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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