There is much discussion about the relative merits of the simple
vertical versus horizontal dipole antennas.

Their radiation patterns are well known. They are very broad in both
the vertical and horizontal planes. Both have have a null.

We need consider only the broadside, maximum, radiation from a dipole.

Most of the arguments can be settled by considering the elevation
angle of the path taken by the radio wave between the transmitting and
receiving stations. Followed by a little elementary geometry or
trigonometry. For present purposes a flat Earth can be assumed.

At an elevation angle of around 45 degrees the strength of radiation
received from vertical and horizontal antennas are about equal. (This
has nothing to do with Eznec take-off angles.)

The heights of the Ionospheric reflecting layers are -

E-layer = 70 miles, daylight only.
F1-layer = 140 miles, occasionally, in daylight only.
F2-layer = 190 miles, night-time.
F2-layer = 250 miles, in daylight.

From flat-Earth geometry, at an elevation angle of 45 degrees, the
distance between transmitting and receiving stations is twice the
height of the reflecting layer. Therefore, at this distance the
received signal strength can be expected to be about the same from
both types of antenna.

As the elevation angle decreases, the distance increases and radiation
from the vertical antenna increases. The radiation from the dipole
decreases. There is an extra propagation loss due to an increase in
radio path length but this equally affects radiation from both antenna
types.

As the elevation angle increases towards the vertical, distance
decreases, radiation from the dipole increases and radiation from the
vertical antenna decreases in strength. The radio path loss decreases
but the difference in pattern between the two antenna types is
maintained at the receiver.

With a spherical Earth, in daylight, using the F2-layer, at elevation
angles around 5 degrees, one-hop distances of 3,500 miles can occur.
With two hops, at angles of around 12 degrees, distances of 5,000
miles can occur.

For each additional hop there is loss in the layer and loss in the
reflection in the ground. Some parts of the radio path may be in
daylight and others in darkness. More than one layer may be involved.
Muli-path distortion occurs. Peculiar things happen and much depends
on frequency.

The low-angle performance of a half-wave dipole, even when radiating
broadside towards the receiver, is very poor in comparison with a
simple vertical.

On the other hand, a simple vertical does reasonably well when working
just across county because of the short propagation path, almost
straight up and down again, or even via the groundwave for very short
distances.
----
Reg, G4FGQ.

This rather oversimplified analysis overlooks an important factor. The
field radiated upward from an antenna seen at long distances (that is,
the sky wave as contrasted to the short-range surface wave) consists of
a vector sum of two components: one radiated directly, and one which is
inintially radiated downward then reflected from the ground. The ground
reflection alters both the magnitude and phase of the reflected
component depending on ground characteristics and the polarization of
the wave. At low angles, horizontally polarized waves are reflected very
well even when the ground is quite poor; vertically polarized waves
react differently. The resulting fields can fairly easily be calculated
manually if desired using simple geometry, equations for reflection
coefficient which can be found in Kraus and other references, and vector
addition. One thing you'll quickly discover is that the field from a
vertical does NOT monotonically increase as the elevation angle
decreases, but decreases below a moderate angle determined by the ground
characteristics. EZNEC (including the free demo) and other modeling
programs clearly show this important effect.

Roy Lewallen, W7EL

Reg Edwards wrote:
There is much discussion about the relative merits of the simple
vertical versus horizontal dipole antennas.

Their radiation patterns are well known. They are very broad in both
the vertical and horizontal planes. Both have have a null.

We need consider only the broadside, maximum, radiation from a dipole.

Most of the arguments can be settled by considering the elevation
angle of the path taken by the radio wave between the transmitting and
receiving stations. Followed by a little elementary geometry or
trigonometry. For present purposes a flat Earth can be assumed.

At an elevation angle of around 45 degrees the strength of radiation
received from vertical and horizontal antennas are about equal. (This
has nothing to do with Eznec take-off angles.)

The heights of the Ionospheric reflecting layers are -

E-layer = 70 miles, daylight only.
F1-layer = 140 miles, occasionally, in daylight only.
F2-layer = 190 miles, night-time.
F2-layer = 250 miles, in daylight.

