrote:
As it sits, I'm inclined to let well enough alone and stick with
the simple dipole, unless I can be convinced otherwise.

That's probably what I would do. In most cases like that, I prefer
the dipoles over the loops...Why? Cuz in general, more of the current
will be up at that apex height, than the loop, which usually will
have to have wires dropping lower to the ground, in order to fit.
If I've got 35-40 ft of height, I prefer to keep the antenna currents
at that height. If you have a delta loop, or any other, usually the
bottom will be fairly close to the ground. More ground loss, and
in general less effective than having it all at 35-40 ft...The
small increase in broadside gain hardly seems worth it to me.
Usually, it's hardly noticable...If I wanted gain, I'd run parallel
dipoles phased, or something along those lines...
I know you don't have the room, but a simple EDZ is more effective
than a loop, as far as the broadside gain..And you can keep it
all up high...An EDZ on 30m would be about 96 ft or so total length..
Anyway, I don't think the loops would be a drastic improvement, if
much at all...But that's just my $2.31 worth...
MK

I have a 20 meter EDZ up about 35 feet and, yes, it is a very nice antenna.
The only problem I see with it is it's apparent narrow beamwidth. But, hey,
it's broadside NE/SW so I'm OK with that. I looked at one for 30, and know
that it would be nice to have one, but It would replace the 20 meter EDZ
(only place it would fit) and would not be high enough to be too effective.
I am very strongly leaning towards letting the dipole stay and MAYBE
getting off my duff and making the vertical more permanent and improving the
radial field.
I DO appreciate the comments. I have been debating this for some time now.
What else to do in mid winter in the Ohio but to think about spring time
antenna projects.

Jim


wrote in message
oups.com...

Jim Leder wrote:
As it sits, I'm inclined to let well enough alone and stick with
the simple dipole, unless I can be convinced otherwise.

That's probably what I would do. In most cases like that, I prefer
the dipoles over the loops...Why? Cuz in general, more of the current
will be up at that apex height, than the loop, which usually will
have to have wires dropping lower to the ground, in order to fit.
If I've got 35-40 ft of height, I prefer to keep the antenna currents
at that height. If you have a delta loop, or any other, usually the
bottom will be fairly close to the ground. More ground loss, and
in general less effective than having it all at 35-40 ft...The
small increase in broadside gain hardly seems worth it to me.
Usually, it's hardly noticable...If I wanted gain, I'd run parallel
dipoles phased, or something along those lines...
I know you don't have the room, but a simple EDZ is more effective
than a loop, as far as the broadside gain..And you can keep it
all up high...An EDZ on 30m would be about 96 ft or so total length..
Anyway, I don't think the loops would be a drastic improvement, if
much at all...But that's just my $2.31 worth...
MK