Spike wrote:
On 07/03/15 01:31, Jerry Stuckle wrote:

And BTW - don't worry about the trolls who have no idea what they are
talking about - but insist on showing their ignorance, anyway.

Your advice was noted at the time, Jerry, but thanks anyway.

Despite it, the trolls have now posted here; one didn't take out an HF
licence until the new code-less scheme passable by 5-year-olds became
available, and the other one had to ask advice, after being licensed at
the UK's top level, on which sideband to use.

Ah, still pushing that long-disproven lie, OM? A sign of desperation, it
seems. You do flail around so when you've shown yourself up.

--
STC // M0TEY // twitter.com/ukradioamateur

In rec.radio.amateur.antenna Spike wrote:

Imagine a short rod vertical aerial not connected to ground, for the
(say) 160/80/60/40m bands, as might be found in a typical /M set-up, fed
with RF energy and operating over ground of average conductivity.

Three different waves will be launched from this: the sky wave, the
space wave (including the reflected ray), and the surface wave. Each of
these have their own characteristics, inasmuch as the sky wave is
launched willy-nilly even if the band isn't open for that mode, the
space wave depends on the path to the receiver, and the surface wave
depends on the electromagnetic characteristics of the air and the
surface material, although to some extent the latter affects all the
waves generated.

These "waves" are actually called skywave and surface wave and are
a propagation phenomena.

See:

http://en.wikipedia.org/wiki/Skywave
http://en.wikipedia.org/wiki/Surface_wave
http://en.wikipedia.org/wiki/Line-of-sight_propagation

for how signals propagate.



--
Jim Pennino

On 07/03/15 01:49, wrote:
In rec.radio.amateur.antenna Spike wrote:

Imagine a short rod vertical aerial not connected to ground, for the
(say) 160/80/60/40m bands, as might be found in a typical /M set-up, fed
with RF energy and operating over ground of average conductivity.

Three different waves will be launched from this: the sky wave, the
space wave (including the reflected ray), and the surface wave. Each of
these have their own characteristics, inasmuch as the sky wave is
launched willy-nilly even if the band isn't open for that mode, the
space wave depends on the path to the receiver, and the surface wave
depends on the electromagnetic characteristics of the air and the
surface material, although to some extent the latter affects all the
waves generated.

These "waves" are actually called skywave and surface wave and are
a propagation phenomena.

See:

http://en.wikipedia.org/wiki/Skywave
http://en.wikipedia.org/wiki/Surface_wave
http://en.wikipedia.org/wiki/Line-of-sight_propagation

for how signals propagate.

Thanks to you and Jerry Stuckle for your replies.

Since a vertical aerial that I described initially emits all three of
these waves, I was interested in the relative amounts of the RF power
supplied to the antenna that goes into each. For example, does the sky
wave component take 90% of the power, leaving 10% for the space and
surface waves? What phenomena control this?


--
Spike

"Hard cases, it has frequently been observed, are apt to introduce bad
law". Judge Rolfe

Spike wrote:
On 07/03/15 01:49, wrote:
In rec.radio.amateur.antenna Spike wrote:

Imagine a short rod vertical aerial not connected to ground, for the
(say) 160/80/60/40m bands, as might be found in a typical /M set-up, fed
with RF energy and operating over ground of average conductivity.

Three different waves will be launched from this: the sky wave, the
space wave (including the reflected ray), and the surface wave. Each of
these have their own characteristics, inasmuch as the sky wave is
launched willy-nilly even if the band isn't open for that mode, the
space wave depends on the path to the receiver, and the surface wave
depends on the electromagnetic characteristics of the air and the
surface material, although to some extent the latter affects all the
waves generated.

These "waves" are actually called skywave and surface wave and are
a propagation phenomena.

See:

http://en.wikipedia.org/wiki/Skywave
http://en.wikipedia.org/wiki/Surface_wave
http://en.wikipedia.org/wiki/Line-of-sight_propagation

for how signals propagate.

Thanks to you and Jerry Stuckle for your replies.

Since a vertical aerial that I described initially emits all three of
these waves, I was interested in the relative amounts of the RF power
supplied to the antenna that goes into each. For example, does the sky
wave component take 90% of the power, leaving 10% for the space and
surface waves? What phenomena control this?