From flat-Earth geometry, at an elevation angle of 45 degrees, the
distance between transmitting and receiving stations is twice the
height of the reflecting layer. Therefore, at this distance the
received signal strength can be expected to be about the same from
both types of antenna.

As the elevation angle decreases, the distance increases and radiation
from the vertical antenna increases. The radiation from the dipole
decreases. There is an extra propagation loss due to an increase in
radio path length but this equally affects radiation from both antenna
types.

As the elevation angle increases towards the vertical, distance
decreases, radiation from the dipole increases and radiation from the
vertical antenna decreases in strength. The radio path loss decreases
but the difference in pattern between the two antenna types is
maintained at the receiver.

With a spherical Earth, in daylight, using the F2-layer, at elevation
angles around 5 degrees, one-hop distances of 3,500 miles can occur.
With two hops, at angles of around 12 degrees, distances of 5,000
miles can occur.

For each additional hop there is loss in the layer and loss in the
reflection in the ground. Some parts of the radio path may be in
daylight and others in darkness. More than one layer may be involved.
Muli-path distortion occurs. Peculiar things happen and much depends
on frequency.

The low-angle performance of a half-wave dipole, even when radiating
broadside towards the receiver, is very poor in comparison with a
simple vertical.

On the other hand, a simple vertical does reasonably well when working
just across county because of the short propagation path, almost
straight up and down again, or even via the groundwave for very short
distances.
----
Reg, G4FGQ.

Reg:

Your simplistic analysis disagrees with my 50 years of operating local
contacts on 75 meters here in the southern US. Practical verticals are
universally 10 or more dB poorer than dipoles for local contacts, no matter
what the other variables. The very best quarter wave 66 foot vertical with
365 radials is about equivalent to a dipole lying on the ground for 0 to 250
mile contacts on 75. Forty meters performs a little closer to your
argument, but not much. Among long time local ragchewers, verticals are
considered to radiate equally poorly in all directions.

The NVIS nonsense also enters here. I have thrown back at the "proponents"
of NVIS that elevation angles of 45 degrees or less hardly qualify as NVIS
(properly NHIS, maybe?) but they continue to misuse common English to
further their specious arguments.

By the way, how much of the UK is within 500 miles of your QTH? I have to
exceed 500 miles just to get out of the state of Texas.

--
Crazy George
W5VPQ
My real address is my ham call atARRL.NET The ATTGlobal is a SPAM trap.
"Reg Edwards" wrote in message
...
There is much discussion about the relative merits of the simple
vertical versus horizontal dipole antennas.

Their radiation patterns are well known. They are very broad in both
the vertical and horizontal planes. Both have have a null.

We need consider only the broadside, maximum, radiation from a dipole.

Most of the arguments can be settled by considering the elevation
angle of the path taken by the radio wave between the transmitting and
receiving stations. Followed by a little elementary geometry or
trigonometry. For present purposes a flat Earth can be assumed.

At an elevation angle of around 45 degrees the strength of radiation
received from vertical and horizontal antennas are about equal. (This
has nothing to do with Eznec take-off angles.)

The heights of the Ionospheric reflecting layers are -

E-layer = 70 miles, daylight only.
F1-layer = 140 miles, occasionally, in daylight only.
F2-layer = 190 miles, night-time.
F2-layer = 250 miles, in daylight.

From flat-Earth geometry, at an elevation angle of 45 degrees, the
distance between transmitting and receiving stations is twice the
height of the reflecting layer. Therefore, at this distance the
received signal strength can be expected to be about the same from
both types of antenna.

As the elevation angle decreases, the distance increases and radiation
from the vertical antenna increases. The radiation from the dipole
decreases. There is an extra propagation loss due to an increase in
radio path length but this equally affects radiation from both antenna
types.

As the elevation angle increases towards the vertical, distance
decreases, radiation from the dipole increases and radiation from the
vertical antenna decreases in strength. The radio path loss decreases
but the difference in pattern between the two antenna types is
maintained at the receiver.

With a spherical Earth, in daylight, using the F2-layer, at elevation
angles around 5 degrees, one-hop distances of 3,500 miles can occur.
With two hops, at angles of around 12 degrees, distances of 5,000
miles can occur.

