Thanks for that Jay I will factor that into my musings :-))
I think that is within the range I have been considering.....so that is
very useful data.
You put the finger on the difficulty of knowing how much the local noise
level has shifted, but this is where your long experience is an advantage.
I have a vast amount of data the problem is thinking of a way of displaying
it that will stimulate some new ideas.....plenty to fill my waking hours
:-))
Alan
G3NYK
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Wednesday, February 20, 2013 3:01 PM
Subject: Re: LF: Beacon to the west
Alan
Thanks for your comments.
Based on Spectrum Lab's s/n measurement, along with that of WSPR, I would
say that we are in a period where signals are down roughly 6 - 10 dB on
the EU > NA T/A path as compared to a month ago. There have been a few
nights where the noise floor was elevated due to thunderstorms in the US
but I am not including them in my observation.
Jay W1VD WD2XNS WE2XGR/2
p.s. I rarely use Argo any more since it is virtually impossible to
determine s/n of the received signals.
----- Original Message -----
From: "Alan Melia" <[email protected]>
To: <[email protected]>
Sent: Wednesday, February 20, 2013 9:32 AM
Subject: Re: LF: Beacon to the west
Hi Jay I am still pondering this, plotting Dst against "period receive
signal exceeds xdB" gives a interesting but not very illumination
picture. It provides a cut off when theDstis depressed, but it shows a
wide range of received signals when the Dst is high (towards zero nT). I
am still looking for another factor.
By "quiet period" I mean Kp <2 for 10 days or more.... really quiet
geomagnetically and signal levels seem to be unexpectedly poor. Then
signals seem to improve after a low level event say Kp=4 . That led to my
idea of ionospheric "leak".
However taking a quick look at the recent conditions, things look active
enough to be "normal". It is very confusing but I am looking to see if it
could be explained by just an unfavourable path length/fading.
Unfortunately one needs several stations in different location to either
tranmit, or several receiving stations to receive the same signal to see
the effect of this. If some paths are unfavouable other should be
favoured.
One problem also is I do not know what a "subjectively" worse signal
means, does it mean 10dB ?? Most likely not waterfal displays are very
non-linear so it might only be a dB or two. That could easily be expained
by a fading pattern involving say three different hop modes.
There was a grab recently that shoed Stefan and Markus. Markus was fading
to a "ragged" trace at times whereas Stefan was solid all the time,
though they were probably seeing similar fading conditions.
I am still not convinced that there is not some other effect but I cant
find anything:-)) Bit like "Dark Propagation" :-))
Best Wishes
Alan
G3NYK
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Cc: <[email protected]>; <[email protected]>
Sent: Wednesday, February 20, 2013 12:38 PM
Subject: Re: LF: Beacon to the west
Stefan
Good copy last night ... although some dB short of the 'best'
conditions. Seem to recall Alan mentioning that prolonged 'quiet'
periods can be less favorable than those that feature some 'ups and
downs'. Maybe Alan will chime in.
Representative capture below. Copy past 0800Z at
http://www.w1vd.com/interestinggrab.html ... if you squint hard enough.
Jay W1VD WD2XNS WE2XGR/2
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