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 here is based on archived RBN data from the previous day, UTC time. When making adjustments, this means that changes in calibration will not have full impact on the listed data until the second day after the change.
The deviation estimates listed below are based on spots on all active bands 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.
The software used to calculate the tables below can be found here. It runs as a cron job in an Ubuntu container on my server and uploads to this WordPress site ten minutes after midnight UTC every night.
The calculation of deviation estimates is done in two stages. The first stage uses a small number of highly accurate skimmers (called “anchor skimmers” in the code) as reference skimmers. The whole estimation process is then repeated but using the anchor skimmers plus all skimmers with 0.2ppm or less deviation from the anchors as reference skimmers. This way the number of qualifying spots is drastically increased, leading to much more reliable estimates for all skimmers. All skimmers used as reference skimmers in the second stage are marked with an asterisk in the table below.
Due to propagation characteristics and statistical variations 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.
292182 RBN spots between 2020-10-23 00:00 and 23:59 UTC. 68122 spots (23.3%) were from reference skimmers (*). Average spot flow was 203 per minute from 161 active CW skimmers. 142929 spots from 157 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 30s. * 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 ------------------------------------- 3B8CW* -0.0 231 0.999999952 3V/KF5EYY -3.1 194 0.999996949 4X6HP +2.7 485 1.000002704 7K1JRC -2.4 12 0.999997625 9A1CIG +6.8 361 1.000006836 9V1RM -2.1 52 0.999997900 AC0C* -0.2 241 0.999999823 AC0C-2 -0.1 285 0.999999950 BA7PC -7.9 161 0.999992098 BA7QT* -0.0 70 1.000000000 BG4GOV -0.7 115 0.999999276 BY1CY +0.0 30 1.000000000 CT7ANO -0.5 26 0.999999453 CX6VM* +1.0 612 1.000000957 DD5XX +0.3 1842 1.000000321 DE1LON -1.9 2354 0.999998065 DF4XX* -0.0 1495 0.999999995 DF7GB* -0.1 1630 0.999999881 DJ2BC -0.4 1653 0.999999597 DJ9IE-1 +0.0 13 1.000000000 DK0TE +2.0 1890 1.000002027 DK3UA +6.0 483 1.000006021 DK3WW -4.1 138 0.999995887 DK9IP* +0.0 1917 1.000000011 DL0PF +2.0 2788 1.000001970 DL1AXX +4.6 483 1.000004551 DL3DTH* +0.0 2503 1.000000021 DL8TG -1.2 2403 0.999998848 DL9GTB +1.0 1846 1.000000973 DM7EE* -0.0 1662 0.999999970 DO4DXA* +0.2 