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.
if you want to implement an automated calibration of your skimmer you can access the skew data in machine-readable CSV format here https://sm7iun.se/rbnskew.csv
450589 RBN spots between 2024-04-18 00:00 and 23:59 UTC. 135930 spots (30.2%) were from reference skimmers (*). Average spot flow was 313 per minute from 202 active CW skimmers. 243557 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 ------------------------------------- 2E0INH* -0.0 2993 0.999999989 3B8CW -2.2 305 0.999997782 3D2AG +0.5 14 1.000000510 3V8SS -1.6 1987 0.999998446 7N4XCV +0.6 67 1.000000639 9M2CNC +0.3 158 1.000000309 AA0O* +0.0 1057 1.000000034 AC0C-1* -0.0 1946 0.999999973 BA6KC -0.1 165 0.999999949 BA6KC1 +0.3 19 1.000000291 BD4QJP +2.8 52 1.000002759 BD7JNA -0.2 99 0.999999836 BD8CS* -0.0 511 0.999999956 BG0AJO +0.2 46 1.000000155 BG4GOV +0.1 57 1.000000125 BG4WOM -0.1 197 0.999999936 BH4RRG +0.0 134 1.000000000 BH4RXP -4.8 308 0.999995153 BH4XDZ +0.0 96 1.000000037 BI4MPH +0.3 124 1.000000288 BI4MPH-1 +0.1 53 1.000000135 BI4RFP +0.2 99 1.000000164 BI4RFP-YZ +0.4 120 1.000000383 BI4SSB +0.3 97 1.000000278 CR6K -5.3 2673 0.999994727 CX6VM -4.8 176 0.999995234 DC8YZ +0.1 3231 1.000000147 DD5XX -1.4 978 0.999998636 DE1LON* -0.1 2455 0.999999932 DF2CK* -0.1 4990 0.999999906 DF7GB* -0.0 2629 0.999999985 DJ2BC -0.2 2220 0.999999755 DJ9IE +0.0 109 1.000000000 DK0TE +0.4 2458 1.000000380 DK3UA -8.6 1088 0.999991406 DK3WW +0.9 2127 1.000000907 DK9IP* -0.1 1866 0.999999928 DK9IP-1* +0.1 2445 1.000000087 DL0LA* +0.2 1017 1.000000175 DL0PF* -0.1 3343 0.999999915 DL1EFW +1.0 380 1.000000957 DL1HWS +0.3 2762 1.000000309 DL8LAS* -0.1 3278 0.999999898 DL8TG* +0.1 2845 1.000000082 DR4W -3.3 2624 0.999996663 DR5X +0.5 3079 1.000000489 E28AC +4.7 157 1.000004737 EA1RX -2.4 165 0.999997621 EA1URA +0.7 1919 1.000000731 EA2CW +0.5 1824 1.000000467 EA4FIT +0.0 5 1.000000000 EA5RQ/A +0.0 16 1.000000000 ES2RR* -0.1 3179 0.999999945 F6IIT -1.0 157 0.999998971 F8DGY +0.1 370 1.000000072 G0KTN +0.3 2342 1.000000285 G3XBI +0.3 553 1.000000253 G3YPP +0.2 95 1.000000225 G4AON +1.0 218 1.000001034 G4IRN +0.6 2318 1.000000597 G4ZFE +0.2 3041 1.000000229 GI4DOH +0.3 559 1.000000286 HA1VHF -1.1 