Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Nov 30, 6:27*pm, Richard Clark wrote:
However, resourcing the top engineers of the AM field for their
observations of sky-wave and ground-wave field strengths (a typical
service application) where they combine destructively (the "fading
wall"); at a distance of 70 miles, for 50% of the time, both signals
are equal (with propagation variations of phase accounting for
fading).
__________

With more research you'll find that the fading zone is not located a
fixed 70 miles away from every AM station.

The fading zone occurs wherever the skywave and groundwave are
approximately equal, and that varies with frequency, the elevation
pattern of the monopole, the conductivity of the groundwave path, and
the altitude of the ionosphere.

Most Class A (50 kW, non-directional day & night) AM broadcast
stations use a monopole of about 195 degrees in height, as this
extends the groundwave coverage radius over that of a 90 degree
monopole without generating a substantial high-angle lobe to interfere
with the groundwave where it otherwise would have a useful value.

Where substantial skywave signals are present from a ~195 degree
radiator, the groundwave already has been attenuated by propagation
loss to a low and nearly unusable value. This increases the distance
to the fading zone, and reduces its width.

This, too, is from the research of RCA's George Brown of BL&E fame, as
a result of his investigation and correction in 1935 of a serious
amount of nighttime fading from a ~225 degree monopole used by 50 kW
WCAU in Philadelphia.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

Earlier I wrote:
I'm not considering that the ground wave signal _provides_ any of that
low-angle DX coverage. It is the direct radiation existing in the
radiation pattern of the monopole at low elevation angles that can do
so.

.... and as a postscript --

Even though in most cases amateurs don't care about the ground wave
from a vertical monopole, a lesson can be taken from the broadcast
community in that maximizing the radiation from a monopole at angles
less than ten degrees will maximize the distance to the single-hop
coverage radius (other things equal).

This can be done by using a vertical monopole greater than 1/4-wave in
electrical height. A 5/8-wave vertical provides the highest gain in
that elevation sector.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 03:28:23 -0800 (PST), Richard Fry
wrote:

Radiation from the monopole from zero to 10 degree elevation is not
"poorer by 12 dB" than that launched at 40 degrees. It is greater.

This is the suggestion of your own supplied graphic. I thought it
rather obtuse as a topic of introduction too.

The _reception_ of such radiation is a different matter, as the total,
skywave path length, and therefore the propagation losses are
different for those elevation sectors.

And yet you discount that as an NEC analysis, strange. All far-fields
are taken from the perspective of distance.

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 04:09:34 -0800 (PST), Richard Fry
wrote:

On Nov 30, 6:27*pm, Richard Clark wrote:
However, resourcing the top engineers of the AM field for their
observations of sky-wave and ground-wave field strengths (a typical
service application) where they combine destructively (the "fading
wall"); at a distance of 70 miles, for 50% of the time, both signals
are equal (with propagation variations of phase accounting for
fading).
__________

With more research you'll find that the fading zone is not located a
fixed 70 miles away from every AM station.

Laport is authority enough for an instance for me. His data drawn
from field experience supports my model employing your reference which
responds to your complaint:
NEC far-field analysis this would seem impossible,
due to the greatly reduced fields in this sector
a statement that lacks quantifiables, and against which Laport's
example and my model only vary by 0.7 dB.

As I have asked in the past, what are your expectations for the
accuracy you expect? If it is tighter than 1dB (something exceedingly
difficult to accurately measure in the field for an absolute), then
that has been demonstrated. If it is tighter than that, your
expectations exceed the capacity of the equipment of that era that
established the FCC groundwave charts.

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 10:11*am, Richard Clark wrote:
On Mon, 1 Dec 2008 03:28:23 -0800 (PST), Richard Fry
The _reception_ of such radiation is a different matter, as the total,
skywave path length, and therefore the propagation losses are
different for those elevation sectors.

And yet you discount that as an NEC analysis, strange. *All far-fields
are taken from the perspective of distance.
____________

Far-field NEC analysis does not consider propagation loss for a
skywave and its reflection from the ionosphere.

Terman's Fig 55 does that, as well as to include earth curvature in
such loss figures.