For each additional hop there is loss in the layer and loss in the
reflection in the ground. Some parts of the radio path may be in
daylight and others in darkness. More than one layer may be involved.
Muli-path distortion occurs. Peculiar things happen and much depends
on frequency.

The low-angle performance of a half-wave dipole, even when radiating
broadside towards the receiver, is very poor in comparison with a
simple vertical.

On the other hand, a simple vertical does reasonably well when working
just across county because of the short propagation path, almost
straight up and down again, or even via the groundwave for very short
distances.
----
Reg, G4FGQ.

Crazy George wrote:
By the way, how much of the UK is within 500 miles of your QTH? I have to
exceed 500 miles just to get out of the state of Texas.

Now George, I'll bet it's only a measley 420 miles. :-)
--
73, Cecil http://www.qsl.net/w5dxp

Not counting Mexico.

--
Crazy George
W5VPQ
My real address is my ham call atARRL.NET The ATTGlobal is a SPAM trap.
"Cecil Moore" wrote in message
et...
Crazy George wrote:
By the way, how much of the UK is within 500 miles of your QTH? I have
to exceed 500 miles just to get out of the state of Texas.

Now George, I'll bet it's only a measley 420 miles. :-)
--
73, Cecil http://www.qsl.net/w5dxp

Opinions of the many individuals depend on geographic lattitude, World
population densities, what bands happen to be favourites, G5RV's and
how much money there is in the bank. Let's try to remove these
distracting factors.

I'll put it in somewhat different "simplistic" terms.

Everything else being equal, the deciding factors are geometry and
trigonometry. The performance of a dipole is better at elevation
angles greater than about 45 degrees and the performance of a vertical
is better at lower angles. That's because the vertical and horizontal
antenna types are oriented at 90 degrees to each other. At elevation
angles around 45 degrees performance is about the same for both types.

The ground path distance corresponding to 45 degrees depends on height
of the ionospheric reflecting layers. Layer height depends on which
layer, mainly E or F2, day or night, summer or winter, and the solar
sunspot cycle.

(None of these important factors are taken into account by antenna
modelling programs. Propagation prediction programs DO take them into
account but, with them, geometry is also an essential factor.)

The range of distances at which vertical and horizontal antennas have
similar performances in daylight is from 140 miles (E-layer) to 500
miles (F2-layer), which falls to 370 miles at night.

But what decides whether a transmiiting antenna will be used or not is
NOT the distance to the receiver - it is the MUF (maximum usable
frequency)

The MUF is geometrically-derived which increases with distance and
with a decreasing elevation angle. It also changes with geographical
lattitude and sun angle. With the F2-layer the MUF can increase by 3
times the vertical critical frequency Fcrit. Thus, by using a vertical
low-angle antenna there are more bands and potentially more listeners
available.

Fcrit is the highest frequency which is reflected from a layer at
vertical incidence. At higher frequencies the wave passes straight
through. The MUF for high radiation angles and short distances is
therefore low. It does not increase very fast as the radiation angle
falls. It varies with night and day and the solar 11-year cycle. For
the E-layer in summer daylight Fcrit is about 3.5 MHz. For the
F2-layer in summer daylight it is about 6.5 MHz and about 5.5 MHz at
night. On winter nights Fcrit for the F2-layer is about 3.5 MHz.

Fcrit and high angle MUF's are subject to variation due to solar
activity. But in general only the 80m and 160m bands, and sometimes
40m, are open for short distance rag-chews. This restricts the
advantages of high-angle horizontal dipoles.

Finally, a horizontal dipole radiates best when broadside on. Unless
it is rotateable it has weaknesses in its service area.

If I had to choose, I'd always choose a half-wave 80m vertical in
preference to a half-wave dipole.
----
Reg.

On Wed, 1 Feb 2006 15:03:10 +0000 (UTC), "Reg Edwards"
wrote:

[bafflegab snipped]

If I had to choose, I'd always choose a half-wave 80m vertical in
preference to a half-wave dipole.