1178 1.000000206 DR4W -6.3 3203 0.999993686 DU3TW +0.2 43 1.000000230 EA5WU -0.6 3223 0.999999423 EA8/DF4UE -1.2 3092 0.999998792 ET3AA +14.4 135 1.000014434 F6IIT -0.5 3231 0.999999503 F8DGY -2.6 766 0.999997392 G0LUJ +2.6 927 1.000002585 G4AON +0.6 140 1.000000599 G4ZFE* -0.1 2302 0.999999904 GI4DOH +0.3 1006 1.000000296 GM6DX +0.8 214 1.000000799 HA1VHF* +0.0 1510 1.000000003 HA6PX* -0.2 751 0.999999827 HA7GN -0.5 183 0.999999454 HB9BXE* +0.2 1126 1.000000196 HB9DCO -4.6 1555 0.999995444 HB9JCB +1.1 2107 1.000001136 HS8KVH +3.6 248 1.000003629 IK3STG* -0.2 1234 0.999999847 IK4VET-1 +0.6 2554 1.000000650 IZ2CPS -1.0 712 0.999999036 JA4ZRK -0.0 37 0.999999999 JG1VGX -0.9 38 0.999999061 JH7CSU1 +2.5 339 1.000002451 JI1HFJ +1.6 27 1.000001596 JJ2VLY* +0.1 142 1.000000135 JK4USW -0.1 201 0.999999907 JQ1BVI* -0.0 195 0.999999959 K1TTT -1.7 835 0.999998332 K2DB +0.8 823 1.000000822 K2PO/7 +0.8 594 1.000000799 K3PA* -0.0 1272 0.999999953 K7EG +0.4 324 1.000000416 K7FYI +0.6 357 1.000000603 K7RUT +14.8 206 1.000014802 K9IMM* -0.2 832 0.999999835 K9LC -0.3 900 0.999999652 K9TM-4* +0.2 1018 1.000000154 KC0VKN +0.4 96 1.000000446 KC4YVA +3.3 249 1.000003302 KD2OGR* -0.1 257 0.999999917 KD7YZ +4.1 70 1.000004130 KH6LC -1.0 202 0.999999011 KI4PAD -0.5 609 0.999999549 KM3T* +0.0 2279 1.000000022 KM3T-2* -0.1 2078 0.999999927 KO7SS -0.9 1430 0.999999099 KO7SS-7 +1.0 836 1.000001020 KQ8M +2.1 334 1.000002087 LA6TPA -0.2 618 0.999999827 LZ3CB* -0.3 1162 0.999999712 LZ4AE* +0.2 1912 1.000000187 LZ4UX* -0.0 1341 0.999999969 LZ7AA* -0.0 1392 0.999999957 MW0MUT +1.1 2249 1.000001135 N0OI +4.7 426 1.000004692 N4ZR* +0.1 626 1.000000052 N5RZ -1.4 1137 0.999998603 N6TV +0.7 296 1.000000697 N6WIN-7 -1.2 901 0.999998848 N7TUG -0.7 60 0.999999287 N8AI -2.1 51 0.999997854 NC7J* +0.3 438 1.000000258 NN3RP -0.5 125 0.999999545 OE9GHV* -0.0 2859 0.999999965 OG66X* -0.4 1265 0.999999562 OG73X +0.0 159 1.000000045 OH4KA +5.9 111 1.000005906 OH6BG +0.6 1705 1.000000587 OK2EW +0.7 3545 1.000000716 OL7M -1.7 2509 0.999998343 ON6ZQ +0.7 2227 1.000000711 OZ5W +3.9 29 1.000003937 PA0MBO* +0.1 684 1.000000147 PA3AIN +0.7 158 1.000000722 PA8MM -0.5 265 0.999999462 PJ2A -2.2 267 0.999997794 PY1CG -0.7 229 0.999999345 R6YY -3.0 354 0.999996998 RN4WA +7.7 324 1.000007716 RU9CZD +1.1 813 1.000001114 S50ARX +1.2 687 1.000001160 S50U +1.0 709 1.000000951 SE5E -0.3 2672 0.999999663 SJ2W +0.6 2787 1.000000577 SM0TCZ -7.1 6 0.999992877 SM6FMB +4.0 1630 1.000003984 SM7IUN* +0.0 491 1.000000029 SV8RV +2.2 232 1.000002212 