//

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 10:21*am, Richard Clark wrote:
As I have asked in the past, what are your expectations for the
accuracy you expect? *If it is tighter than 1dB (something exceedingly
difficult to accurately measure in the field for an absolute), then
that has been demonstrated.
_________

If you can truly get within 1 dB of the FCC curves with your NEC model
in the AM broadcast band then that's good enough for me. Probably not
good enough for the FCC, though.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 10:21*am, Richard Clark wrote:
On Mon, 1 Dec 2008 04:09:34 -0800 (PST), Richard Fry
With more research you'll find that the fading zone is not located a
fixed 70 miles away from every AM station.

Laport is authority enough for an instance for me. *His data drawn
from field experience supports my model...
_______

And supporting my statement about the location of the fade zone not
being a fixed 70 miles from a monopole, note this quote starting at
the bottom of page 103 of that text applying to Laport's Fig 2.7 (your
cited authority):

"For a 190 degree radiator, the fields are not shown because it is
known immediately from the chart thus far computed that the signal
will be severely noise-limited before arriving at the distance where
fading is objectionable."

As Laport wrote his book Radio Antenna Engineering in 1952, he would
have been working from the advantage of the research and discoveries
of George Brown about this subject some 23 years earlier.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 08:52:58 -0800 (PST), Richard Fry
wrote:

Far-field NEC analysis does not consider propagation loss for a
skywave and its reflection from the ionosphere.

Terman's Fig 55 does that, as well as to include earth curvature in
such loss figures.

And this is relative to what?

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 09:45:28 -0800 (PST), Richard Fry
wrote:

And supporting my statement about the location of the fade zone not
being a fixed 70 miles from a monopole, note this quote starting at
the bottom of page 103 of that text applying to Laport's Fig 2.7 (your
cited authority):

Laport says much more than that about the fading wall. It took only
his one instance to correlate his chart to your chart and to my model
to give me pause to wonder what you are griping about when you
complain:
...NEC far-field analysis this would seem impossible,
due to the greatly reduced fields in this sector ....
a statement that lacks quantifiables. "Impossible" is
yellow-journalism fluff and the less than 1dB variations is within the
accumulation of field errors of the "possible" that went into
engineering reports. "Impossible" and "possible" are, to all intents
and purposes, describing the same thing.

What is it that is impossible? Or is this about seeming?

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 12:25*pm, Richard Clark wrote:

And this is relative to what?

To my post saying:

On Mon, 1 Dec 2008 04:09:34 -0800 (PST), Richard Fry
With more research you'll find that the fading zone is not located a
fixed 70 miles away from every AM station.

followed by your post saying:

And yet you discount that as an NEC analysis, strange. All far-fields
are taken from the perspective of distance.

You're not following.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 11:10:50 -0800 (PST), Richard Fry
wrote:

On Dec 1, 12:25*pm, Richard Clark wrote:

And this is relative to what?

To my post saying:

On Mon, 1 Dec 2008 04:09:34 -0800 (PST), Richard Fry
With more research you'll find that the fading zone is not located a
fixed 70 miles away from every AM station.

followed by your post saying:

And yet you discount that as an NEC analysis, strange. All far-fields
are taken from the perspective of distance.

You're not following.

And this is relative to what?

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 12:38*pm, Richard Clark wrote in
response to my quote below:

Below is a link to a clip from Terman's Radio Engineers Handbook, 1st
edition, showing that the greatest single-hop range for skywave
signals occurs from the radiation of the monopole at elevation angles
of less than ten degrees. But looking at a NEC far-field analysis
this would seem impossible, due to the greatly reduced fields in this
sector that NEC shows for a vertical monopole over real earth.

What is it that is impossible? Or is this about seeming?
__________

1. A far-field NEC analysis of the elevation radiation pattern of a
monopole over real earth shows little to no relative field below 10
degrees elevation. No doubt that is true of your NEC model under
discussion here, is it not?

2. Terman's Fig 55, and the experience and field measurements of AM
broadcast stations for many decades shows that there is _considerable_
radiation launched in this sector. In fact for monopoles of 5/8 wave
and less the radiated field is maximum in the horizontal plane.

