Skimmer frequency accuracy
To be a good RBN citizen a skimmer should have a frequency accuracy of 2ppm or better.
To use the data below to improve the accuracy of your skimmer, multiply the current value of FreqCalibration in your skimmer software’s settings file with the suggested adjustment factor listed below.
The location of the settings files are:
CW Skimmer Server: %appdata%\Afreet\Products\SkimSrv\SkimSrv.ini
CW Skimmer: %appdata%\Afreet\Products\CwSkimmer\CwSkimmer.ini
The data listed below is based on yesterday’s RBN data, 00:00 to 23:59 UTC. This means that when making adjustments, changes in calibration will typically not have full impact on the listed data until the second day after the change.
The deviation estimates are based on spots on all active bands (40m and higher) from the respective skimmer. If different hardware is used for different bands, the deviation number may thus not represent the actual deviation for a particular band.
A link to the software used to produce the tables can be found at the bottom of this page. It runs as a cron job in an Ubuntu container on my Synology server and uploads to this WordPress website shortly after midnight UTC daily.
The deviation estimation is done in two steps. The first step uses a small number of highly accurate skimmers (called “anchors” in the code, typically GPSDO-controlled skimmers) as reference. The whole estimation process is then repeated one more time but using both the anchors as well as all skimmers determined to be the “good” as reference. The “good” skimmers are those with less than 0.15ppm average deviation from the anchors, producing more than 100 qualifying spots (the qualification criterion of spots are outlined below.)
Repeating the analysis with this this extended set of skimmers as frequency references drastically increases the geographical coverage of the analysis thereby increasing the number of qualifying spots which means a much more reliable deviation estimates for all skimmers. The skimmers used as reference skimmers in the second stage (i.e. both anchors and “good”) are marked with an asterisk in the table below.
When looking at the numbers, keep in mind that the deviations estimated by the algorithm are 100 to 1000 times smaller than the 100Hz resolution of RBN frequency data. The input data is thus extremely “noisy” which inevitably leads to statistical variations. This is also the reason for not including spots under a certain frequency. Doing so would skew the statistics and cause underestimation of the frequency error.
Due to propagation characteristics, operator behavior (e.g. small QSY), and just statistical variations due to the 100Hz rounding, some skimmers selected as reference skimmers in the first stage may have more than 0.2ppm deviation in the second stage. This is not an error.
