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.
314117 RBN spots between 2021-01-26 00:00 and 23:59 UTC. 64213 spots (20.4%) were from reference skimmers (*). Average spot flow was 218 per minute from 176 active CW skimmers. 142577 spots from 169 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 +0.4 145 1.000000443 3D2AG +0.1 58 1.000000082 3V/KF5EYY +0.3 1173 1.000000316 5W1SA +0.0 20 1.000000000 7N4XCV +1.3 16 1.000001337 9A1CIG +3.9 298 1.000003949 9V1RM -1.3 16 0.999998663 AC0C-1* -0.0 1380 0.999999990 BD7LMD -4.8 48 0.999995244 BD7MLA +1.2 155 1.000001229 BY1CY +1.2 8 1.000001189 CE6MOA -20.2 12 0.999979795 CX6VM +0.1 436 1.000000122 DD5XX +0.5 971 1.000000466 DE1LON -1.6 1267 0.999998431 DF4XX +0.4 876 1.000000359 DF7GB +0.4 1255 1.000000362 DJ2BC* -0.2 1249 0.999999772 DK0TE +1.5 1171 1.000001510 DK3UA +0.5 458 1.000000524 DK3WW +0.3 98 1.000000347 DK9IP +0.3 1270 1.000000322 DL0PF +1.7 1916 1.000001675 DL3DTH +0.7 1614 1.000000689 DL8LAS -2.9 1571 0.999997148 DL8TG* -0.5 785 0.999999545 DL9GTB +0.9 1547 1.000000865 DM6EE -4.2 1573 0.999995826 DM7EE -3.9 1127 0.999996077 DO4DXA* +0.1 576 1.000000140 DR4W* -0.1 1614 0.999999947 E28AC +1.5 124 1.000001515 EA1URA +0.2 1546 1.000000236 EA5WU* +0.1 1984 1.000000148 EA8/DF4UE +0.2 2039 1.000000241 ES3V -0.8 567 0.999999170 ET3AA +0.2 46 1.000000155 F6IIT* -0.2 2341 0.999999751 G0KTN +0.5 1154 1.000000533 G0LUJ -0.8 637 0.999999152 G4AON +1.6 231 1.000001592 G4HSO +0.3 339 1.000000281 G4ZFE +0.4 699 1.000000381 GI4DOH +0.9 808 1.000000895 GM6DX* -0.3 244 0.999999652 HA1VHF -1.0 1160 0.999999002 HA6PX -2.2 1391 0.999997801 HA7GN -0.6 456 0.999999437 HA8TKS +0.5 295 1.000000531 HB9BXE +0.9 764 1.000000910 HB9DCO -24.3 1433 0.999975703 HB9JCB +1.6 1268 1.000001576 HS8KVH +2.8 178 1.000002797 IK3STG -1.3 871 0.999998682 IK4VET-1* +0.0 2029 1.000000021 IZ2CPS -0.9 667 0.999999062 JA4ZRK +0.0 10 1.000000000 JH7CSU1 +2.6 82 1.000002561 JJ2VLY -3.7 66 0.999996327 JQ1BVI +0.3 71 1.000000301 JR1BFZ/2 +0.3 17 