Me too, except that even with two acres, I can't meet the zoning
setback requirements for a 135 foot tall tower.

Finally, a horizontal dipole radiates best when broadside on. Unless
it is rotateable it has weaknesses in its service area.

If I had to choose, I'd always choose a half-wave 80m vertical in
preference to a half-wave dipole.
----
Reg.[/quote]

all antennas are a trade off
no antenna is better than some other antenna at everything
what is better can be very subjective

can you make it, do you half to buy it, can you aford it,
do you have room for it, half to hide it from the neighbors,
how high can you put it up, any big trees handy for hanging wires

must your antenna work all bands from 80 to 10
or just be great on one or two bands
what band, what use, rag chew, dxing, contest, what kind of test
Cal. qso party is quite diffrent from CQ wpx

80 meter 1/2 wave vert is 130 ft high how many ops
can put up a 130 ft vertical in their back yard

store bought ground mounted multiband verticals
good ones are expensive, nearly none are close to 1/4 wave high,
and a good ground system is a must

always lusted after a high gain high tower vert
but they now sell for about 875 dollars u.s.
and
my xly is not about to let me tear up her flower gardens
to lay out a ground system

on 75/80 out to 750 miles a 1/4 wave vert
is about as good as a dummy load

good in the clear, big vertical is a great dx antenna
but if you are going to dx with it on 160, 80, or 40
you are going to half to also put up a receive antenna
verticals are horrid receive antennas on low bands
as they pick up every bit of man made qrn

20 meter ground plane feed point at 35 or 40 ft is a wonderfull dx antenna

lower bands horizontal pattern of horizontal half wave dipole
do not come in to play unless at least 1/2 wave above ground

dipole has been the most popular amateur radio antenna for over 60 years
reason
easy to make, easy to put up and keep up,
for most general purpose use work very well

which is better dipole or vertical, is a question that has no answer

best antenna is the one you have up right now

mac w8znx

If I had to choose, I'd always choose a half-wave 80m vertical in
preference to a half-wave dipole.

In general, I'd prefer the dipole on 80m. But I work mostly
close in within say 600 miles on average. A dipole will smoke
most verticals at those short distances. If the dipole is at least
30-40 ft off the ground, it will still be capable of dx.
If I worked all dx on 80, I'd rather have the vertical, but being I
don't,
I prefer the dipole.
Each band is different, and it always depends on what path/distance
etc, I want to work as far as the preferred antenna.
In general, I'd prefer the vertical on 160m.
Dipole for 80 and 40, and usually 20.
I've tried both a 1/4 GP and a dipole on 20m for average use,
and found I prefer the dipole. Probably ditto for 17,15.
But on 10m, I prefer a 1/2, 5/8 vertical if I can't have a beam.
On 10m, you see quite a bit of local chatter, and most tend
to run vertical if they want a decent ground/space wave.
It also gives them a good dx signal. If you run a dipole on 10m,
your long haul will be good, but local operation fairly poor.
There really is no best type antenna except to suit the job at
hand. If I'm on 40m in the day, give me me a good dipole,
loop, etc . But 40m at night 800-1000 miles to the coasts?
I'd rather be sitting in my truck running the mobile. No joke.
It will do a better job vs my appx 40 ft tall dipole. That
was tested over and over again. No fluke of the band cdx.
On 40 at night, which is best will nearly always be distance
determined. Look at the lowly efficiency of the mobile vs
the dipole. At night, it doesn't really mean squat. What matters
is that you have radiation at the angle you need to make that
hop. My mobile spits more rf at the desired angle than my
40 ft high dipole does at those semi low angles despite being
half crippled as far as efficiency vs a full size antenna.
So polarization is nothing to ignore if you want the best
bang for the buck. I bet my mobile ant sitting sideways would
be pretty lame in that case. Or say take two like mobile antennas
and make a short dipole. It would stink up the place on those
long hauls vs the normal vertical mobile antenna. But it might be
slightly better in the day working 200 miles away.
The best is to have both. And use a switch to be able to
quickly compare. You will see some interesting things as
far as band cdx, signal fluctuations, etc over time.
It really boils down to using experience working the various bands,
at the various times of day, season, to know which will likely
be the best at a given time. It's 1.49 in the AM here right now.
If I had to get on 40m right now, give me the vertical any day.
That would change in a few hours though when I started losing the
long haul stuff and had it replaced by the various old farts and
rednecks I work on a more local scale. :/ I'd then be on the dipole.
MK

wrote:
If I had to choose, I'd always choose a half-wave 80m vertical in
preference to a half-wave dipole.