2059 0.999998924 HA6PX* -0.1 2473 0.999999913 HA8TKS* +0.2 1371 1.000000236 HB9BXE +0.1 2166 1.000000110 HB9DCO -0.5 1805 0.999999515 HG0Y +5.7 199 1.000005712 HG8A* +0.0 2828 1.000000045 IK3STG +1.6 401 1.000001575 IK4VET +1.5 3173 1.000001545 IK7YTT -0.7 1408 0.999999292 IZ2CPS +1.0 718 1.000001012 J68HZ +11.5 809 1.000011546 JH7CSU1 +2.9 141 1.000002914 JI1HFJ -1.7 98 0.999998298 JJ2VLY +0.4 241 1.000000421 JN1ILK -0.1 283 0.999999913 K1RA +0.7 2048 1.000000691 K2PO/7 +0.7 708 1.000000666 K3PA-1* +0.0 1190 1.000000012 K3PA-2 -1.1 119 0.999998879 K4PP +0.9 1005 1.000000876 K5TR +0.9 733 1.000000902 K6FOD* +0.0 473 1.000000000 K7EK +0.9 415 1.000000884 K7MJG +0.7 272 1.000000717 K9IMM* -0.0 827 0.999999975 K9LC* +0.0 1816 1.000000008 KA7OEI +0.3 565 1.000000284 KC4YVA +5.4 681 1.000005393 KH6LC +0.6 250 1.000000612 KM3T* +0.0 1489 1.000000000 KM3T-2 +0.4 2308 1.000000394 KM3T-3 +0.3 2426 1.000000288 KO7SS -0.6 96 0.999999448 KP3CW +0.3 1588 1.000000336 KV4TT* -0.1 1867 0.999999919 LA6TPA -2.9 1001 0.999997072 LA7GIA -0.1 927 0.999999926 LB9KJ -1.3 554 0.999998702 LU8XW -1.9 18 0.999998107 LY3G +0.3 172 1.000000290 LZ3CB -0.1 1875 0.999999912 LZ4AE +3.5 2470 1.000003534 LZ4UX* +0.0 1663 1.000000041 LZ5DI +0.5 1313 1.000000534 LZ7AA +0.6 1908 1.000000602 MM0ZBH +0.2 3397 1.000000204 MM3NDH* +0.0 3499 1.000000009 MW0MUT +0.2 2327 1.000000161 N0OI +0.5 1050 1.000000476 N2QT +0.3 1414 1.000000339 N4ZR +0.1 476 1.000000142 N6TV +0.6 924 1.000000565 N7TUG +14.3 204 1.000014275 N9CO* +0.1 1180 1.000000058 ND7K -1.2 1300 0.999998836 NG7M -0.4 928 0.999999556 NN3RP +0.9 688 1.000000868 NT6Q +4.0 360 1.000004010 NU6XB +0.3 233 1.000000306 OE6ADD +0.2 3104 1.000000169 OE6TZE* +0.1 2200 1.000000080 OE9GHV* -0.1 3112 0.999999921 OG66X* +0.0 1296 1.000000032 OH6BG +4.5 2782 1.000004487 OK1HRA -4.3 3017 0.999995742 OK4QRO +1.4 2633 1.000001445 ON6ZQ -0.3 2100 0.999999674 OZ1AAB* +0.0 1020 1.000000048 OZ1BZS -0.0 166 0.999999957 OZ4ADX* +0.3 357 1.000000251 PA0MBO +0.3 929 1.000000348 PA8MM* -0.1 1743 0.999999862 PE5TT -0.3 1871 0.999999737 R1LB* +0.0 613 1.000000023 R6YY +0.4 508 1.000000372 RK3TD +0.8 1498 1.000000778 RK3TD-2 +0.4 1135 1.000000406 RN4WA +0.9 1802 1.000000919 RU9CZD -3.6 2067 0.999996362 S50U* +0.1 