You've totally missed the point.

These "wave" phenomena are determined by the frequency and the condition
of the ionosphere, which is influenced by solar radiation.

A transmitting antenna knows nothing about any type of propagation.

The amount of any type of "wave" propagation that will happen depneds
on the antenna pattern, i.e. how much energy is radiated in any particular
direction, and the current ionospheric conditions.

There is a rule of thumb that says that maximum skywave occurs at an
antenna main lobe elevation of about 30 degrees, but it is only a
general rule of thumb. The exact angle will be determined by the
frequency and current condition of the ionosphere.



--
Jim Pennino

On 07/03/15 09:34, Jeff wrote:

Since a vertical aerial that I described initially emits all three of
these waves, I was interested in the relative amounts of the RF power
supplied to the antenna that goes into each. For example, does the sky
wave component take 90% of the power, leaving 10% for the space and
surface waves? What phenomena control this?

You are missing the point Spike, the antenna has no knowledge of how the
power that it radiates will propagate. It all depends on how much power
leaves the antenna at what angle, and what angle the antenna is
positioned relative to ground.

All the antenna has is a polar response of how much power is radiated at
what angle. It is that angle and the way the atmosphere reacts at any
particular time that controls the propagation of waves. This can vary
with time of day etc.

What controls the polar diagram is the physical dimensions of the
antenna, the height above ground, the conductivity of the ground, the
proximity of other objects, and other factors.

Thanks for the comments, Jeff. Perhaps I'm not being clear enough.

Look at the issue this way.... While it's clear that the totality of the
e/m emissions from from the antenna depend on factors such as length,
height, and ground, (and I originally assumed a particular set-up in the
OP) there are three distinct methods by which such a transmission can be
received: the sky wave path to a distant receiver, a space wave to a
line-of-sight receiver (that could easily be outside the surface wave
range) and the surface wave to a receiver tucked into the far side of a
hill with no sky wave or space wave path. It can be expected that
increasing the transmit power will increase the received signal at all
three locations, but the question I'd like to see answered is: what
proportion of the power supplied to the antenna goes to each of these
three phenomena, which all arise every time the transmitter is keyed.
They might all be connected by the conditions you mention, I'm not
suggesting they aren't, but for the set-up I originally described, what
are the proportions of the power supplied to the antenna that contribute
to each?

Or, to put it in yet another way...There might only be one 'wave'
launched from the set-up, that propagates in three different 'modes'
(for the want of a better word); so what controls the relative
power/energy with which each 'mode' is propagated?

The case I'm particularly interested in is the short-rod vertical not
connected to ground, in the MF/low-HF bands, as might be found in a /M
set-up.


--
Spike

"Hard cases, it has frequently been observed, are apt to introduce bad
law". Judge Rolfe

On 3/7/2015 5:13 AM, Spike wrote:
On 07/03/15 09:34, Jeff wrote:

Since a vertical aerial that I described initially emits all three of
these waves, I was interested in the relative amounts of the RF power
supplied to the antenna that goes into each. For example, does the sky
wave component take 90% of the power, leaving 10% for the space and
surface waves? What phenomena control this?

The antenna emits only one wave. It is its environment that determines
the strength at any distant point.

You are missing the point Spike, the antenna has no knowledge of how the
power that it radiates will propagate. It all depends on how much power
leaves the antenna at what angle, and what angle the antenna is
positioned relative to ground.

All the antenna has is a polar response of how much power is radiated at
what angle. It is that angle and the way the atmosphere reacts at any
particular time that controls the propagation of waves. This can vary
with time of day etc.

What controls the polar diagram is the physical dimensions of the
antenna, the height above ground, the conductivity of the ground, the
proximity of other objects, and other factors.

Thanks for the comments, Jeff. Perhaps I'm not being clear enough.

That's because you have a misunderstanding of radiation through a medium.