SZ1A -3.8 1669 0.999996225 TF3Y -0.8 363 0.999999227 TF4X -2.5 3156 0.999997523 UA4M +3.8 1932 1.000003782 UY2RA* +0.3 484 1.000000300 V51YJ +0.9 159 1.000000882 VE2WU -0.8 534 0.999999172 VE3NZ* +0.3 634 1.000000326 VE6AO -2.8 139 0.999997223 VE6WZ +1.2 715 1.000001184 VE7CC* -0.0 155 0.999999969 VK4CT -0.7 346 0.999999259 VK6ANC -0.7 183 0.999999254 VU3KAZ -0.4 127 0.999999570 W1NT-2 -0.8 710 0.999999212 W1NT-6 -0.9 2862 0.999999146 W2LB -12.6 152 0.999987376 W2MV* +0.3 409 1.000000314 W3LPL +1.2 1905 1.000001228 W3OA* -0.3 1354 0.999999747 W3RGA +0.2 1049 1.000000233 W3UA +2.1 2257 1.000002058 W4AX +2.5 141 1.000002488 W4KAZ -1.4 1013 0.999998608 W7HR +16.1 147 1.000016063 W8WTS -0.8 715 0.999999229 W8WWV +0.7 948 1.000000718 W9XG +4.0 571 1.000003981 WA3OPY +12.3 16 1.000012306 WA7LNW +10.5 669 1.000010527 WA9VEE -2.0 7 0.999997969 WB6BEE* +0.0 745 1.000000035 WC2L -0.1 147 0.999999871 WE9V -1.0 1040 0.999998984 XQ3OP +0.9 16 1.000000891 ZL3X +12.2 7 1.000012232 Last updated 2020-10-24 00:10:11 UTC
Historical skimmer frequency accuracy
Below you will find historical accuracy data for the past five 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 20-10-23 20-10-22 20-10-21 20-10-20 20-10-19 ------------------------------------------------------------- 3B8CW -0.0 +0.0 +0.3 +0.2 +0.2 3V/KF5EYY -3.1 -2.7 -2.9 -3.0 -3.0 4X6HP +2.7 +3.1 +3.7 +2.8 +3.2 7K1JRC -2.4 -0.4 9A1CIG +6.8 +6.5 +6.2 +6.8 +6.1 9V1RM -2.1 -1.1 -1.5 -2.5 -2.4 AA4VV +0.0 AC0C -0.2 -0.0 -0.0 +0.0 -0.1 AC0C-2 -0.1 -0.0 +0.0 -0.0 +0.0 BA7KW -0.2 +0.7 +0.6 +0.2 BA7PC -7.9 -8.9 -7.6 -9.8 -10.4 BA7QT -0.0 +0.1 -0.7 +0.0 +0.0 BD7LMD -5.2 -7.4 -7.2 BG4GOV -0.7 -0.8 -1.9 -1.0 -0.0 BG8FT +13.3 +12.5 +13.9 BH1VCS -1.8 BH4RRG +0.0 BY1CY +0.0 +0.4 -1.0 +0.0 +0.0 CT7ANO -0.5 -1.2 -1.2 -1.1 CX6VM +1.0 +0.8 +0.9 +1.2 +0.9 DD5XX +0.3 +0.3 +0.3 +0.3 +0.4 DE1LON -1.9 -1.8 -1.9 -2.2 -1.9 DF0RW -0.3 -0.3 DF4XX -0.0 +0.2 +0.1 +0.2 +0.3 DF7GB -0.1 -0.1 -0.0 +0.1 +0.1 DJ2BC -0.4 -0.4 -0.4 -0.2 -0.3 DJ9IE-1 +0.0 +0.0 +0.0 +0.0 DK0TE +2.0 +1.8 +1.8 +1.6 +1.7 DK3UA +6.0 +6.1 +6.3 +6.3 +6.2 DK3WW -4.1 -4.2 DK9IP +0.0 -0.0 +0.0 +0.2 +0.0 DL0PF +2.0 +1.8 +1.9 +1.6 +1.6 DL1AXX +4.6 +4.3 +4.1 +4.0 +3.7 DL3DTH +0.0 -0.0 +0.1 -0.0 +0.1 DL7NX -1.2 -0.7 DL8TG -1.2 -1.0 -1.0 -0.9 -1.0 DL9GTB +1.0 +0.8 +1.1 +0.7 +1.0 DM7EE -0.0 -0.1 +0.0 +0.1 +0.3 DO4DXA +0.2 +0.1 +0.3 +0.3 +0.3 DR4W -6.3 -7.1 -7.4 -8.4 -7.4 DU3TW +0.2 +0.3 +0.0 +0.5 +0.6 EA5WU -0.6 -0.6 -0.4 -0.6 -0.7 EA8/DF4UE -1.2 -0.9 -0.7 -0.3 -0.8 ES3V -1.5 -0.2 -0.1 ET3AA +14.4 F4VSQ +8.4 +5.0 F5AHD -1.3 -1.9 -1.1 F6IIT -0.5 -0.6 -0.7 -0.9 -0.9 F8DGY -2.6 -2.1 -2.2 -1.7 -3.9 G0LUJ +2.6 +3.8 +4.8 +4.5 +2.9 G4AON +0.6 +0.9 +0.9 +1.2 G4HSO +0.9 +0.7 +0.2 +0.6 G4ZFE -0.1 -0.0 +0.1 +0.1 +0.2 GI4DOH +0.3 +0.3 +0.6 +0.4 +0.4 GM6DX +0.8 +0.6 +0.8 +1.0 +0.8 HA1VHF +0.0 +0.1 +0.2 +0.0 +0.2 HA5PP-3 +0.9 +1.5 +0.6 HA6PX -0.2 -0.3 -0.3 -0.3 -0.6 HA7GN -0.5 -0.1 -0.5 -0.2 HB9BXE +0.2 +0.3 +0.4 +0.4 +0.6 HB9DCO -4.6 -4.7 -4.7 -4.8 -5.1 HB9JCB +1.1 +1.2 +1.5 +1.1 +1.4 HS8KVH +3.6 +3.2 +3.0 +3.4 +3.0 IK3STG -0.2 -0.4 -0.1 -0.1 -0.0 IK4VET-1 +0.6 +0.8 +1.1 +0.8 +1.0 IZ2CPS -1.0 -1.5 -1.3 -1.4 -1.3 JA4ZRK -0.0 -0.7 -0.1 +0.0 +0.7 JG1VGX -0.9 +0.0 -1.0 -0.7 -0.5 JH7CSU1 +2.5 +1.9 +2.1 +4.0 +1.6 JI1HFJ +1.6 +1.0 +2.6 JJ2VLY +0.1 -0.1 -0.9 -0.6 -1.4 JK4USW -0.1 +0.2 +0.7 +0.0 JQ1BVI -0.0 -0.2 -0.3 +0.0 +0.0 JR1BFZ -2.8 -2.2 -5.5 -4.4 K1TTT -1.7 -1.6 -1.5 -1.6 -1.5 K2DB +0.8 +0.6 +1.4 +0.8 +0.5 K2PO/7 +0.8 +1.3 +1.8 +1.1 +1.2 K3PA -0.0 +0.1 +0.0 +0.1 +0.0 K7EG +0.4 +0.6 +0.8 +0.7 +0.8 K7FYI +0.6 +0.9 +0.4 K7RUT +14.8 +15.5 +15.9 +15.4 +15.8 K9IMM -0.2 -0.1 +0.2 -0.1 -0.3 K9LC -0.3 -0.4 -0.6 -0.5 -0.5 K9TM-4 +0.2 +0.4 +0.4 +0.4 +0.4 KC0VKN +0.4 +0.6 +0.0 +0.1 +0.3 KC4YVA +3.3 +4.1 +5.5 +3.4 +3.2 KD2OGR -0.1 +0.2 -0.1 +0.2 +0.1 KD7YZ +4.1 +7.4 +6.6 KH6LC -1.0 +0.2 -0.1 -0.3 -0.0 KI4PAD -0.5 -0.8 -0.6 -0.6 -0.5 KL7RA +15.4 KM3T +0.0 -0.0 -0.0 +0.0 +0.0 KM3T-2 -0.1 +0.0 -0.1 -0.2 -0.3 KO7SS -0.9 -0.4 -0.7 -0.5 -0.3 KO7SS-7 +1.0 +1.2 +1.1 +0.8 +1.2 KQ8M +2.1 +1.6 +1.7 +1.5 +1.2 KU7T -0.1 +0.0 +0.3 LA6TPA -0.2 +0.3 +0.0 -0.1 -0.3 LZ3CB -0.3 -0.1 -0.0 -0.0 +0.0 LZ4AE +0.2 +0.2 +0.2 +0.4 +0.4 LZ4UX -0.0 -0.1 +0.1 +0.1 +0.0 LZ7AA -0.0 +0.2 -0.0 -0.0 -0.1 MW0MUT +1.1 +1.4 +1.6 +1.4 +1.3 N0OI +4.7 +2.4 +5.6 +5.0 +5.1 N4ZR +0.1 -0.1 +0.1 -0.1 -0.0 N5RZ -1.4 -1.2 -1.2 -1.1 -1.0 N6TV +0.7 +0.5 +0.9 +0.4 +0.9 N6WIN-7 -1.2 -0.7 -0.8 -0.9 -1.0 N7TUG -0.7 -1.1 -0.5 -0.3 +0.0 N8AI -2.1 -2.8 -4.3 -1.5 NC7J +0.3 +0.5 +0.7 +0.4 +0.6 NN3RP -0.5 -0.1 +0.1 -0.5 OE9GHV -0.0 -0.0 -0.1 +0.1 +0.1 OG66X -0.4 OG73X +0.0 OH4KA +5.9 +4.6 +4.2 +3.7 +4.3 OH6BG +0.6 +0.4 +0.5 +0.5 +0.5 OK2EW +0.7 +0.9 +1.0 +0.8 +0.9 OL7M -1.7 -1.5 -1.4 -2.1 -2.4 ON6ZQ +0.7 +0.7 +1.0 +0.7 +0.9 OZ5W +3.9 +4.5 +3.7 +2.4 +2.6 PA0MBO +0.1 +0.1 +0.2 +0.2 +0.2 PA3AIN +0.7 +0.6 +1.7 PA8MM -0.5 +0.2 PJ2A -2.2 -2.2 -2.1 -2.6 -2.4 PY1CG -0.7 +0.0 -0.4 -0.2 -0.1 R6YY -3.0 -2.0 -2.0 -0.4 +1.1 RL3A-1 +12.5 +13.4 +14.3 +13.6 RN4WA +7.7 +8.7 +8.2 +7.4 +8.1 RU9CZD +1.1 +1.2 +1.8 +1.4 +1.6 S50ARX +1.2 +1.0 +1.1 +0.6 +0.6 S50U +1.0 +0.9 +1.1 +0.9 +0.7 SE5E -0.3 -0.2 -0.3 -0.3 -0.2 SJ2W +0.6 +0.5 +0.6 +0.6 +0.6 SM0TCZ -7.1 +2.0 SM6FMB +4.0 +0.2 +0.4 +0.3 -0.6 SM7IUN +0.0 -0.1 +0.0 -0.0 +0.0 SV8RV +2.2 +1.8 +2.9 +2.8 +2.6 SZ1A -3.8 -3.6 -4.1 -3.5 TF3Y -0.8 -0.8 -0.8 -0.3 -0.2 TF4X -2.5 -2.1 -1.8 -1.9 -1.9 UA4M +3.8 +3.4 +3.9 +4.3 +3.7 UR6EA +1.1 UY2RA +0.3 +0.6 +0.7 +0.5 +0.4 V51YJ +0.9 +0.8 +0.9 +0.5 +0.7 VE2WU -0.8 -1.5 +0.1 +0.4 -2.5 VE3NZ +0.3 +0.3 +0.2 +0.2 +0.2 VE6AO -2.8 -2.4 -1.7 -1.6 -1.6 VE6WZ +1.2 +1.5 +1.9 +1.2 +1.4 VE7CC -0.0 -0.0 +0.1 +0.3 +0.3 VK3JBL +2.4 +8.6 +11.4 VK4CT -0.7 -1.3 -1.1 -0.8 -0.5 VK6ANC -0.7 -1.2 -1.0 -0.7 -0.5 VU3KAZ -0.4 VY0ERC -5.7 -1.0 -2.1 -1.4 W1NT-2 -0.8 -0.7 -0.8 -0.8 -0.5 W1NT-6 -0.9 -0.7 -0.7 -0.9 -0.7 W2LB -12.6 -14.3 -11.7 -13.6 -13.0 W2MV +0.3 +0.4 +0.5 +1.9 W3LPL +1.2 +1.3 +1.6 +1.2 +1.3 W3OA -0.3 -0.1 -0.2 -0.2 -0.1 W3RGA +0.2 +0.0 +0.1 +0.2 +0.2 W3UA +2.1 +1.9 +2.5 +1.9 +1.8 W4AX +2.5 +4.1 +4.0 +3.2 +3.2 W4KAZ -1.4 -1.1 -1.4 -1.8 -2.0 W7HR +16.1 +17.5 +11.9 +14.1 +12.9 W8WTS -0.8 -1.0 -1.2 -0.8 -0.9 W8WWV +0.7 +0.6 +0.6 +0.2 +0.1 W9XG +4.0 +3.7 +4.2 +4.1 +3.7 WA3OPY +12.3 +14.0 +11.9 +12.4 +12.0 WA7LNW +10.5 +10.8 +10.7 +11.1 +11.0 WA9VEE -2.0 -0.6 +0.0 +0.0 +0.0 WB6BEE +0.0 -0.1 -0.1 +0.0 +0.1 WC2L -0.1 +0.2 -0.5 -0.3 -0.4 WE9V -1.0 -0.9 +12.5 +9.6 -1.0 WZ7I -0.2 -0.1 -0.1 -0.1 XQ3OP +0.9 +4.7 +2.6 +1.8 ZL3X +12.2 +13.8 +12.3 +12.2 ZL4YL +1.1 +1.6 +0.9 Last updated 2020-10-24 00:10:17 UTC
Activity statistics
Summary of unique calls spotted and active skimmers per band and continent.
RBN activity between 2020-10-23 00:00 and 23:59 UTC.
292182 spots with 7829 unique callsigns from 168 active skimmers.
Unique callsigns spotted per continent and band
---------------------------------------------------------------
160m 80m 60m 40m 30m 20m 17m 15m 12m 10m 6m
AF 4 9 0 35 15 21 2 10 9 7 0 79
AS 81 242 2 445 62 203 47 72 14 13 43 891
EU 217 952 122 1742 450 1417 430 550 130 193 17 4421
NA 91 370 33 1109 260 649 202 199 29 61 9 2159
OC 5 13 0 55 16 31 20 6 2 2 2 122
SA 1 9 0 80 12 39 18 29 8 26 0 157
399 1595 157 3466 815 2360 719 866 192 302 71
Active skimmers per continent and band
---------------------------------------------------------------
160m 80m 60m 40m 30m 20m 17m 15m 12m 10m 6m
AF 2 3 1 4 4 5 5 5 3 4 1 5
AS 8 11 1 16 10 15 11 14 5 8 5 17
EU 62 63 19 67 59 63 43 57 19 40 4 75
NA 41 47 10 56 36 50 30 45 17 27 3 61
OC 2 4 0 6 3 5 2 4 1 1 0 6
SA 2 3 0 3 2 3 3 3 1 2 0 4
117 131 31 152 114 141 94 128 46 82 13
Last updated 2020-10-24 00:10:42 UTC