1277 1.000000100 S53A +1.4 3839 1.000001365 S53WW -0.6 2866 0.999999383 SE5E* +0.1 3347 1.000000077 SM0TCZ -3.6 157 0.999996424 SM7IUN* -0.0 2722 0.999999964 SQ5J +3.6 2407 1.000003556 SQ5OUO +5.9 2355 1.000005928 SV1CDN -0.4 12 0.999999604 SZ1A -0.4 1611 0.999999636 TF3Y +1.2 2247 1.000001235 TF4M -1.3 3428 0.999998670 TI7W -0.4 1605 0.999999624 TZ4AM +0.6 20 1.000000557 UA0S +1.1 911 1.000001087 UD4FD +0.8 318 1.000000753 UY2RA +1.8 1239 1.000001798 V51YJ +1.8 49 1.000001809 VE6AO -1.8 437 0.999998157 VE6JY +0.2 110 1.000000162 VE6WZ -1.2 778 0.999998838 VE7CC +0.6 285 1.000000594 VK2GEL +4.4 142 1.000004403 VK2RH -0.1 89 0.999999898 VK3RASA -0.8 134 0.999999249 VK6ANC -0.9 127 0.999999059 VR2FUN-74 +6.0 382 1.000006015 VR2FUN-77* +0.1 1138 1.000000051 VU2CPL +3.2 226 1.000003245 VY0ERC +0.0 5 1.000000000 W1NT-2 +0.4 519 1.000000384 W1NT-6 +0.3 2659 1.000000272 W1UE -5.3 557 0.999994706 W2MV +0.5 360 1.000000474 W2NAF +1.2 1384 1.000001188 W3LPL -4.0 1928 0.999995990 W3OA* -0.0 1792 0.999999959 W3UA* -0.1 2262 0.999999937 W4AX +4.6 112 1.000004570 W4KAZ -0.4 1145 0.999999581 W6BB +0.5 345 1.000000524 W6YX +0.3 1182 1.000000258 W8WTS +0.2 1138 1.000000208 W8WWV -1.4 1762 0.999998611 WA7LNW +0.1 108 1.000000113 WB6BEE* +0.1 833 1.000000077 WC2L +0.2 64 1.000000222 WC8GOP +3.5 142 1.000003453 WE9V -0.1 1693 0.999999905 WV4P +0.7 896 1.000000732 WZ7I* +0.1 2851 1.000000067 YO2MAX +6.0 2741 1.000005952 YO4RDW +0.5 260 1.000000466 ZF9CW -0.6 827 0.999999355 ZL3X -0.8 365 0.999999212 ZL4YL +1.3 82 1.000001255 Last updated 2024-04-19 00:15:42 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 0418 0417 0416 0415 0414 0413 0412 0411 0410 0409 --------------------------------------------------------------------- 2E0INH -0.0 -0.1 -0.0 -0.0 +0.0 +0.0 -0.0 +0.0 -0.1 -0.0 3B8CW -2.2 -2.0 -2.4 -1.9 -2.2 -2.0 -1.5 +2.2 +19.2 +19.2 3D2AG +0.5 +0.4 +0.1 +0.0 +0.2 +0.1 +0.2 -0.1 +0.5 +0.3 3V8SS -1.6 -1.8 -0.7 -6.1 -4.5 -4.5 -1.6 -1.6 -1.7 -1.7 5W1SA +1.0 +1.8 +1.2 7N4XCV +0.6 +0.7 +0.0 +0.8 +0.7 +0.1 +0.4 -0.1 9M2CNC +0.3 +0.7 +0.4 +0.6 +0.9 +0.8 +0.2 +0.3 +0.6 +0.2 AA0O +0.0 +0.1 +0.2 +0.1 +0.1 +0.1 +0.0 -0.0 AA4VV -0.1 -0.0 +0.0 -0.1 +0.0 +0.0 -0.1 AC0C-1 -0.0 -0.1 +0.1 +0.0 -0.0 -0.1 -0.1 -0.0 -0.1 -0.0 