If you do not see your skimmer in the list below in spite of it successfully feeding spots to RBN the most likely reason is that it is off in frequency. The analytics discards all spots from skimmers having more than 0.5kHz frequency error.
974158 RBN spots between 2023-12-10 00:00 and 23:59 UTC. 283567 spots (29.1%) were from reference skimmers (*). Average spot flow was 677 per minute from 199 active CW skimmers. 396526 spots from 198 skimmers qualified for analysis by meeting the following criteria: * Mode of spot is CW. * Also spotted by a reference skimmer within 1000 spots. * Also spotted by a reference skimmer within 10s. * SNR is 3dB or higher. * Frequency is 7000kHz or higher. * Frequency deviation from reference skimmer is 0.5kHz or less. * At least 5 spots from same skimmer in data set. Skimmer [ppm] Spots Adjustment ------------------------------------- 2E0EBM +0.2 60 1.000000238 3B8CW* +0.1 1691 1.000000143 3D2AG -0.3 844 0.999999750 5W1SA +2.1 95 1.000002064 7Q6M -3.3 204 0.999996746 9M2CNC +0.0 14 1.000000000 AA4VV -0.1 145 0.999999921 AC0C-1 +0.1 3255 1.000000121 BA6KC -0.1 211 0.999999915 BD7JNA -0.4 8 0.999999554 BG4GOV +0.0 55 1.000000000 BH4RRG +0.2 132 1.000000189 BH4RRG0 +0.3 175 1.000000306 BH4RRG00 +0.4 166 1.000000389 BH4RXP +0.1 492 1.000000126 BH4XDZ -0.0 160 1.000000000 CT1EYQ* +0.2 800 1.000000169 DC8YZ* +0.1 5260 1.000000080 DD5XX -1.3 3544 0.999998666 DE0QPG -1.3 1436 0.999998730 DE1LON +0.4 5847 1.000000369 DF2CK +1.0 7268 1.000001040 DF7GB* -0.0 3468 0.999999995 DJ1RK -2.5 3157 0.999997505 DJ2BC -0.3 3713 0.999999698 DJ9IE* +0.1 290 1.000000059 DK0TE -2.2 4615 0.999997756 DK3UA -1.0 455 0.999998979 DK9IP* -0.1 3034 0.999999905 DK9IP-1* +0.0 4180 1.000000001 DL0LA +0.2 3036 1.000000242 DL0PF -1.6 4320 0.999998434 DL1HWS* +0.0 4132 1.000000025 DL8LAS +0.9 4218 1.000000879 DL8TG* -0.1 4371 0.999999909 DL9GTB* -0.1 2608 0.999999939 DM5GG* +0.1 4052 1.000000059 DM6EE +0.0 161 1.000000044 DM7EE* +0.0 2455 1.000000048 DR4W -2.4 3600 0.999997630 E28AC +3.8 336 1.000003826 E77DX +2.4 750 1.000002436 EA1RX -2.2 157 0.999997773 EA1URA -0.5 1943 0.999999525 EA2CW -0.5 684 0.999999499 EA2RCF-4 -0.4 1444 0.999999600 ES2RR* +0.0 2327 1.000000007 EY8ZE -0.3 420 0.999999677 F1TRE -1.8 31 0.999998159 F4EGZ +0.7 2378 1.000000691 F4VVG -0.1 2056 0.999999856 F6IIT -0.5 312 0.999999494 F6KGL +0.2 952 1.000000206 G0KTN +0.3 3576 1.000000273 G3YPP* +0.1 427 1.000000067 G4IRN -0.2 741 0.999999756 G4ZFE* +0.1 4094 1.000000102 GI4DOH +0.2 911 1.000000151 HA1VHF -1.9 4025 0.999998114 HA8TKS +0.2 2854 1.000000208 HB9BXE* -0.0 2968 0.999999988 HB9DCO -0.4 2256 0.999999609 HG0Y +4.9 33 1.000004897 HG8A -1.7 4287 0.999998257 IK3STG +2.1 3325 