[Skimmertalk] Skimmer Experiance: 160M and 10M

Mon Dec 22 20:45:19 EST 2008

Hi Jamie - this is potentially a very interesting set of datapoints.  A 
couple of questions --

Can you determine, from your log, which of these is actually a case where 
you were not CQing, but worked someone S&P and were spotted by Skimmer as 
if you were CQing?  The reason I ask is this - N0XR has had a lot of 
trouble with images (that is, signals being "heard" by his softrock on both 
side of the local oscillator frequency.  Take this series:

N0XR-4 NS3T 7086.3 CQ 5 dB 26 wpm 2142z 30 Nov
N0XR-4 NS3T 7025.6 CQ 5 dB 27 wpm 2142z 30 Nov
N0XR-4 NS3T 7086.3 CQ 7 dB 27 wpm 2140z 30 Nov
N0XR-4 NS3T 7025.6 CQ 9 dB 27 wpm 2139z 30 Nov

Were you really on both of those frequencies, back and forth, within 3 
minutes?  I think it's more likely that you were on 7025.6, that N0XR 
copied you both there and on the image.  With a local oscillator frequency 
of ~7056, pretty standard for SoftRocks on 40M, the image of 7025.6 would 
be heard at 7086.3.

This series is harder to figure out:

N0XR-4 NS3T 7045.8 CQ 11 dB 27 wpm 2113z 30 Nov
N0XR-4 NS3T 7051.8 CQ 24 dB 28 wpm 2110z 30 Nov
N0XR-4 NS3T 7062.2 CQ 11 dB 29 wpm 2109z 30 Nov
N0XR-4 NS3T 7082.0 CQ 16 dB 27 wpm 2104z 30 Nov
N0XR-4 NS3T 7025.0 CQ 5 dB 29 wpm 2102z 30 Nov

7025 and 7082 could be an image pair, but the local oscillator would have 
to be 7053.5.  So could 7051.8 and 7062.5, if the local oscillator were at 
7057.

Did any of those correlate with instances when you logged QSOs that were 
either S&P or running?

I'm not poo-pooing the problem for a minute.  It is probably the most 
serious problem experienced by Skimmer users during the fall season.  It 
happens a lot, especially with weak signals in the presence of a lot of 
noise, like ARRL 160, where stations are calling repeatedly and giving 
their calls more than once.  If we can help Alex develop a set of better CQ 
validation rules for the next edition of Skimmer, I'm sure he'd be delighted.

