DXView Gray-Line


Rick Arzadon - N8XI
 
Edited

When I enter these calls YO9HP, 5T5PA, KL7YK, EA5UI, DL6LAG & OS0S I have no GL Path(s).
Entering PY2GIG, CX8FB & SM2EKM GL Paths seem to be OK.

These Calls are from DXKeeper.

Entering just KL7 I had Sunrise GL starting (First Row) 2020-06-14 09:25 Ending (14th Row) 2020-06-27 09:25

(Last Row) starting 2020-06-27 09:28 ending 09:30

Thanks

Rick - N8XI


Dave AA6YQ
 

+ AA6YQ comments below

When I enter these calls YO9HP, 5T5PA, KL7YK, EA5UI, DL6LAG & OS0S I have no GL Path(s).
Entering PY2GIG, CX8FB & SM2EKM GL Paths seem to be OK.

These Calls are from DXKeeper.

Entering just KL7 I had Sunrise GL starting (First Row) 2020-06-14 09:25 Ending 09:25

(Last Row) starting 2020-06-27 09:28 ending 09:30

+ That's correct, Rick. There are many locations on the planet to which there will never be a gray-line path from your QTH.

+ To see this, use the "Solar position" panel on the "World Map" tab of DXView's Configuration window to see where the terminator lies during each month of the year, fine-tuning the terminator position by adjusting the hour.

+ It would be an interesting exercise to develop an application that checks every grid square for the existence of gray-line paths from your QTH at some time during the year, identifying those grid squares from which there is never a gray-line opening. I have no intuition as to the "shape" those grid squares would create.

73,

Dave, AA6YQ


Rick Arzadon - N8XI
 

Thanks Dave learned something new...to me


ghassan chammas
 

What is a gray line propagation? Why is this gray line important between 2 points in as far as radio communication is concerned?
How do you use it to transmit? You put your yagi tangeant to the line?
Can you point out to any substantialbarticle to read more about it?

Many thanks
Ghassan 
Od5ya



Sent from Samsung tablet.

-------- Original message --------
From: "Rick Arzadon - N8XI via Groups.Io" <n8xi_1@...>
Date: 13/07/2019 05:33 (GMT+02:00)
To: DXLab@groups.io
Subject: Re: [DXLab] DXView Gray-Line

Thanks Dave learned something new...to me


Jim Wysocki
 

Ghassan, others can give a more technical explanation, but from the view of a typical DXer, here are some details.  The greyline is the transition period from sunlight to darkness, or from darkness to sunlight.  During this period, which can last for many minutes, radio signals can more easily propagate over long distances.  This of course makes possible short QSOs between two places that, under more typical circumstances, would not be able to take place.  Because the earth's axis tilts over the course of the year, the greyline shifts, within certain limits, plus or minus 15 degrees or so East and West.

This means that at certain times of the year a propagation path between two locations will be open when it otherwise never would be.  If you and a rare DX location share a path, you'll have a better chance at making a QSO.  That's why people who want to maximize their chances of getting a particular rare station pay attention to greyline conditions.

That's an oversimplified explanation of greyline propagation.  I hope that it helps you a bit.

73,  Jim  W9FI

On 7/13/2019 8:15 AM, ghassan chammas via Groups.Io wrote:
What is a gray line propagation? Why is this gray line important between 2 points in as far as radio communication is concerned?
How do you use it to transmit? You put your yagi tangeant to the line?
Can you point out to any substantialbarticle to read more about it?

Many thanks
Ghassan
Od5ya



Sent from Samsung tablet.

-------- Original message --------
From: "Rick Arzadon - N8XI via Groups.Io" <n8xi_1=yahoo.com@groups.io>
Date: 13/07/2019 05:33 (GMT+02:00)
To: DXLab@groups.io
Subject: Re: [DXLab] DXView Gray-Line

Thanks Dave learned something new...to me


Larry Knain
 

On 40, 80, and 160 you can get propagation along the "gray line" - the line between day and night. If you can, see ON4UN's book on Low Band DX'ing.

