Yes that's the problem Jim, from this side, Mal's over the hill ...
I can acquire mf-2 lock with round 35/50 watts carrier power
during
the day to John, but need round 150/180 for the path to Delft
Unfortunately , I think , due to Ae modifications this qth , my Rx
noise level is very high to the point of reducing Rx s/n
considerably . so any comparisons are marred at the moment
Last night it was not till nearly midnight , I decoded John's wspr
tx beacon ..
2011-09-02 23:42 GM4SLV 0.503859 -26 0 IP90gg 0.5 G0NBD
IO83lk 766 188
2011-09-02 23:32 GM4SLV 0.503869 -24 0 IP90gg 0.5 G0NBD
IO83lk 766 188
Yes nothing during these decodes , 25 miles to my east , unless
there is fringing
at play ?
2011-09-02 22:46 GM4SLV 0.503852 -8 0 IP90gg 0.5 G4WGT
IO83qo 745 186
2011-09-02 22:34 GM4SLV 0.503852 -16 0 IP90gg 0.5 G4WGT
IO83qo 745 186
--------------------------------------------------
From: "James Moritz" <[email protected]>
Sent: Saturday, September 03, 2011 5:33 PM
To: <[email protected]>
Subject: LF: Re: 500 Khz - QSO
Dear John, LF Group,
Good signals in daytime - steady with little QSB, but some QRN just
starting to build. The sea-path down the East Coast must help
enormously!
Looking at the map, the path Shetland - Scarborough is almost entirely
over the sea, while Shetland - Lancashire/Cheshire is about 50% over the
rocky ground of Scotland and NW England. Looking at the ITU ground loss
curves for 500kHz, and applying the "Millington Method" for the
appropriate distances and ground conductivities comes up with something
like 30dB less signal at G0NBD/G4WGT compared with G3KEV, even though the
distance is similar. This is easily enough to make the difference between
an audible signal and one that would require long integration periods on a
spectrogram to detect. It might be interesting one day for you to try
transmitting slow QRSS signals during daytime ground-wave conditions, and
see if your signals are detectable at inland and western UK locations to
make a comparison with east-coast locations.
Cheers, Jim Moritz
73 de M0BMU
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