1.000000325 K1FC -1.4 21 0.999998649 K1TTT* -0.0 1790 0.999999968 K2DB +0.8 1276 1.000000831 K2PO/7 +0.6 721 1.000000628 K3LR +0.2 1197 1.000000212 K7EG +0.7 467 1.000000677 K7MJG -1.5 237 0.999998474 K9IMM* +0.1 1562 1.000000131 K9LC* +0.2 1373 1.000000206 K9TM-4 +0.7 1179 1.000000665 KC0VKN -0.9 391 0.999999079 KC4YVA +3.8 347 1.000003821 KD2OGR* +0.1 743 1.000000063 KD7YZ* +0.1 1692 1.000000122 KI4PAD -2.3 193 0.999997659 KM3T* +0.1 2453 1.000000087 KM3T-1* +0.3 363 1.000000274 KM3T-2* +0.1 2119 1.000000127 KO7SS -2.8 1759 0.999997198 KO7SS-7* -0.0 901 0.999999961 KP2RUM* -0.1 1143 0.999999871 KU7T* -0.3 1025 0.999999693 KV4TT* +0.0 881 1.000000045 LA6TPA +0.5 213 1.000000515 LZ2ZG +2.2 224 1.000002232 LZ3CB* +0.5 867 1.000000464 LZ3ZZ +14.3 426 1.000014293 LZ4AE +0.4 1400 1.000000391 LZ4UX +0.3 981 1.000000258 LZ7AA +0.3 923 1.000000301 M5ADL +3.1 250 1.000003050 N0OI +1.2 252 1.000001206 N4ZR/3* +0.1 678 1.000000120 N5RZ +0.5 1813 1.000000511 N6TV* +0.1 519 1.000000141 N6WIN-7 -2.7 1547 0.999997292 N7TUG* -0.4 69 0.999999587 NA0B +1.7 17 1.000001672 NC7J* +0.2 889 1.000000226 NN3RP* -0.1 422 0.999999943 NU6XB -3.5 463 0.999996526 NX5M +0.6 662 1.000000602 OE9GHV +0.3 2222 1.000000342 OH4KA +4.4 793 1.000004434 OH6BG +0.8 1168 1.000000781 OH8X +1.1 1319 1.000001100 OK2EW -0.3 1721 0.999999684 OL7M* -0.2 2075 0.999999828 OM8AW -1.4 1172 0.999998565 ON6ZQ +1.5 1301 1.000001533 PA0MBO +0.0 9 1.000000000 PA3AIN -19.8 6 0.999980230 PJ2A -1.5 891 0.999998488 PY1CG* +0.6 140 1.000000560 R1LB +0.9 236 1.000000905 R6YY +1.5 449 1.000001466 RL3A-2 +1.1 697 1.000001063 RN4WA* +0.1 486 1.000000143 RU9CZD +1.7 503 1.000001701 S50ARX +1.1 473 1.000001101 S50U +1.6 359 1.000001573 SE5E -0.6 1684 0.999999388 SJ2W +1.0 1706 1.000001048 SM0TCZ +0.6 128 1.000000612 SM6FMB* +0.5 444 1.000000519 SM7IUN -1.7 1431 0.999998301 SP5SR +0.0 33 1.000000000 SP6FCS +0.3 115 1.000000344 SV8RV +3.3 647 1.000003296 TF3Y* -0.4 799 0.999999624 TF4X -1.9 2075 0.999998064 UA4M +3.8 1298 