John and group
Your 'data mining' produced some misleading results and conclusions...
There were no "super strong groundwave" reports from W stations - in
fact nothing in +ve SNR figures at all.
The best SNR for a potential Groundwave path was:
2010-10-31 01:52 WD2XSH/17 0.501090 -4 0 FN42pb 1 WE2XGR/2 FN31is 216
A mere -4dB SNR at 216km for a reported ERP of 1W - hardly bending the
needle!
The spot you site above from WE2XGR/2 was made using the westerly direction of the 1000' beverage
receive antenna. The front to back of the antenna knocked WD2XSH/17 signal down some 10 - 20 dB.
Looking at last night's data using the beverage easterly direction (EU) we get the following for
WD2XSH/17:
2010-11-05 03:10 WD2XSH/17 0.501090 +10 -1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 03:00 WD2XSH/17 0.501091 +10 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:54 WD2XSH/17 0.501090 +11 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:44 WD2XSH/17 0.501091 +10 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:36 WD2XSH/17 0.501090 +5 -1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:30 WD2XSH/17 0.501090 +7 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:22 WD2XSH/17 0.501090 +9 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:14 WD2XSH/17 0.501090 +9 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 02:08 WD2XSH/17 0.501090 +11 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 01:58 WD2XSH/17 0.501090 +11 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 01:52 WD2XSH/17 0.501091 +9 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 01:44 WD2XSH/17 0.501091 +10 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-11-05 01:36 WD2XSH/17 0.501091 +11 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-10-31 02:22 WD2XSH/17 0.501090 +4 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-10-31 02:14 WD2XSH/17 0.501090 +1 0 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
2010-10-31 02:06 WD2XSH/17 0.501091 +2 1 FN42pb +30 1.000 WE2XGR/2 FN31is 216
134
And for WD2XSH/37:
2010-11-05 03:02 WD2XSH/37 0.501099 +6 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:52 WD2XSH/37 0.501099 +7 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:46 WD2XSH/37 0.501099 +5 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:40 WD2XSH/37 0.501099 +4 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:30 WD2XSH/37 0.501099 +2 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:24 WD2XSH/37 0.501099 +4 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:14 WD2XSH/37 0.501099 +3 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:06 WD2XSH/37 0.501099 +4 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 02:00 WD2XSH/37 0.501099 +5 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 01:50 WD2XSH/37 0.501099 +8 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 01:42 WD2XSH/37 0.501099 +10 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
2010-11-05 01:34 WD2XSH/37 0.501099 +10 0 FN42fo +30 1.000 WE2XGR/2 FN31is 171
106
Signal levels were significantly above the -4 dB that you site. Several other things to consider:
this was an average night - signal levels can be significantly higher; there are more than just
these two stations active on WSPR that put in similar, or stronger, signal levels; WD2XSH/17 is
shown to be running only 1W erp at this time but he, and others, have run higher power in the past
(WD2XSH limit is 20W ERP and WE2XGR limit is 200W ERP).
Last year a number of stations using WSPR noted multiple 'phantom' spots when the decoder was
presented with one or more strong (>+10) signals in the passband. In addition, there is the
'desensing' issue which negatively impacts the reception of weak signals.
PA0A, for example, is the most consistently strong signal here and makes it across the pond much of
the time. It's the weaker stations that are only received on rare ocassions that will suffer the
most. I stick by my earlier comment that a clear shot at them will produce more and better results.
Not trying to rain on anyone's parade here ... just telling it the way it is.
Jay
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