Look at the issue this way.... While it's clear that the totality of the
e/m emissions from from the antenna depend on factors such as length,
height, and ground, (and I originally assumed a particular set-up in the
OP) there are three distinct methods by which such a transmission can be

They are not distinct. They merge and separate based on the environment
in which they exist.

received: the sky wave path to a distant receiver, a space wave to a
line-of-sight receiver (that could easily be outside the surface wave
range) and the surface wave to a receiver tucked into the far side of a
hill with no sky wave or space wave path. It can be expected that
increasing the transmit power will increase the received signal at all
three locations, but the question I'd like to see answered is: what
proportion of the power supplied to the antenna goes to each of these
three phenomena, which all arise every time the transmitter is keyed.
They might all be connected by the conditions you mention, I'm not
suggesting they aren't, but for the set-up I originally described, what
are the proportions of the power supplied to the antenna that contribute
to each?

Or, to put it in yet another way...There might only be one 'wave'
launched from the set-up, that propagates in three different 'modes'
(for the want of a better word); so what controls the relative
power/energy with which each 'mode' is propagated?

There are no 'modes'. The wave is affected by its environment. It is
impossible to know what the signal strength at a distant point without
knowing all the characteristics of the medium through which it passes.

The case I'm particularly interested in is the short-rod vertical not
connected to ground, in the MF/low-HF bands, as might be found in a /M
set-up.

What is a /M setup?

On Sat, 07 Mar 2015 08:18:00 -0600, John S wrote:

What is a /M setup?

Mobile as in M0WYM/M


Charlie.
M0WYM.



--
Hello Wisconsin!

"Spike" wrote in message
...
Thanks for the comments, Jeff. Perhaps I'm not being clear enough.

Look at the issue this way.... While it's clear that the totality of the
e/m emissions from from the antenna depend on factors such as length,
height, and ground, (and I originally assumed a particular set-up in the
OP) there are three distinct methods by which such a transmission can be
received: the sky wave path to a distant receiver, a space wave to a
line-of-sight receiver (that could easily be outside the surface wave
range) and the surface wave to a receiver tucked into the far side of a
hill with no sky wave or space wave path. It can be expected that
increasing the transmit power will increase the received signal at all
three locations, but the question I'd like to see answered is: what
proportion of the power supplied to the antenna goes to each of these
three phenomena, which all arise every time the transmitter is keyed. They
might all be connected by the conditions you mention, I'm not suggesting
they aren't, but for the set-up I originally described, what are the
proportions of the power supplied to the antenna that contribute to each?

Or, to put it in yet another way...There might only be one 'wave' launched
from the set-up, that propagates in three different 'modes' (for the want
of a better word); so what controls the relative power/energy with which
each 'mode' is propagated?


You have to get it in your head there is not 3 differant waves launched from
the antenna. There is only one wave. As it leaves the antenna, whatever
the wave hits determins if it is ground, sky or whatever. The patern of the
antenna determins how much goes where.

With some antennas the patern is such much of it goes out to the horizon and
not much up in the air. Others radiate much to the vertical and not much
toward the horizon.

Think of it as throwing a rock into the middle a small pond. If there is
noting in the pond, the wave will go out toward the edges equally. If that
same rockis thrown in near the edge of the pond, some of the ripples will n
hit th eedge of the pond near the rock first while it will take some time
for the ripples to hit the other side.
You have the same origional wave, but its propogation is modified as to
where it is at . You do not have seperate waves leaving the rock.

On 07/03/15 15:57, Ralph Mowery wrote:
"Spike" wrote

Or, to put it in yet another way...There might only be one 'wave' launched
from the set-up, that propagates in three different 'modes' (for the want
of a better word); so what controls the relative power/energy with which
each 'mode' is propagated?

You have to get it in your head there is not 3 differant waves launched from
the antenna. There is only one wave. As it leaves the antenna, whatever
the wave hits determins if it is ground, sky or whatever. The patern of the
antenna determins how much goes where.

With some antennas the patern is such much of it goes out to the horizon and
not much up in the air. Others radiate much to the vertical and not much
toward the horizon.

Think of it as throwing a rock into the middle a small pond. If there is
noting in the pond, the wave will go out toward the edges equally. If that
same rockis thrown in near the edge of the pond, some of the ripples will n
hit th eedge of the pond near the rock first while it will take some time
for the ripples to hit the other side.
You have the same origional wave, but its propogation is modified as to
where it is at . You do not have seperate waves leaving the rock.