How would you characterize the discrepancy existing between items 1
and 2 above?

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 1:22*pm, Richard Clark wrote:

And this is relative to what?

And this is relative to what?
_______

Juvenile.

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 11:40:06 -0800 (PST), Richard Fry
wrote:

1. A far-field NEC analysis of the elevation radiation pattern of a
monopole over real earth shows little to no relative field below 10
degrees elevation. No doubt that is true of your NEC model under
discussion here, is it not?

I see that this question bears on my previous correspondence where you
have failed to attend to that relevance. In fact, my model's 1°
response is only 1.6dB below the peak response at 8° (both of which
are below 10°). That peak response is roughly half a dB below a
perfect ground response at 0°.

I will again repeat two questions that seem to plague you to the point
of silence in their regard:

1.
What is the relevance of your side topic? Please answer it within
that side thread where I raise this question.

2.
...NEC far-field analysis this would seem impossible,
due to the greatly reduced fields in this sector ....
your statement lacks quantifiables. "Impossible" is
yellow-journalism fluff and the less than 1dB variations I have
reported are within the accumulation of field errors of the "possible"
that went into engineering reports. "Impossible" and "possible" are,
to all intents and purposes, describing the same thing.

What is it that is impossible? Or is this about seeming?

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

"Richard Clark" wrote
On Mon, 1 Dec 2008 11:40:06 -0800 (PST), Richard Fry wrote:

1. A far-field NEC analysis of the elevation radiation pattern of a
monopole over real earth shows little to no relative field below 10
degrees elevation. No doubt that is true of your NEC model under
discussion here, is it not?

I see that this question bears on my previous correspondence where
you have failed to attend to that relevance. In fact, my model's 1°
response is only 1.6dB below the peak response at 8° (both of which
are below 10°). That peak response is roughly half a dB below a
perfect ground response at 0°.
_______

Then your NEC analysis is not a _FAR-FIELD_ NEC analysis, as
repeatedly I have referenced in my posts, and even as is shown in your
quote of the same point, above.

I suggest you carefully read and consider what I write as many times
as is necessary in order to avoid such gaffes.

The rest of your post of the date/time quoted above I will dismiss, as
I have already responded to it.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Mon, 1 Dec 2008 15:24:30 -0800 (PST), Richard Fry
wrote:

Then your NEC analysis is not a _FAR-FIELD_ NEC analysis, as
repeatedly I have referenced in my posts, and even as is shown in your
quote of the same point, above.

So, how do we parse your reply? I see the assertion from you
no relative field below 10 degrees elevation.
I see from me
my model's 1° response is only 1.6dB below
the peak response at 8° (both of which are below 10°).
That peak response is roughly half a dB below a
perfect ground response at 0°.

To the greater part of the community in this group, the difference
between
no relative field below 10 degrees elevation.
and roughly half a dB below perfect at 8° elevation (which qualifies
as below 10° elevation) would leave us to believe you equate
no relative field = a field at 0.6dB below perfect
Unless, of course, you care to ammend this with quantifiables of your
own.

This portends you cannot answer for your assertion:
...NEC far-field analysis this would seem impossible,
due to the greatly reduced fields in this sector ....
your statement (now statements) lacks quantifiables. "Impossible" is
yellow-journalism fluff and the less than 1dB variations I have
reported are within the accumulation of field errors of the "possible"
that went into engineering reports. "Impossible" and "possible" are,
to all intents and purposes, describing the same thing.

What is it that is impossible? Or is this about seeming?

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

Richard Fry wrote:

...
Juvenile.

Richard Fry, meet Richard Clark ... I warned you silly-grin

Regards,
JS

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

Richard Clark wrote:

...
What is it that is impossible? Or is this about seeming?

73's
Richard Clark, KB7QHC

So then, you found "another one." And, when his energy runs out, when
he is done with you, you will still be posting your "last man standing
cr*p" ... (Cecil mentioned that--I caught on)

How impressive ... men have known you, men have argued with you, men
have debated you ... men have found you a fool ... yawn

Go back to your cave troll, await the next, he will eventually tire of
you ... double-yawn

You waste our efforts ...

