Testing was done with 2.4 KHz Bandwidth; No Noise Blanker; No Audio Processing

First test is with Crossed dipoles - 160 Windom and 80 dipole - at 32 feet AGL
Matched with an LC network for 500 KHz
S meter resting at S-9, and peaking to 20dB over
It took 4 transmissions to get 4 decodes

 0032    -14   <...> EM31JS 
 0036    -21   WD2XSH/7 
 0040   -12   <WD2XSH/7>
 0046   -12    WD2XSH/7 

Second test is with crossed dipoles straight into the radio - No Matching
S meter resting at S-4 and peaking to 5dB over at start, but the noise began
to rise quickly, and by the end of the test was at 15dB over S-9
It took 7 transmissions to get 4 decodes

 0054    -8    WD2XSH/7 
 0058    -6    <WD2XSH/7> 
 0102   -14   WD2XSH/7 
 0116   -12   <WD2XSH/7> 

Third test is with a 1750 meter - 40 foot Vertical with 10 foot Top Hat working
over 12 radials, each 32 feet long with perimeter wire.
Antenna is self resonant around 225 KHz
S meter resting at S-2 peaking to an S-8... Storm static continued to rise
rapidly during this segment
It took 6 transmissions to get 4 decodes

Note: during this segment, the band appeared to QSB at this QTH, as well
as seeing the storm static rise rapidly

 0120   -11    WD2XSH/7 
 0122   -12    <WD2XSH/7>
 0128   -16    WD2XSH/7 ( note: severe static crashes during this segment )
 0132    -4    <WD2XSH/7>
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This test was to see the difference in WSPR SNR readings with different
antenna setups..My observations were: The resonant antenna gave higher
signal levels, but also higher noise levels resulting in a lower SNR number.
The Non-Resonant antenna ( dipoles ) had lower signal levels as well as
lower noise levels that seemed to produce a higher SNR number.
My thought is; the same signal, but lower noise for WSPR to process
which shows a better Signal vs. Noise reading.
Finally, the 1750 meter Vertical seemed to produce the best SNR of
the three tests. Unfortunately the band went into QSB and was rising
at the end of test three. Continued listening showed that the band did
recover, and stayed strong afterwards
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

Fourth test is with the 1750 meter Vertical, still using 2.4 KHz Bandwidth.
Turned on the Noise Blanker, and inserted a passive audio clipper that
levels out the noise power going into the soundcard
S meter resting at S-2 and peaking to S-5.. As this test continued; the
static became viscious, and the S-meter was peaking at S-7 by 02:00 UTC

Note: Stations XSH/15 and XSH/17 were seen clearly in the waterfall display
but never decoded until turning on the audio processing.

 0138    -3    <WD2XSH/7>
 
 0142    -23   WD2XSH/15 
 0142    -6     WD2XSH/7 

 0146     0    <WD2XSH/7>

 0150    -20   WD2XSH/17 
 0150    -1     WD2XSH/7 

 0154    -24   WD2XSH/15 
 0154    -3     <WD2XSH/7> 

 0156   -20    <WD2XSH/17>
 
 0158    -6     WD2XSH/7 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

My thoughts on WSPR SNR readings is that they are relevant only to the 
station that supplied them, considering the radio, and its settings, the
antenna, and its configuration, geographical area, band conditions at the time,
and local noise levels. 2 stations on the same city block may report different
SNR numbers while receiving the same station, at the same signal level.
My observations from the four tests I did this evening is; the SNR numbers
varied noticably with each antenna setup, and in the fourth test; changing
the settings of the radio. For receive purposes; the non-resonant antenna
setup provided the lowest noise power into WSPR, and the best reception
results with more signal vs. noise..I have traditionally thought that, the
more antenna the better. While in transmit this might be the case, on
receive, in noisy conditions, " less " may be more....
Although only a crude field test; the results clearly varied with each one.

Andy - KU4XR