1.000002083 IK4VET* +0.2 5279 1.000000173 IU0MVD +0.5 48 1.000000520 JH4UTP +0.5 369 1.000000470 JH7CSU1 +4.4 308 1.000004406 JI1HFJ +0.2 210 1.000000235 JJ2VLY -0.9 25 0.999999114 JN1ILK -1.4 731 0.999998567 K1RA -0.3 4898 0.999999696 K2PO/7 +0.6 2656 1.000000552 K3LR +0.0 888 1.000000019 K3PA-1* +0.4 3455 1.000000352 K4PP* -0.1 1947 0.999999898 K5EM* -0.1 1896 0.999999885 K5TR +0.6 1805 1.000000647 K6FOD* +0.0 2606 1.000000022 K7EK* +0.1 921 1.000000077 K7MJG +0.1 123 1.000000116 K9IMM* -0.1 2712 0.999999851 K9LC* -0.1 844 0.999999932 KA7OEI +0.1 160 1.000000109 KC4YVA +6.1 1427 1.000006054 KD2OGR* +0.2 616 1.000000169 KH6LC -0.2 1267 0.999999772 KL7RA -2.1 1622 0.999997922 KM3T* -0.0 4008 0.999999968 KM3T-2 -0.4 4794 0.999999599 KM3T-3 +0.4 4481 1.000000377 KO7SS -1.1 3112 0.999998862 KP3CW +0.5 4923 1.000000524 KV4TT +0.2 623 1.000000177 LA6TPA -3.5 1123 0.999996494 LZ3CB* -0.0 1822 0.999999999 LZ4AE +2.5 2320 1.000002537 LZ4UX* -0.1 1539 0.999999931 LZ5DI +0.2 1017 1.000000245 LZ7AA +0.6 1610 1.000000624 MM0ZBH -1.4 6100 0.999998638 MM3NDH* +0.0 4150 1.000000033 MW0MUT* -0.1 3759 0.999999895 N2QT -0.5 568 0.999999461 N4ZR +0.4 3236 1.000000442 N6TV +0.2 209 1.000000153 N7TUG +12.8 1270 1.000012812 N8DXE +0.5 1128 1.000000517 N9CO* -0.2 3481 0.999999784 N9MKC +0.2 1257 1.000000175 ND7K -2.7 3641 0.999997270 NG7M -0.8 1841 0.999999231 NH6HI +4.7 6 1.000004738 NJ4P +2.4 1875 1.000002368 NN3RP* +0.0 880 1.000000049 NU6XB +0.2 359 1.000000198 OE6TZE* +0.0 4080 1.000000023 OE9GHV* -0.0 4846 0.999999995 OG66X -0.9 231 0.999999135 OG73X -1.1 105 0.999998915 OH0K/6 -1.7 3312 0.999998281 OH2J -1.9 3313 0.999998118 OH4KA -1.8 603 0.999998153 OH6BG +4.0 2278 1.000004033 OK1FCJ* -0.0 4855 0.999999955 OK1HRA -3.0 3659 0.999996976 OK4QRO +1.5 3043 1.000001453 ON4EM +0.0 8 1.000000000 ON6ZQ -0.4 3257 0.999999620 OZ1AAB* +0.1 839 1.000000096 OZ1BZS* -0.0 519 0.999999960 OZ1HDF +0.2 152 1.000000164 OZ4ADX* +0.1 1870 1.000000076 P40L* -0.1 2486 0.999999923 PA0MBO* +0.1 1108 1.000000108 PA5KT -1.9 1274 0.999998090 PA8MM -1.2 106 0.999998754 PE5TT -0.7 3423 0.999999287 PJ2A +0.3 1921 1.000000299 R6YY +0.1 523 1.000000072 R9IR -0.1 715 0.999999898 RN4WA +0.5 1873 1.000000477 RU9CZD -2.0 1970 0.999997999 RW9AV -0.3 37 0.999999658 S50U +1.4 1749 1.000001414 S53A -0.2 5895 0.999999848 SE5E -0.5 3618 0.999999530 SM0TCZ -1.5 502 0.999998500 SM7IUN* -0.1 3919 0.999999920 SQ5J +1.2 3007 1.000001243 SV1CDN -1.0 51 0.999998975 SZ1A +0.0 216 1.000000000 TF3Y +1.9 2718 1.000001872 TF4M -0.9 2165 0.999999083 TI7W -0.2 5819 0.999999832 UA0S -3.1 700 0.999996923 UY2RA +0.8 2631 1.000000789 V51YJ +2.1 1098 1.000002104 VE6AO -2.0 2559 0.999997961 VE6JY +0.8 954 1.000000840 VE6WZ +2.7 3541 1.000002655 VE7CC +0.6 2420 1.000000555 VK2RH -0.3 28 0.999999745 