Lets assume a single hop 40m signal from 400 miles away. What
elevation angle does it arrive at? Both stations are using inverted V's
at nominal height. There are no large bodies of water in between.

Daytime and/or nighttime.

--
73's de Ken KG0WX - Kadiddlehopper #11808,
Flying Pigs #-1055, Grid EM17io, TS-850SAT,
Elecraft XG2, 4SQRP Tenna Dipper, Heath GD-1B

"Ken Bessler" wrote in message
news:VEmag.22577$4H.10017@dukeread03...
Lets assume a single hop 40m signal from 400 miles away. What
elevation angle does it arrive at? Both stations are using inverted V's
at nominal height. There are no large bodies of water in between.

Daytime and/or nighttime.

--
73's de Ken KG0WX -

depends on the height of the reflecting/refracting layer, time of day,
sunspot number and associated geometry. Intensity of signals will depend on
how the radiation angle - pattern of the antennas fits the propagation
angles.
There are some propagation programs that will provide good answers based on
above data.

Yuri, K3BU

"Ken Bessler" wrote in message
news:VEmag.22577$4H.10017@dukeread03...
Lets assume a single hop 40m signal from 400 miles away. What
elevation angle does it arrive at? Both stations are using inverted
V's
at nominal height. There are no large bodies of water in between.

Daytime and/or nighttime.

--
73's de Ken KG0WX
===================================

The type of antenna or its radiation pattern has nothing whatever to
do with the path taken by the radio wave through the ionosphere. The
take-off angle and its name, generated by EZNEC, can be very
misleading.

The radio path is simply a matter of trigonometry involving only the
groundpath distance between transmitter and receiver and the height of
the reflecting layer.

The height of the reflecting layer changes between day and night. And
there may be more than one layer present in daylight. The layer
actually used depends on frequency.

If the Tx and Rx stations are far apart, the trigonometry becomes a
little bit complicated because of the curvature of the Earth's
surface. But for groundpath distances up to 500 miles a flat earth can
be assumed. Get a sheet of paper and a pencil and sketch the triangle
to be solved. The average height of the F-Layer in darkness is about
200 miles. In daylight it is about 300 miles.

To do the actual calculations download program SKYTRIG from website
below in a few seconds and run immediately. SKYTRIG is near the bottom
of the list on the "Download Progs From Here" page. Just left-click
on it.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........

Reg Edwards wrote:
"Ken Bessler" wrote in message
news:VEmag.22577$4H.10017@dukeread03...

Lets assume a single hop 40m signal from 400 miles away. What
elevation angle does it arrive at? Both stations are using inverted

V's

at nominal height. There are no large bodies of water in between.

Daytime and/or nighttime.

--
73's de Ken KG0WX

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

The type of antenna or its radiation pattern has nothing whatever to
do with the path taken by the radio wave through the ionosphere. The
take-off angle and its name, generated by EZNEC, can be very
misleading.

It is hard to look at a radiation pattern, conclude that the take-off
angle is the only angle of radiation, and then blame it on EZNEC! Most
of the antennas that I have modeled seem to have radiation in lots of
directions. 8^) Otherwise you are correct.



The radio path is simply a matter of trigonometry involving only the
groundpath distance between transmitter and receiver and the height of
the reflecting layer.

The height of the reflecting layer changes between day and night. And
there may be more than one layer present in daylight. The layer
actually used depends on frequency.

If the Tx and Rx stations are far apart, the trigonometry becomes a
little bit complicated because of the curvature of the Earth's
surface. But for groundpath distances up to 500 miles a flat earth can
be assumed. Get a sheet of paper and a pencil and sketch the triangle
to be solved. The average height of the F-Layer in darkness is about
200 miles. In daylight it is about 300 miles.

To do the actual calculations download program SKYTRIG from website
below in a few seconds and run immediately. SKYTRIG is near the bottom
of the list on the "Download Progs From Here" page. Just left-click
on it.


- 73 de Mike KB3EIA -

Mike Coslo wrote:
It is hard to look at a radiation pattern, conclude that the
take-off angle is the only angle of radiation, and then blame it on
EZNEC!

I knew a ham in Chandler, AZ who would adjust not only
the direction but the height of his beam for maximum signal.
I assume by adjusting the height, he was changing his TOA.
--
73, Cecil http://www.qsl.net/w5dxp

On Wed, 17 May 2006 13:30:31 GMT, Cecil Moore
wrote:

Mike Coslo wrote:
It is hard to look at a radiation pattern, conclude that the
take-off angle is the only angle of radiation, and then blame it on
EZNEC!

I knew a ham in Chandler, AZ who would adjust not only
the direction but the height of his beam for maximum signal.
I assume by adjusting the height, he was changing his TOA.


I have heard of many hams stacking beams vertically to get that
earlier signal on one beam, and later in the day, the other beam gets
the stronger signal. Together, they still amplify the signal, but
sometimes one does much better than others at the TOA.


--
73 for now
Buck
N4PGW

Reg wrote:
The type of antenna or its radiation pattern has nothing whatever to
do with the path taken by the radio wave through the ionosphere. The
take-off angle and its name, generated by EZNEC, can be very
misleading.


It has to do. It allows us to direct the RF under desired angle to hit the
layer or region that supports the propagation to the chosen target.
I have seen situations when signals to Europe were coming under low angle
and in the same direction, signals to deep Asia were coming under higher
angle at the same time.

There are different propagation modes and paths and be able to control
radiation pattern of antenna is important (for serious hams, like
contesters). I am not talking about skewed path, long path and other modes
of propagation when horizontal and vertical control of the antenna radiation
pattern is of huge benefit.

So making blank statements like above is not proper.

73 Yuri K3BU

"Yuri Blanarovich" wrote in message
...
Reg wrote:
The type of antenna or its radiation pattern has nothing whatever
to
do with the path taken by the radio wave through the ionosphere.
The
take-off angle and its name, generated by EZNEC, can be very
misleading.


It has to do. It allows us to direct the RF under desired angle to
hit the
layer or region that supports the propagation to the chosen target.
=======================================
Yuri,

But you can't "direct" it.

You have to do your best with whatever elevation angle Eznec dictates.
----
Reg.

"Reg Edwards" wrote in message
...

"Yuri Blanarovich" wrote in message
...
Reg wrote:
The type of antenna or its radiation pattern has nothing whatever
to
do with the path taken by the radio wave through the ionosphere.
The
take-off angle and its name, generated by EZNEC, can be very
misleading.


It has to do. It allows us to direct the RF under desired angle to
hit the
layer or region that supports the propagation to the chosen target.
=======================================
Yuri,

But you can't "direct" it.

You have to do your best with whatever elevation angle Eznec dictates.
----
Reg.


You bet I can, I can do that with stacked antennas, rotatable, polarization
switchable, phasing, crank up tower changing height antennas - and by what
antenna design and surroundings dictate, not EZNEC. EZNEC gives approximate
picture of radiation pattern produced by antenna model. Real life (ground
conditions, surroundings) changes the antenna pattern.
So I would be carefull giving EZNEC absolute powers dictating anything :-)
Combined with terrain analysis software, it will give better picture of
where the antenna projects the signal.

73 Yuri, K3BU

Yuri Blanarovich wrote:
I have seen situations when signals to Europe were coming under low angle
and in the same direction, signals to deep Asia were coming under higher
angle at the same time.

Seems to me a rotatable dipole with the ability to also
rotate from horizontal to vertical would be a good thing
to have.
--
73, Cecil http://www.qsl.net/w5dxp