Thanks for the explanation and illustration.

Amateur (and professional) literature abounds with terms like sky wave,
space wave, and surface wave. There are sky wave radars, space wave
radars, and surface wave radars, for example. It isn't unreasonable to
use these as descriptors of what I was trying to find out. This was, to
recap, the relative proportions of the RF power delivered to the aerial
for each of these (whatever one wants to call them), for a typical /M
(mobile) set-up on the MF and low HF bands operating over ground of
average conductivity, a near everyday occurrence in the Amateur
community. The mechanism for the single wave that's transmitted
resulting in (whatever one wants to call them) isn't really of interest,
but the relative proportions that wind up in (whatever one wants to
call them) are.

In terms of your analogy, the rock being thrown into the pool close to
one edge of the pond is the equivalent of the short rod /M aerial
operating close to the ground, mounted on the vehicle. I can imagine
that if the edge of the pond is a gentle sandy slope, the reflected
waves will be different in nature that if the edge of the pond is a
vertical rock. However, this is merely reflecting the different ground
conductivities that might be experienced in the real-life Amateur
situation: some energy will go skywards to a distant receiver, some will
travel through air to a line-of-sight receiver, and some will go to a
receiver in the shadow of a hill that cannot receive either of the other
two (whatever one wants to call them).

--
Spike

"Hard cases, it has frequently been observed, are apt to introduce bad
law". Judge Rolfe

On 3/7/2015 6:13 AM, Spike wrote:
On 07/03/15 09:34, Jeff wrote:

Since a vertical aerial that I described initially emits all three of
these waves, I was interested in the relative amounts of the RF power
supplied to the antenna that goes into each. For example, does the sky
wave component take 90% of the power, leaving 10% for the space and
surface waves? What phenomena control this?

You are missing the point Spike, the antenna has no knowledge of how the
power that it radiates will propagate. It all depends on how much power
leaves the antenna at what angle, and what angle the antenna is
positioned relative to ground.

All the antenna has is a polar response of how much power is radiated at
what angle. It is that angle and the way the atmosphere reacts at any
particular time that controls the propagation of waves. This can vary
with time of day etc.

What controls the polar diagram is the physical dimensions of the
antenna, the height above ground, the conductivity of the ground, the
proximity of other objects, and other factors.

Thanks for the comments, Jeff. Perhaps I'm not being clear enough.

Look at the issue this way.... While it's clear that the totality of the
e/m emissions from from the antenna depend on factors such as length,
height, and ground, (and I originally assumed a particular set-up in the
OP) there are three distinct methods by which such a transmission can be
received: the sky wave path to a distant receiver, a space wave to a
line-of-sight receiver (that could easily be outside the surface wave
range) and the surface wave to a receiver tucked into the far side of a
hill with no sky wave or space wave path. It can be expected that
increasing the transmit power will increase the received signal at all
three locations, but the question I'd like to see answered is: what
proportion of the power supplied to the antenna goes to each of these
three phenomena, which all arise every time the transmitter is keyed.
They might all be connected by the conditions you mention, I'm not
suggesting they aren't, but for the set-up I originally described, what
are the proportions of the power supplied to the antenna that contribute
to each?

Or, to put it in yet another way...There might only be one 'wave'
launched from the set-up, that propagates in three different 'modes'
(for the want of a better word); so what controls the relative
power/energy with which each 'mode' is propagated?

The case I'm particularly interested in is the short-rod vertical not
connected to ground, in the MF/low-HF bands, as might be found in a /M
set-up.

What you are not grasping is that these "modes" of transmission have
*nothing* to do with the antenna really. As others have said, the
antenna only transmits different signal strengths in different
directions. How much power sent in a given direction is only loosely
connected to how much power ends up in these different reception modes
if at all.

The real issue is what do you expect to do with these numbers if you
have them? I expect that any equations you find for received signal
strength will already factor in these relative values giving a received
signal strength as a function of *total* power radiated from the antenna.

Are you trying to compare the effectiveness of different antenna for
different receiving modes?

--

Rick