BA6KC -0.1 -0.1 +0.2 -0.0 -0.1 -0.2 -0.0 +0.0 +0.0 BA6KC1 +0.3 +0.0 BD4QJP +2.8 +1.7 +1.8 +3.1 +3.1 +2.9 +1.2 +1.4 BD7JNA -0.2 -0.2 +0.3 +0.1 -0.1 -0.1 -0.0 +0.1 -0.1 +0.0 BD8CS -0.0 +0.0 +0.1 -0.1 +0.0 -0.1 -0.1 -0.2 +0.0 -0.0 BG0AJO +0.2 +0.2 +1.7 +0.1 +0.5 +0.4 +0.4 +0.9 +0.5 +0.1 BG4GOV +0.1 +0.3 +0.0 +0.0 +0.2 +0.2 +0.3 +0.0 +0.6 +0.6 BG4WOM -0.1 +0.2 -0.1 +0.1 +0.0 +0.0 +0.1 -0.1 +0.1 +0.0 BH4RRG +0.0 -0.0 -0.1 +0.0 -0.0 -0.1 -0.1 +0.1 +0.0 -0.1 BH4RXP -4.8 -4.8 -5.1 +0.6 +0.7 +0.7 +0.3 +0.4 +0.3 +0.4 BH4XDZ +0.0 +0.1 -0.3 +0.1 +0.1 +0.0 +0.0 +0.2 +0.0 +0.1 BI4MPH +0.3 +0.1 +0.0 +0.1 +0.1 +0.1 +0.0 -0.1 +0.1 +0.2 BI4MPH-1 +0.1 -0.1 +0.2 +0.0 +0.0 +0.3 +0.2 +0.1 +0.2 BI4RFP +0.2 +0.3 +0.0 +0.1 +0.3 +0.2 +0.5 +0.4 +0.7 +0.3 BI4RFP/4 +0.2 +0.2 BI4RFP-YZ +0.4 +0.1 +0.4 +0.2 +0.2 +0.1 +0.5 +0.2 +0.4 +0.7 BI4SSB +0.3 +0.1 +0.0 +0.1 +0.1 +0.2 +0.0 +0.0 +0.0 CR6K -5.3 -5.3 -5.1 -5.2 -5.4 -5.7 -5.9 -5.8 CX6VM -4.8 -4.3 -2.8 -3.3 -3.8 -4.2 -4.9 -4.6 -2.7 -2.3 DC8YZ +0.1 +0.2 -0.1 +0.2 +0.1 +0.1 +0.1 +0.2 +0.1 +0.1 DD5XX -1.4 -0.8 -0.8 +0.2 +0.3 +0.2 -0.1 -0.5 -0.3 -0.1 DE1LON -0.1 -0.1 +0.1 +0.2 +0.4 +0.6 +0.2 +0.2 +0.3 +0.3 DF2CK -0.1 +0.1 +0.2 +0.5 +0.9 +0.9 +0.2 +0.4 +0.4 +0.8 DF7GB -0.0 +0.0 +0.1 -0.0 -0.0 -0.0 -0.0 +0.1 -0.0 -0.0 DJ2BC -0.2 -0.3 -0.1 -0.1 -0.0 -0.1 -0.2 +0.2 -0.3 -0.3 DJ9IE +0.0 -0.0 -0.1 +0.2 +0.1 -0.2 +0.0 -0.1 +0.0 +0.2 DK0TE +0.4 -0.2 -0.0 +0.6 +2.0 +2.1 +1.0 +0.8 +0.8 +0.9 DK3UA -8.6 -8.7 -10.0 -8.5 -5.3 -6.1 -8.3 -10.4 -8.3 -7.9 DK3WW +0.9 DK8NE +0.0 DK9IP -0.1 -0.1 +0.1 +0.1 +0.0 +0.0 +0.0 +0.1 -0.1 -0.0 DK9IP-1 +0.1 +0.1 +0.1 +0.1 +0.1 +0.1 +0.1 +0.2 +0.1 +0.1 DL0LA +0.2 +0.2 +0.1 +0.3 +0.2 +0.2 +0.2 +0.3 +0.2 +0.2 DL0PF -0.1 +0.1 +0.1 +0.5 +0.5 +0.5 +0.2 +0.6 +0.7 +0.6 DL1AMH +0.6 DL1AMQ -1.7 DL1EFW +1.0 +1.0 +0.6 +1.5 +0.5 +12.8 +15.0 +14.5 +14.6 DL1HWS +0.3 +0.4 +0.2 +0.4 +0.4 +0.5 +0.3 +0.4 +0.4 +0.3 DL8LAS -0.1 +0.2 +0.1 +0.3 +0.3 +0.3 +0.2 +0.3 +0.3 +0.3 DL8TG +0.1 +0.0 +0.1 +0.0 -0.0 +0.0 +0.0 +0.1 -0.0 +0.1 DL9GTB +0.0 -0.5 -0.9 DM5GG +0.7 -0.4 +1.0 +0.8 +0.6 +0.7 -0.3 DM6EE +0.0 +0.1 +0.2 +0.1 +0.1 DR4W -3.3 -3.0 -3.0 -1.3 -2.0 -1.8 -1.9 -1.6 -1.5 -0.8 DR5X +0.5 +0.3 E28AC +4.7 +4.8 +4.7 +4.8 +4.3 +5.1 +4.2 EA1RX -2.4 -6.9 -10.5 -9.5 -5.8 -2.6 -3.7 EA1URA +0.7 +1.2 +0.7 +1.2 +1.9 +1.7 +1.4 +0.5 +0.5 -0.0 EA2CW +0.5 +0.5 +0.6 +0.8 +1.0 +1.1 +0.6 +0.6 +0.5 +0.4 EA2RCF-4 +0.6 +0.7 +0.6 +0.8 +0.8 +0.4 +0.5 +0.4 +0.3 EA4FIT +0.0 +0.0 +0.0 +2.4 +0.0 EA5RQ/A +0.0 -0.1 +0.5 +0.0 +0.0 -0.0 +0.0 -0.1 +0.2 +0.4 ES2RR -0.1 -0.0 -0.2 -0.1 -0.0 -0.1 -0.1 -0.0 -0.0 -0.1 F4VVG -0.4 -0.3 -0.1 -0.0 -0.5 -0.3 F6IIT -1.0 -0.5 -0.7 -0.5 -0.6 -0.6 -0.7 -0.8 -0.8 -0.7 F8DGY +0.1 +0.1 +0.2 -2.7 +0.3 +0.6 +0.2 +0.1 +0.2 +0.1 G0KTN +0.3 +0.3 +0.3 +0.3 +0.4 +0.4 +0.3 +0.3 +0.2 +0.2 G3XBI +0.3 +0.2 +0.2 +0.0 +0.2 +0.3 +0.1 +0.5 +0.2 +1.4 G3YPP +0.2 +0.1 +0.2 +0.3 +0.1 +0.2 +0.1 +0.3 +0.0 +0.0 G4AON +1.0 G4IRN +0.6 +0.6 +0.5 +0.5 +0.6 +0.7 +0.5 +0.4 +0.6 +0.4 G4ZFE +0.2 +0.2 +0.2 +0.3 +0.3 +0.6 +0.4 +0.5 +0.3 +0.3 GI4DOH +0.3 +0.3 +0.1 +0.2 +0.4 +0.3 +0.3 +0.3 +0.4 +0.3 HA1VHF -1.1 -1.9 -1.4 -0.6 -0.9 -0.9 -0.9 -1.0 -1.1 +0.0 HA2NA-5 +0.6 +0.1 +0.4 +0.6 +0.6 +0.4 +0.6 +0.3 HA6PX -0.1 -0.1 -0.0 -0.0 +0.0 -0.0 -0.0 -0.1 -0.1 -0.1 HA8TKS +0.2 +0.2 +0.3 +0.2 +0.3 +0.3 +0.3 +0.1 +0.2 +0.2 HB9BXE +0.1 +0.0 +0.2 +0.2 +0.2 +0.3 +0.2 +0.4 +0.2 +0.2 HB9DCO -0.5 -0.5 -0.3 -0.3 -0.3 -0.4 -0.4 -0.3 -0.4 -0.4 HG0Y +5.7 +6.0 +6.2 +8.2 +7.6 +8.1 +8.0 +7.2 HG5FMV +0.2 +0.2 +0.0 -1.1 +0.4 HG8A +0.0 +0.2 +0.4 +0.8 +0.6 +0.6 +0.5 +0.4 +0.6 +0.6 IK3STG +1.6 +1.9 +1.4 +2.1 +2.7 +2.9 +2.2 +2.2 +2.3 +2.1 IK4VET +1.5 +2.3 +2.8 +3.3 +3.6 +3.5 +2.8 +1.9 +1.7 +2.5 IK7YTT -0.7 IU2RPU +0.0 -1.1 -1.7 -1.6 -10.7 IZ2CPS +1.0 +0.9 +0.5 +0.7 +1.2 +0.8 +0.5 +0.8 +1.0 +0.2 J68HZ +11.5 +11.7 +12.0 +11.8 +11.2 +11.1 +11.0 +11.5 +12.2 JH7CSU1 +2.9 +2.5 +2.6 +2.9 +3.4 +3.1 +2.0 +1.9 +2.0 +3.2 JI1HFJ -1.7 -8.5 +0.1 -1.6 -0.9 -2.8 -8.6 -4.1 -3.8 -1.9 JJ2VLY +0.4 +0.9 +0.2 +1.0 +2.9 +1.8 -0.6 +0.1 +1.0 +0.9 JN1ILK -0.1 +0.4 +0.1 +0.5 +0.8 +0.4 +0.2 +0.2 -0.9 -0.5 K1RA +0.7 +0.6 +0.7 +0.5 +0.2 +0.3 +0.2 K2PO/7 +0.7 +0.6 +0.2 K3PA-1 +0.0 -0.1 -0.0 -0.0 -0.0 -0.0 +0.0 -0.1 +0.0 -0.0 K3PA-2 -1.1 -0.6 -0.6 -1.2 -0.8 -1.4 -2.3 -1.1 -0.4 -2.0 K4PP +0.9 +1.0 +0.9 +0.6 +0.6 +0.0 +0.1 +0.4 +0.3 K5EM -0.0 +0.0 -0.1 -0.0 -0.1 +0.1 +0.1 +0.2 K5TR +0.9 +1.0 +0.3 +1.1 +0.4 +0.7 +0.7 +0.5 +0.8 +0.5 K6FOD +0.0 +0.0 +0.1 -0.2 -0.1 -0.1 +0.0 +0.1 -0.0 -0.2 K7EK +0.9 +1.1 +0.5 +0.4 +0.4 +0.2 +0.0 +0.7 +0.7 +0.5 K7MJG +0.7 +0.4 +0.1 -0.0 +0.2 -0.0 +0.1 +0.4 +0.4 +0.0 K7RUT -1.3 K9IMM -0.0 +0.2 -0.0 +0.0 +0.0 +0.0 +0.1 +0.0 +0.1 +0.0 K9LC +0.0 +0.1 +0.2 +0.0 +0.1 +0.1 +0.0 +0.0 +0.1 +0.0 KA7OEI +0.3 +0.3 +0.2 +0.3 +0.3 +0.2 +0.1 +0.2 +0.4 +0.1 KC2LRC +0.7 KC4YVA +5.4 +5.6 +4.4 +4.8 +5.2 +5.3 +4.8 +4.5 +5.2 +4.7 KD2OGR +0.5 +0.4 +0.2 KH6LC +0.6 +0.3 +0.4 +0.2 +0.3 +0.2 +0.5 +0.3 +0.2 +0.5 KM3T +0.0 -0.1 -0.2 -0.0 -0.0 -0.0 -0.0 -0.2 -0.1 +0.0 KM3T-2 +0.4 +0.3 +0.5 +0.4 +0.4 +0.4 +0.2 +0.4 +0.3 +0.2 KM3T-3 +0.3 +0.2 +0.3 +0.2 +0.3 +0.2 +0.2 +0.3 +0.3 +0.2 KO7SS -0.6 -0.9 -0.9 -0.8 -0.7 -0.7 -0.7 -1.0 -1.0 -1.1 KP3CW +0.3 +0.3 +0.3 +0.3 +0.4 +0.4 +0.3 +0.3 +0.4 +0.3 KV4TT -0.1 +0.0 +0.0 -0.1 -0.1 -0.2 +0.2 +0.2 +0.2 +0.1 LA6TPA -2.9 -2.7 -3.0 -2.5 -2.3 -2.0 -2.8 -2.8 -1.8 -1.6 LA7GIA -0.1 -0.1 +0.0 +0.0 -0.1 LB9KJ -1.3 -0.9 -1.5 -1.1 -9.6 LU3MG +0.0 LU8XW -1.9 -0.6 -1.0 -1.3 -1.4 -1.8 -1.3 -2.8 -2.4 -2.4 LY2XW +0.5 +0.5 LY3G +0.3 -5.1 LZ3CB -0.1 -0.0 -0.0 +0.0 -0.1 -0.0 -0.1 +0.1 -0.1 +0.0 LZ4AE +3.5 +3.3 +3.1 +3.1 +3.8 +3.5 +2.8 +3.6 +3.2 LZ4UX +0.0 -0.1 -0.1 -0.0 -0.1 -0.0 +0.0 -0.0 +0.0 -0.0 LZ5DI +0.5 +0.7 +0.5 +0.6 +0.7 +0.8 +0.4 +0.5 +0.6 +0.5 LZ7AA +0.6 +0.7 +0.7 +1.0 +0.7 +0.6 +0.5 +0.7 +0.8 +0.6 M0JYE -11.1 -11.0 -11.0 MM0ZBH +0.2 +0.1 -0.3 -0.2 +2.3 +1.4 +0.7 +0.1 +0.1 -0.4 MM3NDH +0.0 +0.0 +0.0 +0.0 +0.1 +0.1 +0.0 -0.1 +0.0 -0.0 MW0MUT +0.2 +0.0 +0.2 +0.1 +0.3 +0.1 +0.1 +0.2 +0.1 +0.2 N0OI +0.5 +0.3 +0.0 -0.3 -0.2 -0.1 +0.3 +0.3 +0.3 +0.1 N2QT +0.3 +0.1 +0.3 +0.2 -0.0 +0.0 +0.1 -0.0 -0.1 -0.0 N4ZR +0.1 +0.0 +0.1 +0.0 +0.0 +0.1 +0.4 +0.4 +0.3 N6TV +0.6 +0.4 +0.4 +0.3 +0.1 +0.1 +0.4 +0.7 +0.5 +0.2 N7TUG +14.3 +13.9 +14.2 +14.2 +13.9 +13.8 +14.1 +14.4 +14.1 +14.3 N9CO +0.1 +0.3 -0.1 -0.0 -0.1 -0.0 +0.0 +0.2 -0.1 +0.1 ND7K -1.2 -1.2 -1.1 -1.6 -1.1 -1.3 -1.2 -1.4 -1.4 NG7M -0.4 -0.2 -0.4 -0.3 -0.2 -0.2 -0.4 -0.3 -0.4 -0.4 NN3RP +0.9 +0.4 +0.8 +0.3 +0.1 +0.2 +0.1 +0.4 +0.2 +0.0 NT6Q +4.0 +2.7 +2.6 +3.2 +3.5 +3.7 +2.3 +3.0 +3.3 +2.8 NU6XB +0.3 +0.3 +0.5 +0.5 +0.2 +0.5 +1.0 +0.7 +0.6 +0.5 OE6ADD +0.2 +0.1 +0.0 +0.2 +0.2 +0.2 +0.1 +0.2 +0.2 +0.2 OE6TZE +0.1 +0.1 +0.0 +0.2 +0.1 +0.1 +0.1 -0.3 -0.0 +0.1 OE9GHV -0.1 -0.1 -0.0 -0.0 -0.0 -0.0 -0.1 +0.1 -0.1 +0.0 OG66X +0.0 -0.1 -0.3 +0.1 +0.1 +0.2 +0.0 +0.0 -0.1 OG73X +1.4 OH4KA +0.2 +0.4 +0.5 +0.4 +0.4 +0.6 +0.5 OH6BG +4.5 +5.0 +5.0 +4.7 +4.6 +3.8 +4.1 +4.0 +3.8 +5.0 OH8KA -5.2 -1.1 +2.9 +2.9 OK1HRA -4.3 -3.9 -3.4 -3.5 -3.9 -4.1 -3.8 -3.8 -3.9 -3.6 OK4QRO +1.4 +1.5 +1.1 +1.7 +2.0 +2.0 +1.5 +1.5 +1.5 +1.4 ON4EM -0.8 +0.4 ON6ZQ -0.3 -0.3 -0.3 -0.1 -0.0 +0.1 -0.1 -0.2 -0.3 -0.0 ON7KEC +0.8 +0.0 OZ1AAB +0.0 -0.1 -0.0 -0.0 -0.1 -0.1 -0.0 +0.0 +0.1 +0.0 OZ1BZS -0.0 +0.1 +0.1 +0.1 +0.1 +0.1 +0.4 +0.2 OZ4ADX +0.3 +0.1 -0.0 +0.2 +0.2 +0.2 +0.1 -0.0 +0.0 +0.4 P40L +1.2 +0.8 +0.7 +0.7 +0.3 +0.4 +0.2 PA0MBO +0.3 +0.3 +0.2 +0.4 +0.5 +0.6 +0.2 +0.3 +0.4 +0.3 PA8MM -0.1 -0.1 -0.4 +0.0 +0.2 -1.2 -3.8 -3.4 -4.0 PC5Q +0.3 PE5TT -0.3 +0.1 -0.1 -0.0 +0.3 +1.0 +0.3 +0.2 +0.6 +0.4 PJ2A +0.0 -0.4 -0.5 -0.7 -0.1 -0.6 -0.2 R1LB +0.0 +0.0 -0.1 +0.1 -0.1 -0.0 -0.2 -0.0 -0.1 +0.0 R6YY +0.4 +0.2 -0.1 -0.2 -0.2 -0.2 -0.1 -0.1 +0.2 +0.0 RK3TD +0.8 +0.4 +0.1 +0.2 +0.2 +0.2 +0.1 +0.1 +0.3 +0.3 RK3TD-2 +0.4 +0.4 +0.3 +0.4 +0.6 +0.5 +0.4 +0.7 +0.9 +0.8 RN4WA +0.9 +1.0 +0.9 +1.0 +1.2 +1.3 +0.9 +0.8 +1.1 +1.0 RU9CZD -3.6 -5.0 -6.8 -6.7 -7.2 -4.9 +4.8 +11.7 +10.7 +11.1 RW9AV -0.8 -1.0 -0.7 -0.8 -0.6 S50U +0.1 +0.0 +0.1 +0.1 +0.1 +0.1 -0.0 +0.2 -0.0 -0.1 S53A +1.4 +1.3 +1.1 +1.6 +1.9 +1.8 +1.4 +1.3 +1.4 +1.4 S53WW -0.6 -0.4 -0.0 +0.3 +0.1 +0.1 +0.1 -0.1 +0.2 +0.1 SE5E +0.1 +0.1 +0.1 +0.2 +0.3 +0.2 +0.1 +0.1 +0.2 +0.2 SM0TCZ -3.6 -2.5 -4.9 -0.2 -4.8 SM7IUN -0.0 +0.0 -0.1 +0.0 -0.1 -0.1 -0.2 -0.2 -0.2 +0.1 SP8R +0.0 SQ5J +3.6 +3.7 +3.2 +3.8 +4.1 +4.1 +3.9 +4.9 +4.9 SQ5OUO +5.9 +5.9 +5.2 +5.8 +6.0 +6.0 +6.5 +6.0 +6.5 +6.1 SV1CDN -0.4 -0.8 -1.1 -0.7 -0.9 -0.9 -1.2 -1.3 -0.7 -0.7 SZ1A -0.4 -0.3 -0.6 +0.3 +1.6 +0.8 -0.3 -0.5 -0.5 +0.0 TF3Y +1.2 +1.2 +1.1 +1.2 +1.5 +1.5 +1.2 +1.3 +1.1 TF4M -1.3 -1.2 -1.2 -1.6 -1.6 -1.5 -2.3 -1.9 -1.3 -1.6 TI7W -0.4 -0.3 -0.3 -0.3 -0.3 -0.3 -0.3 -0.4 -0.2 -0.4 TZ4AM +0.6 -6.4 -3.0 +0.0 +0.0 +0.3 -2.0 UA0S +1.1 +1.4 +1.2 +1.2 +0.7 +0.8 +0.8 +0.8 +1.2 +0.9 UD4FD +0.8 +0.6 +0.3 +0.3 +0.5 +0.2 +0.5 +0.4 +0.5 +0.3 UY2RA +1.8 +1.8 +1.0 +1.5 +2.0 +2.0 +1.6 +1.8 +2.3 +1.7 V51YJ +1.8 +2.3 +2.2 +1.3 +1.4 +1.8 +1.0 +0.9 +1.3 +1.7 VE6AO -1.8 -2.0 -0.8 -0.7 -1.3 -1.2 -1.3 -1.1 -1.3 -0.9 VE6JY +0.2 +0.6 +1.4 +0.4 +3.3 +2.4 +0.2 +3.5 +3.9 +0.4 VE6WZ -1.2 -5.8 -7.8 -5.6 -5.6 -4.4 -5.2 -8.0 -13.6 -6.7 VE7CC +0.6 +0.6 +0.4 +0.5 +0.8 +0.8 +0.4 +0.3 +0.8 +0.7 VE7XMC +15.5 VK2EBN +0.0 +0.0 -0.4 +0.0 +0.0 VK2GEL +4.4 +3.3 +4.2 +4.6 +4.2 +3.9 +4.2 +3.1 +3.9 +2.3 VK2RH -0.1 -0.2 +0.0 +0.1 +0.0 +0.1 +0.2 +0.1 -0.9 +0.0 VK3RASA -0.8 -0.4 -0.7 -0.1 -0.2 -1.4 -0.6 -0.7 -0.9 -0.4 VK6ANC -0.9 -0.5 -1.0 -0.9 -1.0 -1.2 -0.9 -1.1 -0.9 -0.7 VR2FUN-74 +6.0 +6.3 +6.5 +6.1 +6.4 +6.4 +6.2 +6.1 +6.4 +6.3 VR2FUN-77 +0.1 -0.1 +0.2 -0.1 +0.0 +0.2 -0.3 -0.1 -0.1 VU2CPL +3.2 +2.8 +2.2 +3.3 +3.1 +3.3 +2.6 +2.6 +2.9 +2.7 VY0ERC +0.0 +0.0 +0.7 +0.5 +1.5 +0.9 +0.9 +1.5 +0.5 W1NT-2 +0.4 +0.3 +0.4 +0.3 +0.4 +0.3 +0.3 +0.2 +0.3 +0.3 W1NT-6 +0.3 +0.2 +0.3 +0.3 +0.3 +0.3 +0.3 +0.2 +0.3 +0.3 W1UE -5.3 -5.8 -5.4 -5.3 -5.2 -5.2 -0.9 -2.8 -5.7 -8.9 W2MV +0.5 +0.5 +0.6 +0.6 +0.3 +0.2 +0.2 +0.1 -0.2 -0.1 W2NAF +1.2 +1.3 +0.9 +1.1 +1.2 +1.2 +0.9 +1.0 +1.0 +1.1 W3LPL -4.0 -3.3 -3.0 -3.5 -3.8 -3.9 -4.1 W3OA -0.0 +0.1 +0.0 +0.0 +0.0 -0.1 -0.1 +0.0 +0.0 -0.1 W3UA -0.1 -0.0 +0.0 -0.1 -0.0 -0.1 -0.1 +0.0 -0.1 -0.1 W4AX +4.6 +4.9 +4.6 +4.6 +4.8 +4.1 +4.2 +4.7 +5.0 +3.9 W4KAZ -0.4 -0.4 -0.2 -0.8 -0.8 -1.1 W6BB +0.5 +0.6 +0.6 +0.6 +0.3 +0.5 +0.4 +0.4 +0.9 +0.1 W6YX +0.3 +0.1 +0.0 -0.2 -0.3 -0.2 +0.1 +0.1 +0.0 -0.1 W8WTS +0.2 +0.0 +0.1 +0.2 +0.1 +0.1 +0.1 -0.0 -0.1 -0.1 W8WWV -1.4 -1.4 -1.1 -1.4 -1.7 -1.7 -1.7 -1.7 -1.4 -1.2 WA7LNW +0.1 -0.1 -0.4 -0.3 -0.1 -0.1 +0.0 -0.3 -0.5 -0.8 WB6BEE +0.1 +0.2 -0.1 -0.0 -0.0 +0.0 -0.1 -0.1 -0.0 +0.1 WC2L +0.2 +0.4 +0.0 +0.1 +0.1 +0.2 +0.1 +0.2 +0.2 -0.1 WC8GOP +3.5 +6.4 +2.6 +5.8 +5.5 +5.7 +4.9 +2.9 +6.3 +5.5 WE9V -0.1 -0.1 +0.5 +0.1 +0.1 -0.2 -0.2 -0.1 -0.1 +0.1 WF7U +1.9 +4.0 +11.2 +1.4 +4.6 +2.7 WS3W -0.4 WV4P +0.7 +0.7 +0.6 +0.3 +0.4 +0.4 +0.3 +0.5 +0.7 +0.3 WZ7I +0.1 -0.1 +0.0 +0.0 -0.0 -0.1 -0.0 -0.2 -0.0 -0.1 XV9Q +0.0 +0.0 +0.0 +0.0 -0.0 +0.0 +0.0 +0.0 YO2MAX +6.0 +5.9 +5.5 +6.0 +5.9 +5.7 +5.3 +5.0 +5.5 +5.3 YO4RDW +0.5 +0.7 +0.4 +0.5 -6.6 -6.3 -7.0 -9.7 -11.0 -1.9 YU7GM +0.4 +0.4 +0.4 +0.6 +0.3 +0.6 +0.1 ZF9CW -0.6 -0.4 -0.3 -0.6 -0.7 +0.4 +0.5 +0.2 +0.6 +0.5 ZL3X -0.8 -0.9 -0.2 -0.2 -0.4 -1.3 -1.1 -0.4 +0.4 ZL4YL +1.3 +1.4 +0.6 +0.7 +1.6 +1.8 +1.0 +1.3 +1.9 +1.3 Last updated 2024-04-19 00:15:51 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 2024-04-19 00:15:51 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.