Decided to do a little manual analysis of the spots generated by the WE9V
CW Skimmer, on this past CQWW CW weekend.
First, some background. The WE9V CW Skimmer is co-located with my contest
station. Because I'm only on 1.2 acres, I cannot get a lot of separation
between my TX antennas and the Skimmer antenna. When transmitting, the red
LED indicating excessive RF comes on, so I homebrewed a box that shorts out
the Skimmer RX antenna whenever either of my SO2R radios transmit, in order
to save the front-end from damage. Therefore, the Skimmer doesn't hear
very well whenever I'm transmitting. In years past, I've mostly S&P'd the
entire contest, so it wasn't a major issue. This year I CQ'd quite a bit
more, so the RX duty cycle was fairly low. I estimate around 35%. Due to
the high leakage of the relay, signals are attenuated enough to not have
the overload light come on, and yet still have the skimmer hear. What I'm
saying is that the skimmer isn't totally deaf/useless when transmitting,
and still makes plenty of spots, just not as many or as quick as it could
if it wasn't being switched.
The WE9V CW Skimmer is a QS1R skimming seven 192kHz segments at once during
the contest. Because of the 192kHz bandwidth, it can cover the entire CW
band segments, including above 14100, above 21100, and even all the way up
to 28300. Some CW Skimmers with only 96kHz bandwidth may not cover those
areas. It runs on my HTPC which is just an i3, but I never saw CPU usage
above 20%. Antenna is a 30M wire 1/4wl groundplane with 3 radials,
located about 150' away from the closest TX antenna. From 0030z to 1030z
it skims the low bands which is the entire 17M-160M bands. From 1030z to
0030z, it skims the high bands, from 10M-40M, excluding 30M. I currently
have S9+25dB noise on 160M, so the Skimmer has horrible performance there.
Any spots getting through that were VERY strong, even with low reported SNR.
Quick stats, includes spots of USA/VE:
89,259 total contest band spots
430 WARC band spots over the same period
4,703 unique calls
2,651 calls spotted >=2 times
9 spotted >500 times
51 spotted between 200 and 500 times
165 spotted between 100 and 200 times
2052 calls spotted only once...they could be busted calls, but in looking
them over, many of them are real calls. Either they didn't CQ much, ID
well enough for Skimmer to validate it, or I just didn't hear them
well/often. I did notice many skimmers (not just mine) would spot people
answering a CQ as a CQing station. Hard to weed those out, especially in a
single Skimmer's spot log.
Below is a list of the 30 most spotted stations, including their total
spots, spots on a band, and the average SNR of the spots on that band. I'm
not sure they will come across the reflector well, so if they don't, I
apologize in advance. Maybe I could post to a webpage or something, and
include more of the list if there's interest.
73,
Chad WE9V
Call Total 10M SNR 15M SNR 20M SNR 40 SNR 80 SNR 160 SNR HK1NA 749 78
17.2 86 27.4 254 21.9 153 26.5 87 20.6 91 8.6 K3LR 653 27 7.6 57 11.1 168
23.4 187 26.0 108 30.3 106 22.0 W3LPL 631 1 10.0 52 13.1 181 23.4 207 32.3
99 29.8 91 9.2 WE3C 584 5 3.8 61 13.6 169 28.6 179 34.2 87 25.2 82 9.8
W2FU 567 11 6.6 54 10.8 133 28.0 195 32.3 106 32.0 68 20.0 PJ2T 563 6 15.0
74 23.7 203 19.1 162 27.3 85 18.1 32 7.4 VC7M 561 65 21.9 88 27.8 131 25.0
128 24.6 84 20.5 65 4.5 DR1A 518 41 23.8 83 30.7 151 24.7 159 32.1 84 18.8
CN2AA 517 48 22.7 85 23.6 191 25.2 131 24.6 62 23.6 WK1Q 477 2 9.0 64 30.5
138 28.2 162 26.3 78 23.1 33 7.1 N6RO 475 80 21.8 86 26.8 95 25.1 169 23.1
32 15.7 13 3.5 NR4M 442 7 19.9 56 14.2 122 21.6 151 32.7 77 26.9 29 15.2
9A1A 435 39 22.9 53 30.8 146 21.1 135 26.6 62 19.6 EA5KA 433 47 19.9 77
24.8 121 22.4 137 27.6 51 15.8 DF0HQ 414 41 21.3 63 28.4 85 18.0 153 26.1
72 18.6 N4WW 407 20 19.5 109 33.3 125 30.8 127 35.4 22 30.8 4 8.0 KH7XX
391 69 17.8 84 21.6 72 21.7 116 26.4 50 19.3 NP4Z 388 51 17.1 90 23.4 91
25.8 116 28.1 40 18.4 ED1R 383 44 15.8 79 20.5 81 20.1 122 27.6 57 18.4
K0RF 383 2 5.5 91 36.5 97 37.6 163 34.5 29 27.9 1 15.0 LZ9W 363 24 24.1 49
27.4 114 20.5 128 28.0 48 21.2 TM6M 361 46 23.8 93 28.2 81 24.3 83 33.0 58
20.3 NP2X 348 42 15.9 91 24.4 72 23.5 104 24.4 39 19.5 TM1A 346 34 18.9
74 24.7 100 18.5 111 21.4 27 18.8 NQ4I 344 5 6.0 78 19.7 90 26.2 138 40.4
31 36.6 2 10.0 OL4A 343 40 24.4 58 29.2 75 24.2 111 31.9 59 19.4 G5W 310
18 12.3 50 22.1 75 21.0 115 23.8 51 18.0 CR3L 307 19 11.1 77 18.8 79 22.9
112 20.6 20 20.8 LX7I 305 13 19.9 65 28.0 88 23.8 88 27.7 51 21.1 KP2Q
289 18 10.6 85 18.1 82 21.9 89 28.5 15 18.3
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