Regards,
JS

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Dec 1, 8:00*pm, John Smith wrote:
Richard Clark wrote:
...
What is it that is impossible? *Or is this about seeming?

73's
Richard Clark, KB7QHC

So then, you found "another one." *And, when his energy runs out, when
he is done with you, you will still be posting your "last man standing
cr*p" ... (Cecil mentioned that--I caught on)

How impressive ... men have known you, men have argued with you, men
have debated you ... men have found you a fool ... yawn

Go back to your cave troll, await the next, he will eventually tire of
you ... double-yawn

You waste our efforts ...

Regards,
JS

No John they are like souls, looking for some body to talk to,
Looking for some body to argue with,Looking for somebody to fraternise
with.
Leave them alone as they are so happy at this time making friendly
fools of each other
like the chant of two natives bouncing around a wood fire banging two
sticks together.
While they are slapping each other like guys like kb9...... can write
in peace knowing that for
the moment they are safe. Personaly I am happy that they have found
each other thus
leaving others alone for cordial conversations and debate without the
concern of seeing
a foot suddenly appear from the next cubical. Soon the whistle will
blow when they both
have to retreat to the nursery to have their diapers changed.
It is going to take RF a long time to determine what he is dealing
with and Richard is
not likely to let go with out a fight
Sad Sad Sad but funny at the same time

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

Art Unwin wrote:

...
No John they are like souls, looking for some body to talk to,
Looking for some body to argue with,Looking for somebody to fraternise
with.
Leave them alone as they are so happy at this time making friendly
fools of each other
like the chant of two natives bouncing around a wood fire banging two
sticks together.
While they are slapping each other like guys like kb9...... can write
in peace knowing that for
the moment they are safe. Personaly I am happy that they have found
each other thus
leaving others alone for cordial conversations and debate without the
concern of seeing
a foot suddenly appear from the next cubical. Soon the whistle will
blow when they both
have to retreat to the nursery to have their diapers changed.
It is going to take RF a long time to determine what he is dealing
with and Richard is
not likely to let go with out a fight
Sad Sad Sad but funny at the same time

Art:

I will not lie to you, I have a hard time following you. Sometimes I
even doubt your sanity, your grounds on which you make your statements,
very often, evade me--however, you have never neared the "fool status" I
place the "reciter of Shakespeare" in (read this as Richard Clark!) ...
you at least bring me areas I wonder about and do not sound so foolish
.... :-)

Regards,
JS

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

"Richard Clark" wrote in message
On Mon, 1 Dec 2008 15:24:30 -0800 (PST), Richard Fry wrote:

Then your NEC analysis is not a _FAR-FIELD_ NEC analysis, as
repeatedly I have referenced in my posts, and even as is shown in your
quote of the same point, above.

So, how do we parse your reply? (ad nauseum).
____________

It is clear that your interest in this thread has turned to playing
word games.

But not with me, anymore.

RF

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

On Tue, 2 Dec 2008 02:54:09 -0800 (PST), Richard Fry
wrote:

It is clear that your interest in this thread has turned to playing
word games.

This confirms my earlier observation that you had no support for one
rather meek word game from you:
...NEC far-field analysis this would seem impossible,
due to the greatly reduced fields in this sector ....
your statement (now statements) lacks quantifiables. "Impossible" is
yellow-journalism fluff and the less than 1dB variations I have
reported are within the accumulation of field errors of the "possible"
that went into engineering reports. "Impossible" and "possible" are,
to all intents and purposes, describing the same thing.

What is it that is impossible? Or is this about seeming?

If you cannot support your own statements with quantifiables, I can
see why you shy from further pale elaboration.

73's
Richard Clark, KB7QHC

Low-angle Elevation Gain of a 1/4-wave Vertical Monopole
 

Richard Fry wrote:

...
It is clear that your interest in this thread has turned to playing
word games.

But not with me, anymore.

RF

Yes, exactly! He is like that, yanno? wink

Regards,
JS