1.000003760 UY2RA +0.5 299 1.000000488 V51YJ +0.6 72 1.000000610 VE2WU +0.6 406 1.000000650 VE3NZ +1.5 890 1.000001451 VE6AO -3.0 335 0.999996994 VE6WZ +1.5 1041 1.000001517 VE7CC* +0.3 780 1.000000296 VK3RASA -10.4 68 0.999989559 VK4CT -0.3 338 0.999999662 VK6ANC -1.1 132 0.999998941 W1NT-2 -0.7 1775 0.999999266 W1NT-6 -0.6 2463 0.999999356 W2AXR +1.7 1904 1.000001739 W2NAF +0.9 1968 1.000000904 W3LPL +0.9 2138 1.000000851 W3OA* +0.1 1168 1.000000081 W3OA-2* -0.1 188 0.999999865 W3RGA* +0.1 1426 1.000000108 W3UA +1.6 1879 1.000001604 W4AX +3.6 374 1.000003617 W6BB -3.4 220 0.999996624 W7HR +0.6 234 1.000000640 W8WWV +0.6 1464 1.000000574 W9XG +4.0 695 1.000003973 WA3OPY +11.7 39 1.000011675 WA7LNW -1.9 1491 0.999998140 WA9VEE +0.0 8 1.000000000 WB6BEE* +0.0 1252 1.000000034 WC2L +0.2 756 1.000000245 WE9V* -0.3 1574 0.999999714 WH7W -0.4 345 0.999999625 WS3W -22.2 1103 0.999977759 WZ7I +0.0 2457 1.000000012 ZL2BR +1.3 38 1.000001314 ZL4YL +1.6 168 1.000001613 ZS6BNE +1.5 29 1.000001476 Last updated 2021-01-27 00:10:13 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 21-01-26 21-01-25 21-01-24 21-01-23 21-01-22 ------------------------------------------------------------- 3B8CW +0.4 +0.4 +0.4 +0.3 -0.1 3D2AG +0.1 +0.5 -4.5 -0.2 -1.2 3V/KF5EYY +0.3 +0.4 +0.1 +0.1 -0.1 5W1SA +0.0 +0.0 +0.6 +0.5 7N4XCV +1.3 +0.4 9A1CIG +3.9 +3.5 +3.2 +3.3 +3.0 9V1RM -1.3 -1.6 -1.4 -1.8 -1.3 AC0C-1 -0.0 +0.0 -0.1 -0.1 +0.1 BD7JNA -3.4 +0.4 -2.4 BD7LLL +1.5 +0.1 +0.6 +0.3 BD7LMD -4.8 -5.8 -4.2 -4.5 -4.1 BD7MLA +1.2 +0.9 +1.1 +1.4 +1.4 BG4GOV -7.1 BH1VCS +0.0 BH4RRG-1 +1.6 +5.3 +5.5 +4.8 BU2EQ +1.3 +0.0 +1.0 BY1CY +1.2 CE6MOA -20.2 -17.6 -21.2 -16.5 -18.2 CX6VM +0.1 +0.1 -0.3 -0.1 -0.1 DD0VS +0.3 -0.9 DD5XX +0.5 +0.6 +0.2 +0.2 +0.2 DD5XX-3 +0.0 DE1LON -1.6 -1.1 -2.1 -1.3 -1.9 DF2CK +13.1 DF4XX +0.4 -0.0 -0.4 -0.7 -0.4 DF7GB +0.4 +0.3 +0.0 -0.1 +0.0 DJ2BC -0.2 -0.1 -1.1 DK0TE +1.5 +1.7 +1.9 +1.9 +1.4 DK3UA +0.5 +0.3 -0.1 -0.1 -0.2 DK3WW +0.3 +0.8 -6.3 DK9IP +0.3 +0.4 -0.1 +0.0 +0.0 