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Here's another plot for FR5ZX decodes showing
Thursday / Friday night. Nice to see even more stations making it to La
Reunion!
Generally I would agree with Alan that low-angle
ground reflections from a planar dielectric surface (sand) may be nearly as
effective as from a conductor (salt water), and that on the other hand
scattering off mountain ranges may significantly hinder or interrupt long-range
propagation. However the Sahara is not really all flat...
Yesterday night propagation appeared to be weaker
and short-lived - only 18 spots alltogether and the last one at 22:46 UT.
Coronal mass ejection arrived on earth?
All the best,
Markus
Sent: Friday, November 06, 2015 1:54 AM
Subject: Re: LF: Re: FR5ZX WSPR again
Hi
Stefan yes it's interesting because there has be steady low level
geomagnetic storms since the 3rd at Kp=5. I am wondering if what we
are
seeing is more a feature of a predominantly N<>S path rather than
the more
usual long, predominantly E<>W paths to Joe and Alex. I
suppose crossing the
Equator there is much less effect from precipitated
electrons which happens
mainly at, or near, the poles.
An interesting
way of analysing the 9000km path would be to cut it into 4
hops and see
where the ground interaction takes place. (it is roughly 2000
to 2500km per
hop) I do wonder if the desert (quartz) might have a similar
effect to sea.
(the desert sand was given as one reason why the "Poynting
vector" aerials
seemed to give good results in Egypt)
The signal doesnt really "bounce"
if you draw the profile accurately it
approached the ground at near zero
degrees. I have a feeling that the long
distance signal may be more affected
by the ground "roughness"
(scattering??) at mid-path than the
resistivity/permiability. In fact most
of the signal just skims the ground.
There is no doubt the sea effect is
certainly clear at the path ends.
There was some suggestion of preferential
N<>S paths between ZL and
Asia, but strangely it was never as good to
W.Coast/Alaska or
Honalulu.
What is surprising is that there are not similar paths to South
America from
Europe. However the question is then " is anyone monitoring".
Likewise to
RSA but I believe LF is not popular with amateurs in
ZS.
It will be interesting to see what happens when the CME arrives
overnight on
the 7th. It may not affect the path to La Reunion until the
night of 7/8.
I noticed a set of regular 4min interval decodes then a 16
min blank which I
presume must have been a fade. Also your best reception
was soon after the
fade I think??
Fascinating stuff this LF/MF
propagation :-))
Alan
G3NYK
----- Original Message
-----
From: "DK7FC" <[email protected]>
To:
<[email protected]>
Sent:
Thursday, November 05, 2015 11:54 PM
Subject: Re: LF: Re: FR5ZX WSPR
again
> Attached is a picture showing the path for EA5DOM. So far
i thought that
> the red sea is supporting the path for stations from DL,
PA, SV and I,
> allowing one or 2 hops on sea water. But now Luis' path is
directly over
> Africa.
> Hmmmm, Alan? Any thoughts?
:-)
>
> 73, Stefan
>
> Am 05.11.2015 23:59, schrieb
VIGILANT Luis Fernández:
>> Wops !!
>>
>>
2015-11-05 22:48 EA5DOM 0.475790 -20 0 IM98wn 0.05 FR5ZX LG78pu
8796
>>
>> New coil ! Antenna is finally on resonance
..... and seems to work ! ;-)
>>
>> 73 de Luis
>>
EA5DOM
>
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