From the East coast of the US to the West coast of Australia about the only time we can make QSOs on 160 is along the gray line and it runs more or less about 15 minutes centered on our sunrise (US).

73, Larry W6NWS

On 7/13/2019 11:15 AM, ghassan chammas via Groups.Io wrote:
What is a gray line propagation? Why is this gray line important between 2 points in as far as radio communication is concerned?
How do you use it to transmit? You put your yagi tangeant to the line?
Can you point out to any substantialbarticle to read more about it?

Many thanks
Ghassan 
Od5ya



Sent from Samsung tablet.

-------- Original message --------
From: "Rick Arzadon - N8XI via Groups.Io" <n8xi_1@...>
Date: 13/07/2019 05:33 (GMT+02:00)
Subject: Re: [DXLab] DXView Gray-Line

Thanks Dave learned something new...to me


w6de
 

Do a Google search on ‘gray line propagation and there are a number of explanations from the simple to technical.  Here is the one I like best:

The "grey line" is a band around the Earth that separates daylight from darkness. Propagation along the grey line is very efficient. One major reason for this is that the D layer, which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side.

 

Dave, w6de

 

From: DXLab@groups.io [mailto:DXLab@groups.io] On Behalf Of ghassan chammas via Groups.Io
Sent: 13 July, 2019 15:15
To: DXLab@groups.io
Subject: Re: [DXLab] DXView Gray-Line

 

What is a gray line propagation? Why is this gray line important between 2 points in as far as radio communication is concerned?

How do you use it to transmit? You put your yagi tangeant to the line?

Can you point out to any substantialbarticle to read more about it?

 

Many thanks

Ghassan 

Od5ya

 

 

 

Sent from Samsung tablet.

 

-------- Original message --------

From: "Rick Arzadon - N8XI via Groups.Io" <n8xi_1@...>

Date: 13/07/2019 05:33 (GMT+02:00)

To: DXLab@groups.io

Subject: Re: [DXLab] DXView Gray-Line

 

Thanks Dave learned something new...to me


ghassan chammas
 

It does.thank youbso much
Od5ya
Ghassan



Sent from Samsung tablet.

-------- Original message --------
From: Jim Wysocki <wysocki1@...>
Date: 13/07/2019 18:33 (GMT+02:00)
To: DXLab@groups.io
Subject: Re: [DXLab] DXView Gray-Line

Ghassan, others can give a more technical explanation, but from the view
of a typical DXer, here are some details.  The greyline is the
transition period from sunlight to darkness, or from darkness to
sunlight.  During this period, which can last for many minutes, radio
signals can more easily propagate over long distances.  This of course
makes possible short QSOs between two places that, under more typical
circumstances, would not be able to take place.  Because the earth's
axis tilts over the course of the year, the greyline shifts, within
certain limits, plus or minus 15 degrees or so East and West.

This means that at certain times of the year a propagation path between
two locations will be open when it otherwise never would be.  If you and
a rare DX location share a path, you'll have a better chance at making a
QSO.  That's why people who want to maximize their chances of getting a
particular rare station pay attention to greyline conditions.

That's an oversimplified explanation of greyline propagation.  I hope
that it helps you a bit.

73,  Jim  W9FI

On 7/13/2019 8:15 AM, ghassan chammas via Groups.Io wrote:
> What is a gray line propagation? Why is this gray line important
> between 2 points in as far as radio communication is concerned?
> How do you use it to transmit? You put your yagi tangeant to the line?
> Can you point out to any substantialbarticle to read more about it?
>
> Many thanks
> Ghassan
> Od5ya
>
>
>
> Sent from Samsung tablet.
>
> -------- Original message --------
> From: "Rick Arzadon - N8XI via Groups.Io" <n8xi_1@...>
> Date: 13/07/2019 05:33 (GMT+02:00)
> To: DXLab@groups.io
> Subject: Re: [DXLab] DXView Gray-Line
>
> Thanks Dave learned something new...to me
>




Rick Arzadon - N8XI
 

Dave, W6DE That last sentence explains alot...Thanks!

73,  Rick - N8XI