DL0PF +1.7 +1.6 +0.9 +1.6 +1.0 DL3DTH +0.7 +0.7 +0.4 +0.4 +0.3 DL8LAS -2.9 -2.7 -4.9 +0.6 -2.0 DL8TG -0.5 -0.5 -1.1 -1.0 -1.0 DL9GTB +0.9 +1.1 +1.3 +1.5 +0.8 DM6EE -4.2 -3.6 +0.7 +1.7 +0.8 DM7EE -3.9 -2.7 +0.4 +0.3 +0.2 DO4DXA +0.1 -0.1 -0.4 -0.3 -0.0 DR4W -0.1 +0.1 -0.2 +0.4 +0.4 E28AC +1.5 +1.9 +2.9 +2.4 +1.0 EA1URA +0.2 +0.1 -0.0 -0.1 -0.1 EA5WU +0.1 +0.0 -0.2 -0.4 +0.0 EA8/DF4UE +0.2 +0.1 -0.0 -0.1 -0.0 ES3V -0.8 -1.0 -1.5 -1.6 -1.7 ET3AA +0.2 +0.2 +0.6 +0.0 +0.3 F4VSQ +5.9 +5.2 +4.9 F6IIT -0.2 -0.8 -1.4 -1.1 -0.7 G0KTN +0.5 +0.5 G0LUJ -0.8 -0.8 -1.7 -1.6 -0.8 G0TMX -0.3 +0.2 G4AON +1.6 +1.4 +0.9 G4HSO +0.3 -0.2 -0.6 +0.1 -0.0 G4SGX +0.9 G4ZFE +0.4 +0.4 -0.2 +0.1 -0.0 GI4DOH +0.9 +1.0 +0.9 +0.9 +0.6 GM6DX -0.3 -0.4 +0.3 +0.5 +0.2 HA1VHF -1.0 -0.9 -1.5 -1.4 -1.4 HA5PP +1.5 HA6PX -2.2 -1.6 -1.6 -1.5 -1.9 HA7GN -0.6 -0.3 -0.9 -0.9 -1.0 HA8TKS +0.5 +0.3 +0.7 +0.7 HB9BXE +0.9 +0.9 +0.7 +0.8 +0.4 HB9DCO -24.3 -23.7 -2.3 +0.3 -0.5 HB9JCB +1.6 +1.6 +1.7 +1.6 +1.1 HS8KVH +2.8 +3.8 +4.4 +3.6 +2.7 IK3STG -1.3 -1.3 -2.3 -2.1 -2.1 IK4VET-1 +0.0 -0.3 -0.4 IZ2CPS -0.9 -1.0 -1.6 -1.4 -1.4 JA4ZRK +0.0 +0.7 +0.3 +0.4 +0.0 JE1SGH +3.0 JG1DLY -1.0 JH7CSU1 +2.6 +2.4 +3.7 +3.1 +2.7 JI1HFJ +0.7 +0.5 JJ2VLY -3.7 -2.3 -2.5 -4.4 -2.9 JQ1BVI +0.3 -0.2 -0.2 +0.3 -0.1 JR1BFZ/2 +0.3 -0.7 -0.2 -0.1 -0.8 K1FC -1.4 -1.4 +0.0 -2.0 K1TTT -0.0 -0.2 -0.1 -0.1 -0.2 K2DB +0.8 +0.1 -1.0 +0.2 -1.3 K2PO/7 +0.6 +0.7 +0.8 +0.8 +0.2 K3LR +0.2 -0.2 +0.7 +0.2 +0.3 K7EG +0.7 +0.7 +0.6 +1.0 +0.3 K7MJG -1.5 -1.3 -0.1 -6.8 -10.2 K9IMM +0.1 +0.0 +0.2 +0.0 +0.0 K9LC +0.2 +0.1 +0.1 -0.0 -0.0 K9TM-4 +0.7 +0.6 +0.8 +0.9 +0.5 KC0VKN -0.9 -1.0 -1.5 -2.1 -1.0 KC4YVA +3.8 +4.2 +4.1 +4.8 +3.8 KD2OGR +0.1 +0.0 +0.1 -0.0 +0.2 KD7YZ +0.1 +0.1 +0.1 +0.1 +0.1 KI4PAD -2.3 -2.8 -3.6 -4.1 -3.0 KM3T +0.1 +0.2 +0.1 -0.0 +0.1 KM3T-1 +0.3 +0.1 +0.3 +0.1 +0.0 KM3T-2 +0.1 +0.0 -0.2 -0.0 +0.0 KM4SII +0.1 KO7SS -2.8 -1.2 +0.1 +0.5 -0.0 KO7SS-7 -0.0 +0.0 +0.0 -0.2 -0.0 KP2RUM -0.1 -0.1 -0.3 -0.2 -0.1 KQ8M +0.4 -0.0 +0.3 +1.1 KU7T -0.3 -0.5 -0.4 -0.6 -0.2 KV4TT +0.0 +0.2 +0.2 +0.2 +0.2 LA6TPA +0.5 +0.3 +0.2 +0.1 +0.8 LY2XW +0.4 +0.7 LZ2ZG +2.2 +3.1 +3.8 +4.3 +2.4 LZ3CB +0.5 +0.3 +0.1 -0.0 +0.1 LZ3ZZ +14.3 +11.7 +6.8 LZ4AE +0.4 +0.6 +1.3 +1.3 +0.7 LZ4UX +0.3 +0.1 +0.1 +0.2 -0.1 LZ5DB-2 +1.0 +0.3 LZ7AA +0.3 +0.3 +0.0 M5ADL +3.1 +1.9 +2.5 +0.0 -0.2 N0OI +1.2 +4.6 +3.6 +5.2 +4.1 N4ZR/3 +0.1 -0.1 -0.4 -0.2 -0.0 N5RZ +0.5 -0.6 -1.8 -2.3 -1.9 N6TV +0.1 +0.1 +0.0 -0.1 -0.0 N6WIN-7 -2.7 -2.2 -1.9 -2.0 -1.2 N7TUG -0.4 -0.2 -0.1 -0.7 -0.3 NA0B +1.7 +0.6 +0.3 -0.3 +0.0 NC7J +0.2 +0.3 +0.4 +0.4 +0.3 NH6V +0.0 -0.3 NN3RP -0.1 +0.0 -0.2 -0.0 -0.2 NU6XB -3.5 -3.2 -3.6 -3.4 -2.8 NX5M +0.6 +0.9 +0.5 +0.5 +0.2 OE6ADD +0.2 -0.2 +0.1 OE9GHV +0.3 +0.3 -0.0 -0.0 +0.1 OH2BBT +13.1 OH4KA +4.4 +4.3 +4.8 +4.5 +2.8 OH6BG +0.8 +0.7 +0.6 +0.7 +0.5 OH8X +1.1 +1.2 +1.0 +0.9 +0.6 OK2EW -0.3 -0.2 -1.1 -0.8 -0.8 OL7M -0.2 +0.0 -0.3 -0.2 -0.3 OM8AW -1.4 -1.2 -1.4 -1.1 -1.5 ON6ZQ +1.5 +1.2 +0.5 +1.0 +0.7 PA0MBO +0.0 +0.5 +0.3 +0.1 +0.1 PA3AIN -19.8 +34.9 +14.2 -36.6 PA5KT -1.9 -1.1 PJ2A -1.5 -1.4 -2.2 -2.1 -1.5 PR1T -1.2 -1.5 -1.2 PS8CW +13.4 +11.8 PY1CG +0.6 +0.1 R1LB +0.9 +1.4 +2.0 +1.8 +1.0 R6YY +1.5 +1.7 +1.2 +1.2 +0.6 RL3A-2 +1.1 +1.3 +1.2 +1.1 +0.4 RN4WA +0.1 -0.0 -0.4 -0.4 -0.4 RU9CZD +1.7 +1.5 +2.5 +2.2 +1.8 S50ARX +1.1 +1.2 +1.4 +1.2 +0.6 S50U +1.6 +1.3 +2.0 +1.6 +1.3 S53M -7.9 SE5E -0.6 -0.4 -1.0 -0.9 -0.7 SJ2W +1.0 +0.8 +0.7 +0.7 +0.7 SM0TCZ +0.6 +0.6 +1.6 +1.8 +1.2 SM6FMB +0.5 +0.1 -0.2 -0.1 -0.2 SM7IUN -1.7 -1.4 +0.1 +0.1 +0.1 SP5SR +0.0 -1.5 +1.1 +0.5 +0.6 SP6FCS +0.3 SV1CDN -0.3 SV8RV +3.3 +3.0 +3.1 +2.8 +2.5 SZ1A -6.1 -5.9 -5.5 TF3Y -0.4 -0.6 -0.9 -0.8 -0.8 TF4X -1.9 -2.3 -2.4 -2.4 -2.0 UA4M +3.8 +4.1 +3.9 +3.8 +1.8 UY2RA +0.5 -0.2 V51YJ +0.6 +1.2 +1.0 +1.5 VE2WU +0.6 -0.7 -1.0 -0.1 +0.6 VE3NZ +1.5 +1.5 +0.9 +1.3 +1.6 VE6AO -3.0 -3.1 -2.0 -2.8 -2.8 VE6WZ +1.5 +1.3 +1.4 +1.7 +1.1 VE7CC +0.3 +0.2 +0.3 +0.1 +0.0 VK2GEL -7.4 +2.5 +3.6 VK3RASA -10.4 -8.7 -7.2 VK4CT -0.3 -0.6 -0.3 -1.0 -0.7 VK6ANC -1.1 -0.4 -0.6 -0.9 -0.3 VU3KAZ -0.6 -0.5 VY0ERC -2.5 W1NT-2 -0.7 -1.0 -1.0 -1.2 -0.9 W1NT-6 -0.6 -0.8 -1.0 -0.9 -0.9 W2AXR +1.7 +1.8 +1.6 +1.7 +1.2 W2LB +1.2 +0.8 -0.6 W2NAF +0.9 +0.7 +0.7 +0.8 +0.6 W3LPL +0.9 +1.0 +0.9 +1.0 +0.6 W3OA +0.1 -0.1 -0.2 -0.2 -0.1 W3OA-2 -0.1 -0.1 -0.3 -0.0 -0.0 W3RGA +0.1 +0.2 +0.0 +0.2 -0.0 W3UA +1.6 +1.6 +1.8 +1.9 +1.6 W4AX +3.6 +3.8 +4.0 +3.6 +3.1 W6BB -3.4 -3.1 -2.9 -3.9 -2.0 W7HR +0.6 +1.0 +0.8 +1.3 +0.5 W8WTS -0.6 -1.0 W8WWV +0.6 +0.5 +0.6 +0.5 +0.4 W9XG +4.0 +4.0 +3.3 +3.4 +3.6 WA3OPY +11.7 +11.5 +11.8 +9.9 +12.9 WA7LNW -1.9 -1.5 -1.6 -1.4 -0.9 WA9VEE +0.0 +0.0 WB6BEE +0.0 +0.2 -0.0 -0.0 +0.1 WC2L +0.2 +0.0 -0.2 -0.3 -0.2 WE9V -0.3 -0.5 +0.4 +0.1 -0.1 WH7W -0.4 -0.7 +19.5 +24.4 +23.9 WS3W -22.2 -15.3 +11.5 +3.5 -2.0 WZ7I +0.0 +0.1 -0.1 -0.1 -0.1 YO4SVZ -12.5 ZL2BR +1.3 +1.1 +0.6 +0.9 +0.3 ZL4YL +1.6 +1.3 +0.9 +1.7 +0.7 ZS6BNE +1.5 +1.8 +1.8 +1.6 +1.8 Last updated 2021-01-27 00:10:18 UTC
Activity statistics
Summary of unique calls spotted and active skimmers per band and continent.
RBN activity between 2021-01-26 00:00 and 23:59 UTC.
314117 spots with 8036 unique callsigns from 189 active skimmers.
Unique callsigns spotted per continent and band
---------------------------------------------------------------
160m 80m 60m 40m 30m 20m 17m 15m 12m 10m 6m
AF 3 20 3 38 7 38 9 12 3 2 1 104
AS 55 150 2 337 36 159 49 42 8 3 4 664
EU 373 1137 155 1663 500 1501 332 235 33 82 8 4310
NA 156 538 39 1323 304 780 242 183 52 101 7 2685
OC 3 16 1 68 15 40 12 21 2 2 0 130
SA 1 2 0 87 5 43 11 14 5 12 0 143
591 1863 200 3516 867 2561 655 507 103 202 20
Active skimmers per continent and band
---------------------------------------------------------------
160m 80m 60m 40m 30m 20m 17m 15m 12m 10m 6m
AF 3 4 1 5 5 5 5 5 2 3 0 6
AS 10 13 0 16 10 17 8 15 3 2 1 17
EU 69 75 23 78 66 67 46 54 11 31 4 85
NA 50 54 17 60 42 58 35 48 24 39 2 67
OC 2 7 1 8 7 9 6 8 2 2 1 10
SA 2 1 0 3 2 4 3 4 1 2 0 4
136 154 42 170 132 160 103 134 43 79 8
Last updated 2021-01-27 00:10:45 UTC