VK3RASA +1.1 133 1.000001127 VK6ANC -1.1 1182 0.999998870 VR2FUN-77 -1.0 1098 0.999999048 VY0ERC +0.9 30 1.000000949 W1NT-2 +0.5 4584 1.000000486 W1NT-6 +0.3 6899 1.000000279 W2AXR +2.9 195 1.000002862 W2LB +0.0 20 1.000000000 W2MV +0.3 510 1.000000279 W2NAF +1.8 4376 1.000001779 W3DAN +0.5 1072 1.000000464 W3LPL -2.5 2114 0.999997509 W3OA* -0.1 4108 0.999999912 W3RGA +0.1 2796 1.000000132 W3UA* -0.0 6564 0.999999968 W4AX +3.3 625 1.000003280 W4KAZ -1.4 621 0.999998604 W6BB +0.3 550 1.000000274 W6YX* -0.0 2203 0.999999972 W8WTS -1.6 1627 0.999998408 W8WWV -2.1 3451 0.999997917 WA7AI +15.5 1871 1.000015477 WA7LNW -2.0 3391 0.999997992 WB6BEE* +0.0 2935 1.000000009 WC2L +0.5 2062 1.000000510 WE9V +2.4 2801 1.000002359 WF7U -0.4 1541 0.999999561 WS3W +0.2 361 1.000000190 WZ7I* -0.0 5772 0.999999967 XV9Q -0.1 64 0.999999944 YO4RDW +0.5 479 1.000000521 ZF9CW* +0.2 842 1.000000155 ZL2KS -1.8 154 0.999998227 ZL3X -2.6 539 0.999997433 Last updated 2023-12-11 00:16:23 UTC
Historical skimmer frequency accuracy
Below you will find historical accuracy data for the past ten days. Do not be concerned over minor daily variations. Since RBN spots only have 100Hz frequency accuracy, the input data is very noisy. Even for a perfectly accurate skimmer, the typical RMS rounding error across all shortwave bands is around 3ppm. This means that for a skimmer with 1000 spots per day the statistical variation is up to 0.2ppm. For skimmers with less than 100 spots per day the statistical variation can be above 2ppm. The content of the table below is based on the historical content of the above table.
Skimmer 1210 1209 1208 1207 1206 1205 1204 1203 1202 1201 --------------------------------------------------------------------- 2E0EBM +0.2 +0.3 +0.2 +0.2 +0.2 +0.1 +0.5 -20.8 3B8CW +0.1 +0.2 +0.1 -0.0 -0.4 -0.0 -0.2 -0.0 -0.5 -0.2 3D2AG -0.3 -0.0 -0.0 +0.0 +0.6 +0.0 +0.3 -0.1 +0.0 -0.2 3V8SS -1.9 -1.7 4X6FB +0.5 +0.0 5W1SA +2.1 +1.9 +3.6 +0.0 +1.5 +1.4 7N4XCV +0.5 +0.0 -0.2 +0.5 +0.3 +0.0 7Q6M -3.3 -3.1 -2.4 9M2CNC +0.0 +0.0 +0.0 +0.3 +0.6 +0.5 +0.0 +0.3 +0.2 -0.3 AA4VV -0.1 -0.0 +0.0 +0.0 -0.0 -0.0 -0.1 -0.0 +0.1 AC0C-1 +0.1 +0.2 +0.1 +0.0 +0.2 +0.2 +0.2 +0.2 +0.2 +0.1 BA6KC -0.1 -0.0 -0.2 +0.0 -0.4 +0.0 +0.0 -0.3 -0.2 +0.0 BD7JNA -0.4 -0.4 -2.7 BD8CS +0.0 -0.1 +0.1 BG2TFW +10.7 +7.1 +1.8 +6.1 +3.2 +6.4 BG2UKX0 +6.4 BG2UKX +5.7 BG4GOV +0.0 +0.0 +0.0 +0.2 BH4RRG00 +0.4 +0.4 +0.0 +0.9 +0.1 +0.0 +0.0 -0.2 +2.0 BH4RRG0 +0.3 +0.2 +0.0 +0.0 +0.0 +0.0 +0.0 +0.1 +0.2 BH4RRG +0.2 -0.0 +0.0 +0.0 +0.1 +0.0 +0.5 +0.0 +0.2 +0.1 BH4RXP +0.1 +0.1 -0.1 -0.2 -0.0 -0.2 -0.5 -0.7 -0.6 -0.5 BH4XDZ -0.0 +0.1 -1.1 -0.1 +0.0 +0.0 +0.0 -0.1 -0.2 +0.0 BI4RFP +0.0 +0.0 +1.3 +0.0 CT1EYQ +0.2 +0.0 +0.1 -0.1 +0.0 +0.2 +0.1 +0.1 +0.2 +0.1 CT7ANO -2.9 CX6VM +1.3 -3.7 -3.5 -3.8 -3.7 -3.8 -3.4 -2.9 -0.7 DC8YZ +0.1 +0.2 +0.2 +0.2 +0.1 +0.2 +0.1 +0.3 DD5XX -1.3 -1.8 -1.7 -1.6 -1.9 -1.6 -2.8 -2.5 -2.6 -1.8 DE0QPG -1.3 -1.6 -1.4 -1.3 DE1LON +0.4 -0.6 -0.2 -0.4 -0.4 +0.3 -0.2 -0.3 -0.3 +0.0 DF2CK +1.0 +1.2 +0.8 +0.8 +0.6 +0.7 +0.3 +0.3 +0.4 +0.5 DF2CK-1 +0.4 +0.1 +0.0 DF7GB -0.0 +0.1 -0.0 +0.0 +0.0 -0.0 +0.0 -0.1 +0.1 -0.0 DJ1RK -2.5 -3.0 -3.3 -3.4 -2.8 -3.0 -3.3 -4.0 -4.1 -3.6 DJ2BC -0.3 -1.2 -0.4 -0.6 -0.8 -0.6 -0.4 DJ9IE +0.1 DK0TE -2.2 -2.2 -1.8 -2.0 -2.4 -2.3 -2.7 -2.9 -2.9 -2.4 DK3UA -1.0 -3.1 -3.1 -5.3 DK8NE -1.0 DK9IP -0.1 -0.1 -0.1 -0.2 -0.0 -0.1 -0.1 -0.1 -0.2 -0.1 DK9IP-1 +0.0 +0.0 +0.1 +0.1 +0.1 -0.1 +0.1 +0.0 +0.1 +0.1 DL0LA +0.2 +0.3 +0.1 +0.1 +0.1 +0.3 +0.2 +0.3 +0.4 +0.2 DL0PF -1.6 -1.9 -1.9 -2.0 -2.1 -2.1 -1.9 -2.0 -1.7 -1.5 DL1HWS +0.0 +0.1 +0.0 -0.1 +0.0 +0.2 +0.1 +0.2 +0.3 +0.0 DL8LAS +0.9 +1.2 +0.7 +1.0 +1.0 +1.0 +0.9 +1.1 +1.1 +0.8 DL8TG -0.1 -0.0 -0.1 +0.1 -0.0 -0.1 -0.2 -0.1 -0.0 +0.0 DL9GTB -0.1 -0.0 -0.3 +0.2 +0.1 -0.5 -0.7 -0.6 +0.0 -0.3 DM5GG +0.1 +0.0 +0.0 -0.0 +0.1 -0.0 +0.0 +0.0 +0.0 -0.1 DM6EE +0.0 +0.1 +0.1 +0.1 -0.1 +0.2 +0.1 +0.1 +0.1 +0.1 DM7EE +0.0 +0.3 +0.0 +0.1 +0.2 +0.2 +0.1 +0.1 +0.1 +0.1 DR4W -2.4 -3.0 -3.9 -2.9 -3.6 -2.5 -3.8 -4.5 -4.5 -4.0 DV3A +1.9 -8.0 -6.0 -10.4 -6.6 -6.6 -6.1 E28AC +3.8 +4.0 +3.7 +2.4 +3.6 +4.4 +3.9 +4.7 +4.6 E77DX +2.4 EA1RX -2.2 -1.8 -6.7 -6.6 -2.5 -3.8 -6.1 -2.3 -3.8 -2.8 EA1URA -0.5 -0.2 +0.1 +0.5 +0.8 +0.9 +0.5 +0.7 +0.6 +0.3 EA2CW -0.5 +0.4 -0.4 -0.5 -0.4 -0.4 -0.4 -0.7 -0.5 EA2RCF-4 -0.4 -0.3 -0.4 -0.5 -0.4 -0.5 -0.3 -0.4 -0.3 -0.2 EA5WU -0.4 ES2RR +0.0 +0.0 +0.1 -0.1 +0.0 -0.1 -0.0 -0.0 -0.0 ET3AA -0.3 -0.5 -1.0 -1.2 -1.3 EU1ST +5.7 EY8ZE -0.3 -0.1 -0.2 -0.2 -0.4 -0.0 -0.2 -0.2 -0.1 -0.1 F1TRE -1.8 -2.7 F4EGZ +0.7 +0.9 +0.6 +0.7 +0.9 +0.9 +0.7 +0.7 +0.9 +0.9 F4VVG -0.1 -0.2 -0.2 -0.2 -0.1 +0.0 -0.0 -0.2 -0.0 -0.3 F6IIT -0.5 -1.4 -1.0 -2.3 -1.2 -1.4 -0.7 -1.5 -1.4 -1.1 F6KGL +0.2 -6.2 -8.6 -3.9 +0.0 +0.5 -0.0 +0.3 F8DGY +0.0 -0.1 -0.2 -0.3 -3.7 -2.0 -0.4 -1.2 -5.6 G0KTN +0.3 +0.5 +0.3 +0.4 +0.4 +0.4 +0.3 +0.4 +0.5 +0.4 G3XBI +0.3 +0.3 +0.4 G3YPP +0.1 +0.0 -0.2 +0.0 -0.3 -0.6 -0.1 +0.0 +0.0 +0.0 G4AON +0.6 +0.9 +0.9 +1.0 +0.8 +1.0 G4HSO +9.0 G4IRN -0.2 -0.3 -0.2 -0.4 -0.6 -0.4 -0.6 -1.0 -1.1 -0.9 G4ZFE +0.1 +0.2 +0.0 -0.2 -0.0 -0.0 +0.0 +0.0 +0.2 +0.2 GI4DOH +0.2 +0.3 +0.2 +0.1 +0.1 +0.2 +0.4 +0.3 +0.3 +0.3 HA1VHF -1.9 -2.2 -1.8 -1.7 -1.8 -1.8 -1.7 -1.9 -1.7 -1.3 HA5PP +1.4 HA8TKS +0.2 +0.3 +0.2 +0.3 +0.0 +0.5 +0.0 +0.3 +0.2 +0.2 HB9BXE -0.0 +0.1 +0.0 +0.0 +0.2 +0.2 +0.1 +0.1 +0.2 +0.1 HB9DCO -0.4 -0.3 -0.5 -0.5 -0.3 -0.4 -0.4 -0.4 -0.3 -0.4 HG0Y +4.9 +5.7 +6.4 +6.2 +5.6 +6.2 HG5FMV -0.1 +0.0 +0.2 +0.3 HG8A -1.7 -2.0 -1.2 -1.2 -0.8 -0.9 -0.8 -2.2 -2.0 -0.7 IK3STG +2.1 +2.5 +1.9 +1.8 +1.9 +1.8 +1.6 +1.9 +1.8 +1.6 