In general, I'd prefer the dipole on 80m. But I work mostly
close in within say 600 miles on average. A dipole will smoke
most verticals at those short distances. If the dipole is at least
30-40 ft off the ground, it will still be capable of dx.
If I worked all dx on 80, I'd rather have the vertical, but being I
don't,
I prefer the dipole.
Each band is different, and it always depends on what path/distance
etc, I want to work as far as the preferred antenna.
In general, I'd prefer the vertical on 160m.
Dipole for 80 and 40, and usually 20.
I've tried both a 1/4 GP and a dipole on 20m for average use,
and found I prefer the dipole. Probably ditto for 17,15.
But on 10m, I prefer a 1/2, 5/8 vertical if I can't have a beam.
On 10m, you see quite a bit of local chatter, and most tend
to run vertical if they want a decent ground/space wave.
It also gives them a good dx signal. If you run a dipole on 10m,
your long haul will be good, but local operation fairly poor.
There really is no best type antenna except to suit the job at
hand. If I'm on 40m in the day, give me me a good dipole,
loop, etc . But 40m at night 800-1000 miles to the coasts?
I'd rather be sitting in my truck running the mobile. No joke.
It will do a better job vs my appx 40 ft tall dipole. That
was tested over and over again. No fluke of the band cdx.
On 40 at night, which is best will nearly always be distance
determined. Look at the lowly efficiency of the mobile vs
the dipole. At night, it doesn't really mean squat. What matters
is that you have radiation at the angle you need to make that
hop. My mobile spits more rf at the desired angle than my
40 ft high dipole does at those semi low angles despite being
half crippled as far as efficiency vs a full size antenna.
So polarization is nothing to ignore if you want the best
bang for the buck. I bet my mobile ant sitting sideways would
be pretty lame in that case. Or say take two like mobile antennas
and make a short dipole. It would stink up the place on those
long hauls vs the normal vertical mobile antenna. But it might be
slightly better in the day working 200 miles away.
The best is to have both. And use a switch to be able to
quickly compare. You will see some interesting things as
far as band cdx, signal fluctuations, etc over time.
It really boils down to using experience working the various bands,
at the various times of day, season, to know which will likely
be the best at a given time. It's 1.49 in the AM here right now.
If I had to get on 40m right now, give me the vertical any day.
That would change in a few hours though when I started losing the
long haul stuff and had it replaced by the various old farts and
rednecks I work on a more local scale. :/ I'd then be on the dipole.


In support of Cecil's project of listening on a horizontal, while
transmitting on a vertical, I have tried an experiment this evening, and
will report on the results so far

While listening to an OK3 station this evening on 3.7995, I tuned two
separate radios to the frequency.

Radio 1 is an IC-745 with a Butternut HF6V. 20 some radials. decent
soil. Seems to work "well".

Radio 2 is an IC-761 on an OCF dipole. Also works pretty "well"


Noise level on the Vertical setup is S-8.

Noise level on the horizontal is S-4.

Mr. OK3 is at almost S-9 on the Vertical, and around S-7 to nearly S-8
on the horizontal.

Of course these two rigs have not been calibrated against each other.
So I can only say that at least from his location, he is putting a bit
stronger a signal (as far as the antenna is concerned) into the Middle
of Pennsylvania .

But here is the interesting thing. On the horizontal antenna, the
listening is a whole heckava lot more pleasant. Another item of interest
is that in a recent exchange between the OK3 and a VE3, I could catch
the Canadian station on my horizontal setup, while he was in the noise
on the vertical.

This is an early stage of the experiment, but
I believe that there is a lot to say with the lower noise on the
horizontal antenna station.

- 73 de Mike KB3EIA -