73, Pete N4ZR

Jamie Dupree NS3T wrote:
>Dean N0XR discussed in his recent post how Skimmer was posting a lot of
>calls
>of stations who were answering CQ's, but not calling CQ.  I decided to
>check the spot search on the Reverse Beacon Project, and that's exactly
>what I found with my call from CQ WW CW when the N0XR Skimmer
>heard me.
>
>I put the entire list here.  There are a few CQ's in there from other
>Skimmers where I actually was calling, but for the most part, they
>all found me in S&P.  I send this along not to complain, but just for
>your consumption on how to ferret out S&P'ers.
>
>
>N0XR-4 NS3T 7013.4 CQ 15 dB 25 wpm 2145z 30 Nov
>N0XR-4 NS3T 7086.3 CQ 5 dB 26 wpm 2142z 30 Nov
>N0XR-4 NS3T 7025.6 CQ 5 dB 27 wpm 2142z 30 Nov
>N0XR-4 NS3T 7086.3 CQ 7 dB 27 wpm 2140z 30 Nov
>N0XR-4 NS3T 7025.6 CQ 9 dB 27 wpm 2139z 30 Nov
>N0XR-4 NS3T 7045.8 CQ 11 dB 27 wpm 2113z 30 Nov
>N0XR-4 NS3T 7051.8 CQ 24 dB 28 wpm 2110z 30 Nov
>N0XR-4 NS3T 7062.2 CQ 11 dB 29 wpm 2109z 30 Nov
>N0XR-4 NS3T 7082.0 CQ 16 dB 27 wpm 2104z 30 Nov
>N0XR-4 NS3T 7025.0 CQ 5 dB 29 wpm 2102z 30 Nov
>W0QL NS3T 14025.5 CQ 29 dB 27 wpm 1850z 30 Nov
>W0QL NS3T 14023.7 CQ 46 dB 27 wpm 1848z 30 Nov
>N0XR-2 NS3T 14065.2 CQ 23 dB 28 wpm 1824z 30 Nov
>N0XR-2 NS3T 14048.8 CQ 8 dB 30 wpm 1822z 30 Nov
>N0XR-2 NS3T 14037.8 CQ 10 dB 29 wpm 1821z 30 Nov
>N0XR-2 NS3T 14074.6 CQ 13 dB 29 wpm 1817z 30 Nov
>N5RR NS3T 14064.2 CQ 17 dB 30 wpm 1813z 30 Nov
>N5RR NS3T 14060.4 CQ 12 dB 27 wpm 1812z 30 Nov
>N0XR-2 NS3T 14027.4 CQ 14 dB 29 wpm 1811z 30 Nov
>N0XR-2 NS3T 14059.3 CQ 6 dB 28 wpm 1811z 30 Nov
>N0XR-2 NS3T 14027.4 CQ 12 dB 30 wpm 1811z 30 Nov
>N5RR NS3T 14059.5 CQ 14 dB 30 wpm 1811z 30 Nov
>N5RR NS3T 14050.6 CQ 26 dB 29 wpm 1808z 30 Nov
>N0XR-2 NS3T 14048.8 CQ 17 dB 28 wpm 1806z 30 Nov
>N0XR-2 NS3T 14061.9 CQ 14 dB 26 wpm 1804z 30 Nov
>N0XR-2 NS3T 14017.4 CQ 7 dB 28 wpm 1759z 30 Nov
>N0XR-2 NS3T 14070.3 CQ 11 dB 28 wpm 1758z 30 Nov
>N0XR-2 NS3T 14008.7 CQ 18 dB 29 wpm 1724z 30 Nov
>N0XR-2 NS3T 14078.0 CQ 19 dB 29 wpm 1724z 30 Nov
>N0XR-2 NS3T 14008.7 CQ 23 dB 29 wpm 1724z 30 Nov
>N0XR-2 NS3T 14073.0 CQ 15 dB 31 wpm 1720z 30 Nov
>N0XR-2 NS3T 14040.1 CQ 14 dB 27 wpm 1639z 30 Nov
>DK5WL NS3T 14136.7 CQ 9 dB 27 wpm 1507z 30 Nov
>DK5WL NS3T 14119.3 CQ 9 dB 28 wpm 1504z 30 Nov
>N0XR-4 NS3T 7045.6 CQ 26 dB 25 wpm 1433z 30 Nov
>N0XR-4 NS3T 7048.5 CQ 23 dB 24 wpm 1432z 30 Nov
>W1UJ-3 NS3T 7000.2 CQ 20 dB 26 wpm 1427z 30 Nov
>N0XR-4 NS3T 7053.5 CQ 16 dB 26 wpm 1427z 30 Nov
>N0XR-4 NS3T 7037.5 CQ 27 dB 27 wpm 1424z 30 Nov
>W0QL NS3T 3537.9 CQ 11 dB 23 wpm 1056z 30 Nov
>N0XR-8 NS3T 3538.1 CQ 6 dB 23 wpm 1056z 30 Nov
>N0XR-6 NS3T 1805.2 CQ 2 dB 24 wpm 0336z 30 Nov
>N0XR-2 NS3T 14062.4 CQ 17 dB 29 wpm 1554z 29 Nov
>N0XR-2 NS3T 14059.9 CQ 13 dB 32 wpm 1551z 29 Nov
>N0XR-2 NS3T 14053.8 CQ 16 dB 28 wpm 1549z 29 Nov
>N0XR-2 NS3T 14066.7 CQ 14 dB 30 wpm 1426z 29 Nov
>N0XR-6 NS3T 1823.9 CQ 2 dB 25 wpm 1051z 29 Nov
>KC0YLK NS3T 7044.7 CQ 5 dB 23 wpm 1047z 29 Nov
>
>73 Jamie NS3T
>http://www.radio-sport.net
>Your home for ham radio contest news
>
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