IK4VET +0.2 +0.0 -0.0 +0.1 +0.0 -0.2 -0.0 +0.5 +0.8 IU0MVD +0.5 JH4UTP +0.5 +0.6 -0.1 -0.8 +0.0 JH7CSU1 +4.4 +5.1 +3.4 +3.7 +3.9 +3.0 +4.3 +3.9 +4.3 +3.3 JI1HFJ +0.2 +0.4 -1.0 -1.7 -1.5 -3.2 -3.3 +1.7 -7.0 -2.5 JJ2VLY -0.9 -1.7 -0.4 -0.7 -4.2 -2.9 -2.6 -0.8 -0.1 +0.6 JN1ILK -1.4 -1.7 -1.5 -1.2 +0.6 -1.6 -2.1 -3.6 -4.2 -3.8 K1RA -0.3 -0.3 -0.3 -0.6 -0.4 -0.2 +0.1 +0.2 -0.3 -0.3 K2PO/7 +0.6 +0.6 +0.3 +0.4 +0.5 +0.4 +0.7 +0.2 +0.6 +0.3 K3LR +0.0 +0.4 +0.4 -0.1 -0.2 -0.1 -0.1 +0.5 +0.2 -0.2 K3PA +0.0 K3PA-1 +0.4 -0.0 -0.0 +0.0 +0.0 +0.8 +0.5 +1.0 +1.0 +0.5 K4PP -0.1 +0.0 -0.2 -0.3 -0.2 -0.2 -0.2 +0.1 +0.1 -0.1 K5EM -0.1 +0.0 -0.0 -0.2 +0.0 -0.2 -0.1 -0.1 +0.0 +0.0 K5TR +0.6 +0.5 +0.7 +1.0 +1.1 +1.0 +0.9 +1.1 +0.5 +0.4 K6FOD +0.0 +0.2 +0.1 +0.2 +0.1 +0.2 +0.1 -0.2 +0.0 +0.1 K7EK +0.1 +0.3 -0.0 -0.1 -0.0 +0.2 +0.3 +0.2 +0.2 +0.2 K7MJG +0.1 +0.0 +0.1 +0.0 +0.4 +0.1 +0.3 +0.0 +0.4 +0.2 K9IMM -0.1 -0.0 +0.0 -0.1 +0.0 -0.1 -0.0 -0.2 -0.1 +0.0 K9LC -0.1 +0.1 +0.0 -0.1 -0.0 -0.0 -0.2 -0.1 +0.3 +0.4 KA7OEI +0.1 +0.2 +0.2 +0.2 +0.2 +0.2 +0.1 +0.0 +0.0 +0.1 KC4YVA +6.1 +6.1 +5.6 +5.2 +6.2 +5.1 +5.6 +4.9 +5.7 +5.3 KD2OGR +0.2 +0.1 +0.2 +0.1 +0.2 +0.2 +0.3 +0.1 +0.1 +0.1 KH6LC -0.2 -0.2 -0.1 +0.1 +0.0 -0.1 -0.1 -0.2 -0.0 -0.1 KL7RA -2.1 -2.2 -2.3 -1.7 -0.8 -0.4 -0.7 -0.4 -0.8 +0.0 KM3T -0.0 -0.0 -0.0 -0.2 +0.0 +0.1 -0.0 -0.0 -0.0 +0.0 KM3T-2 -0.4 -0.4 -0.3 -0.3 -0.2 -0.1 -0.2 -0.0 -0.1 -0.0 KM3T-3 +0.4 +0.1 -0.1 -0.2 -0.1 +0.0 -0.1 -0.1 -0.0 -0.1 KO7SS -1.1 -1.0 -0.7 -0.8 -0.9 -0.9 -0.9 -1.2 -1.7 -1.1 KP3CW +0.5 +0.8 +16.4 +16.5 +16.5 +16.4 +16.4 +16.5 +16.6 +15.7 KV4TT +0.2 +0.1 -0.1 -0.0 -0.0 +0.0 +0.1 +0.1 +0.1 +0.0 LA6TPA -3.5 -4.8 -6.6 -6.5 -6.1 -7.0 -8.2 -7.4 -7.4 -5.6 LZ3CB -0.0 -0.1 -0.0 +0.0 +0.2 -0.0 -0.1 -0.1 +0.0 +0.0 LZ4AE +2.5 +2.9 +1.0 +1.4 +1.5 +1.8 +2.0 +3.1 +3.0 +2.1 LZ4UX -0.1 -0.1 -0.0 -0.1 -0.1 +0.0 +0.0 -0.0 -0.1 -0.0 LZ5DB +0.1 +0.0 -0.2 +0.3 LZ5DB-2 +3.9 LZ5DI +0.2 +0.2 +0.1 -0.0 +0.2 +0.2 +0.1 +0.2 +0.4 +0.2 LZ7AA +0.6 +0.7 +0.4 +0.7 +0.8 +0.5 +0.5 +0.7 +0.8 +0.6 M0JYE -13.7 -11.0 -14.2 -9.3 -9.6 -12.6 MM0ZBH -1.4 +3.6 +1.5 -1.2 +0.1 -0.4 -1.4 -0.4 -0.8 +1.3 MM3NDH +0.0 +0.0 -0.0 +0.0 -0.1 +0.0 +0.0 +0.0 +0.0 +0.0 MW0MUT -0.1 -0.1 -0.1 -0.0 -0.3 +0.0 -0.1 -0.2 -0.4 +0.0 N2QT -0.5 -2.1 -2.0 +1.0 +1.6 +1.1 +1.5 +1.6 +0.9 N4ZR +0.4 +0.2 +0.0 -0.0 +0.1 +0.0 +0.1 -0.1 +0.1 +0.1 N6TV +0.2 +0.0 +0.2 +0.5 +0.2 +0.3 +0.3 +0.2 +0.2 +0.2 N7TUG +12.8 +12.0 +13.0 +13.5 +13.4 +14.0 +13.2 +13.4 +13.3 +13.8 N8DXE +0.5 +0.8 +0.6 +0.6 +0.5 +0.3 +0.5 +0.9 +0.5 +0.3 N9CO -0.2 +0.2 +0.0 -0.1 -0.0 -0.0 +0.0 +0.1 +0.0 +0.0 N9MKC +0.2 +0.2 +0.0 ND7K -2.7 -2.5 -1.5 -1.1 -1.4 -1.4 -1.7 -2.2 -2.6 -1.8 NG7M -0.8 -0.5 -0.3 -0.3 -0.3 -0.2 -0.3 -0.1 -0.2 -0.2 NH6HI +4.7 NJ4P +2.4 +3.2 +1.6 +2.4 +4.8 +4.1 +4.5 +2.3 NN3RP +0.0 +0.0 -0.2 -0.1 -0.4 +0.0 -0.1 -0.1 +0.3 +0.0 NU6XB +0.2 +0.0 +0.4 +0.2 +0.6 +0.5 +0.4 +0.2 +0.3 +0.2 NX5M +5.8 +5.6 +5.7 +5.5 +5.7 +6.0 OE6ADD +0.9 OE6TZE +0.0 +0.1 -0.0 +0.0 -0.0 +0.2 +0.0 +0.1 +0.2 +0.2 OE9GHV -0.0 -0.1 -0.0 +0.1 -0.0 +0.0 -0.1 -0.1 +0.0 -0.0 OG66X -0.9 -0.9 -0.5 -0.4 -0.0 -0.4 -1.3 -1.0 -1.2 +0.0 OG73X -1.1 +0.5 OH0K/6 -1.7 -1.8 -1.5 -0.6 -2.9 -1.4 -1.8 -1.7 -2.5 -1.4 OH2BBT +1.9 OH2J -1.9 +3.8 +15.2 +14.0 +14.0 -15.3 -15.9 -13.7 -5.6 -7.0 OH4KA -1.8 -2.3 -2.1 -2.5 -2.6 -3.2 -2.5 -2.3 -2.2 -1.6 OH6BG +4.0 +3.1 +4.7 +2.8 +3.6 +3.4 +4.1 +5.2 +4.8 +4.9 OH8KA +1.2 +1.2 +1.6 +1.4 +1.3 +1.5 +1.4 +1.6 OK1FCJ -0.0 +0.2 +0.1 +0.1 +0.2 +0.2 -0.1 -0.1 -0.0 -0.0 OK1HRA -3.0 -3.5 -3.7 -3.6 -3.6 -3.3 -3.3 -3.8 -4.0 -3.8 OK4QRO +1.5 +1.7 +0.0 +0.3 +0.2 +0.1 +0.1 +0.2 ON4EM +0.0 +0.0 ON6ZQ -0.4 -0.8 -0.5 -0.6 -0.5 -0.5 -0.5 -0.9 -0.8 -0.5 ON7KEC +2.5 +0.5 +0.6 +0.6 OZ1AAB +0.1 +0.2 +0.1 +0.2 -0.2 +0.3 +0.1 +0.1 -0.7 -3.0 OZ1BZS -0.0 -0.0 +0.1 +0.0 +0.0 +0.1 +0.2 +0.0 +0.0 -0.1 OZ1HDF +0.2 +0.3 -2.0 +1.0 OZ4ADX +0.1 +0.1 +0.0 -0.0 -0.2 +0.0 -0.0 -0.0 +0.1 -0.1 P40L -0.1 -0.1 +0.1 -0.3 -0.1 +0.0 -0.0 -0.1 -0.2 -0.1 PA0MBO +0.1 +0.3 +0.0 +0.1 +0.0 +0.5 -0.0 +0.1 +0.2 +0.2 PA2SQ +0.3 +0.7 PA5KT -1.9 -2.0 PA5WT -0.5 -0.6 -0.5 PA8MM -1.2 -0.6 -0.2 -0.4 -0.4 -0.4 -0.5 -3.1 -4.8 -2.4 PE5TT -0.7 +0.0 -0.2 -1.0 -0.2 -0.2 -0.9 -0.7 -0.0 -0.7 PJ2A +0.3 +0.4 +0.1 -0.4 -0.2 +0.2 -0.1 -0.0 -0.1 -0.0 R6YY +0.1 +0.0 -0.0 +0.1 +0.2 +0.1 +0.2 +0.1 +0.3 +0.0 R9IR -0.1 +0.0 +0.1 +0.0 -0.2 -0.1 -0.0 +0.6 +0.4 +0.3 RN4WA +0.5 +0.4 +0.4 +0.4 -0.2 +0.3 +0.4 +0.6 +0.7 +0.6 RU9CZD -2.0 -7.0 -13.6 -12.5 -9.8 -6.6 -4.8 -4.6 -1.5 -2.4 RW9AV -0.3 -4.8 -1.1 -1.1 -0.9 -0.7 -1.1 -0.9 -1.0 -1.0 S50ARX +2.4 +2.9 +3.1 +2.9 +2.8 +3.1 +3.5 +3.2 S50U +1.4 +1.9 +1.7 +1.8 +1.7 +1.8 +1.8 +1.8 +2.1 +1.4 S53A -0.2 -0.1 -0.1 -0.3 -0.2 -0.1 +0.0 +0.2 +0.3 +0.5 SE5E -0.5 -1.3 -1.6 -2.5 -2.6 -2.2 -1.4 -1.4 -1.2 -0.8 SM0TCZ -1.5 -1.3 -2.5 -1.6 -1.2 -3.6 -0.5 -4.0 -4.9 -5.0 SM7IUN -0.1 -0.2 -0.0 -0.1 +0.0 -0.0 -0.3 -0.0 +0.1 -0.1 SQ5J +1.2 +1.5 +1.2 +1.5 +1.4 +1.5 +1.4 +1.5 +1.5 +1.3 SV1CDN -1.0 -1.3 -0.4 -1.3 -1.3 -1.3 -0.8 -0.9 -0.6 -0.6 SV1DPJ +0.8 +0.3 +0.1 SZ1A +0.0 +0.5 -0.3 -0.7 -0.2 -0.2 -0.1 +0.6 +0.6 +0.4 TF3Y +1.9 +2.0 +1.4 +1.7 +1.4 +2.0 +1.5 +1.5 +1.2 +1.5 TF4M -0.9 -1.0 -1.2 -1.2 -0.9 -1.1 -1.0 -1.1 -1.5 -1.1 TI7W -0.2 -0.2 -0.2 -0.2 -0.1 -0.1 -0.2 -0.1 -0.0 -0.0 TZ4AM -3.0 -2.2 UA0S -3.1 -4.2 -5.4 -4.0 -2.9 -2.8 -2.8 -3.6 -3.6 -3.1 UY2RA +0.8 +1.1 +0.8 +1.1 +1.1 +1.3 +1.1 +1.3 +0.9 +0.9 V51YJ +2.1 +2.2 +1.6 +1.7 +1.9 +2.0 +2.2 +1.6 +1.4 +1.5 VE6AO -2.0 -2.5 -1.5 -1.4 -1.1 -0.6 -1.3 -1.9 -1.8 -0.9 VE6JY +0.8 +0.7 +1.0 +1.1 +1.4 +1.2 +0.9 +0.5 +1.4 +0.6 VE6WZ +2.7 +3.3 +2.8 +2.3 +2.6 +1.8 +2.6 +2.4 +2.5 +2.5 VE7CC +0.6 +0.6 +0.4 +0.7 +0.5 +0.4 +0.4 +0.3 +0.2 +0.3 VK2EBN +0.0 +0.0 +0.2 VK2GEL +0.4 -0.9 +2.9 VK2RH -0.3 +0.1 +0.0 +0.0 +0.3 +0.0 +0.0 +0.0 +0.1 +0.0 VK3RASA +1.1 +0.2 +1.0 +0.8 -0.4 +0.3 +1.3 +1.4 +0.1 +0.2 VK6ANC -1.1 -1.0 -0.9 -0.9 -0.9 -1.2 -0.8 -0.8 -0.6 -0.6 VP2VMM +4.2 +4.7 +5.5 VR2FUN-77 -1.0 -0.9 -0.9 -0.6 -0.8 -0.7 -0.7 -0.8 -0.6 -0.3 VY0ERC +0.9 +0.6 +0.2 +1.2 +0.8 +0.5 +1.0 W1NT-2 +0.5 +0.4 +0.3 +0.2 +0.4 +0.3 +0.3 +0.3 +0.3 +0.4 W1NT-6 +0.3 +0.2 +0.1 +0.1 +0.2 +0.2 +0.2 +0.2 +0.3 +0.2 W2AXR +2.9 W2LB +0.0 +0.6 +1.6 +1.5 +1.5 +0.8 W2MV +0.3 +0.1 +0.3 +0.1 +1.0 +0.3 +0.1 +0.3 +0.0 +0.3 W2NAF +1.8 +1.6 +0.7 +0.9 +1.3 +1.0 +1.1 +1.1 +1.2 +1.1 W3DAN +0.5 +0.7 +0.4 +0.5 +0.6 +0.3 +0.3 +0.8 +0.6 +0.2 W3LPL -2.5 -2.6 -2.4 -2.6 -2.7 -2.5 -2.4 -2.5 -2.9 -2.3 W3OA -0.1 -0.0 -0.1 -0.1 -0.0 -0.0 -0.0 -0.0 -0.2 -0.0 W3RGA +0.1 +0.2 +0.0 -0.2 -0.1 -0.2 -0.1 +0.0 +0.0 -0.1 W3UA -0.0 -0.0 -0.0 -0.0 -0.1 -0.0 -0.0 -0.0 -0.2 -0.0 W4AX +3.3 +2.9 +3.1 +2.6 +4.5 +3.4 +3.0 +2.8 +3.0 +3.6 W4KAZ -1.4 -2.6 -2.0 +0.0 -0.0 -1.0 -2.8 W6BB +0.3 +0.3 +0.2 +0.4 +0.5 +0.4 +0.7 +0.1 +0.3 +0.1 W6YX -0.0 +0.1 -0.1 +0.1 +0.0 +0.1 +0.2 +0.1 +0.0 +0.0 W8WTS -1.6 -1.7 -0.5 -1.0 -1.2 -0.8 -1.0 -0.7 -0.9 -0.6 W8WWV -2.1 -2.0 -1.5 -1.6 -1.6 -1.5 -1.5 -1.7 -1.7 -1.3 WA7AI +15.5 +14.9 +14.7 +15.3 +15.1 +15.3 +15.3 +16.7 +16.0 +14.1 WA7LNW -2.0 -2.0 -0.8 -0.4 -0.6 -0.7 -1.0 -1.4 -2.2 -1.1 WB6BEE +0.0 -0.0 -0.1 -0.0 -0.0 +0.0 +0.0 -0.0 -0.1 +0.1 WC2L +0.5 +0.4 +0.2 +0.1 +0.5 +0.3 +0.6 +0.4 +0.5 WE7L +0.0 WE9V +2.4 +2.5 +6.6 +7.0 +6.5 +7.3 +6.7 +6.6 +5.5 +0.4 WF7U -0.4 -0.5 -0.2 -0.3 -0.1 -0.4 -0.4 -0.3 -0.4 -0.1 WS3W +0.2 +0.2 -0.4 -2.3 +0.9 -1.3 +0.7 +0.3 +1.0 +0.3 WZ7I -0.0 -0.0 -0.0 -0.0 +0.0 +0.0 +0.0 -0.0 -0.0 +0.0 XV9Q -0.1 -0.1 +0.0 +0.0 +0.0 YO4RDW +0.5 +0.6 +0.5 +0.5 +0.5 +0.3 +0.2 +0.6 +0.6 +0.2 ZF1A +0.9 +0.6 +0.8 +1.0 +0.9 +0.8 +0.9 +1.1 ZF9CW +0.2 -0.6 +0.1 +0.1 +0.1 -0.1 +0.2 +0.3 -0.1 -0.2 ZL2KS -1.8 -1.8 -1.1 -1.7 -2.0 -2.6 -1.8 -1.2 -1.7 -1.5 ZL3X -2.6 -2.2 -1.7 -1.7 -1.8 -2.5 -2.3 -1.3 ZL4YL +0.9 +1.0 +1.2 +1.6 +1.1 +1.1 Last updated 2023-12-11 00:16:42 UTC
Anchor skimmers
The below skimmers use external frequency references and are confirmed to have continuous, high accuracy. Their accuracy is also confirmed against each other on a daily basis.
DF7GB ES2RR KM3T LZ3CB LZ4UX MM3NDH OE9GHV WB6BEE Last updated 2023-12-11 00:16:42 UTC
It is the owners of these skimmers who make this web page possible. Thank you.
To get good geographic coverage and a good size dataset, a two-step method is used for the analysis shown above. Since the second step also relies on spots from skimmers with slightly lower accuracy the displayed error for the anchor skimmers may not always be 0.0, even though they are perfectly accurate.
Software
The software powering this page can be found on github.