I just started transmitting with my Ultimate 3 yesterday afternoon. Therefore forgive me my question, it is just to clarify something.
I was transmitting on exactly 7040.120 kHz with high accuracy. But the reports that I later received on WPRSnet all differed in indicated frequency by up to 40 Hz. See an example:
2015-10-09 22:54 DL2QB 7.040137 -26 0 JO30hj 1 F4ARU
2015-10-09 22:48 DL2QB 7.040137 -23 0 JO30hj 1 F4ARU
2015-10-09 22:42 DL2QB 7.040137 -17 0 JO30hj 1 F4ARU
2015-10-09 22:24 DL2QB 7.040137 -24 0 JO30hj 1 F4ARU
2015-10-09 21:48 DL2QB 7.040123 -25 0 JO30hj 1 LZ1UBO
2015-10-09 21:06 DL2QB 7.040123 -22 0 JO30hj 1 LZ1UBO
2015-10-09 21:00 DL2QB 7.040123 -18 0 JO30hj 1 LZ1UBO
2015-10-09 20:54 DL2QB 7.040123 -20 0 JO30hj 1 LZ1UBO
2015-10-09 20:48 DL2QB 7.040120 -25 0 JO30hj 1 VK7AB QE37ne
2015-10-09 20:30 DL2QB 7.040123 -26 0 JO30hj 1 HS0ZKM
2015-10-09 20:30 DL2QB 7.040119 -21 0 JO30hj 1 VK7AB QE37ne
2015-10-09 20:30 DL2QB 7.040125 -22 0 JO30hj 1 VK5MR PF96lh
2015-10-09 20:24 DL2QB 7.040124 -8 0 JO30hj 1 LZ1UBO
2015-10-09 20:18 DL2QB 7.040124 -1 0 JO30hj 1 LZ1UBO
2015-10-09 20:18 DL2QB 7.040126 -23 0 JO30hj 1 EA1CDV
2015-10-09 20:18 DL2QB 7.040125 -23 0 JO30hj 1 VK5MR PF96lh
2015-10-09 20:12 DL2QB 7.040125 -26 0 JO30hj 1 VK5MR PF96lh
2015-10-09 19:18 DL2QB 7.040135 -22 0 JO30hj 1 PA2W JO22lf
2015-10-09 19:06 DL2QB 7.040123 -25 1 JO30hj 1 HS0ZKM
2015-10-09 19:06 DL2QB 7.040124 -7 0 JO30hj 1 LZ1UBO
2015-10-09 19:00 DL2QB 7.040120 -14 0 JO30hj 1 F1JRD JN03ql
2015-10-09 19:00 DL2QB 7.040137 -11 0 JO30hj 1 F4ARU JN03ql
2015-10-09 19:00 DL2QB 7.040124 -5 1 JO30hj 1 LZ1UBO
2015-10-09 19:00 DL2QB 7.040126 -27 0 JO30hj 1 EA1CDV
2015-10-09 19:00 DL2QB 7.040123 -27 0 JO30hj 1 HS0ZKM
2015-10-09 18:54 DL2QB 7.040120 -16 0 JO30hj 1 F1JRD JN03ql
2015-10-09 18:48 DL2QB 7.040124 -28 0 JO30hj 1 VK5MR PF96lh 3
2015-10-09 18:42 DL2QB 7.040123 -15 0 JO30hj 1 LZ1UBO
2015-10-09 18:42 DL2QB 7.040120 -10 0 JO30hj 1 F1JRD JN03ql
2015-10-09 18:42 DL2QB 7.040137 -6 0 JO30hj 1 F4ARU JN03ql
2015-10-09 18:36 DL2QB 7.040124 -5 0 JO30hj 1 LZ1UBO
2015-10-09 18:36 DL2QB 7.040120 -7 0 JO30hj 1 F1JRD JN03ql
2015-10-09 18:36 DL2QB 7.040137 -2 0 JO30hj 1 F4ARU JN03ql
2015-10-09 18:30 DL2QB 7.040137 -1 0 JO30hj 1 F4ARU JN03ql
2015-10-09 18:30 DL2QB 7.040120 -1 0 JO30hj 1 F1JRD JN03ql
2015-10-09 18:24 DL2QB 7.040134 -22 0 JO30hj 1 LA9JO JP99gb
2015-10-09 18:24 DL2QB 7.040041 -10 0 JO30hj 1 LA1NRA
2015-10-09 18:24 DL2QB 7.040131 -6 0 JO30hj 1 SP7GJ JO91
2015-10-09 18:18 DL2QB 7.040123 -11 0 JO30hj 1 SM0VYI
2015-10-09 18:18 DL2QB 7.040041 -8 0 JO30hj 1 LA1NRA
2015-10-09 18:18 DL2QB 7.040119 -23 0 JO30hj 1 F1JRD JN03ql
2015-10-09 18:18 DL2QB 7.040121 -29 0 JO30hj 1 4X1RF KM72ls
2015-10-09 18:18 DL2QB 7.040133 -20 0 JO30hj 1 LA9JO JP99gb
2015-10-09 18:18 DL2QB 7.040136 -17 0 JO30hj 1 F4ARU JN03ql
2015-10-09 18:12 DL2QB 7.040121 -27 0 JO30hj 1 4X1RF KM72ls
2015-10-09 18:12 DL2QB 7.040131 -7 0 JO30hj 1 SP7GJ JO91 872 77
2015-10-09 18:12 DL2QB 7.040123 -8 0 JO30hj 1 SM0VYI
2015-10-09 18:12 DL2QB 7.040123 -2 0 JO30hj 1 LZ1UBO
2015-10-09 18:12 DL2QB 7.040041 -10 0 JO30hj 1 LA1NRA
2015-10-09 18:06 DL2QB 7.040123 -19 0 JO30hj 1 SM0VYI
2015-10-09 18:06 DL2QB 7.040137 -19 0 JO30hj 1 F4ARU JN03ql
2015-10-09 18:06 DL2QB 7.040123 -6 0 JO30hj 1 LZ1UBO
2015-10-09 18:06 DL2QB 7.040123 -21 0 JO30hj 1 OH6GAP
2015-10-09 18:06 DL2QB 7.040042 -13 0 JO30hj 1 LA1NRA
2015-10-09 18:06 DL2QB 7.040121 -27 1 JO30hj 1 4X1RF KM72ls
2015-10-09 18:06 DL2QB 7.040134 -22 0 JO30hj 1 LA9JO JP99gb
2015-10-09 18:00 DL2QB 7.040133 -21 0 JO30hj 1 LA9JO JP99gb
2015-10-09 18:00 DL2QB 7.040136 -18 0 JO30hj 1 F4ARU JN03ql
Does this happen because a lot of the receivers are not tuned down to the last Hz to the proper receiving frequency so that the WSPR receiving software calcultaes slightly wrong receiving frequncies based on the pitch of the received tone frequncies assuming that the virtual carrier frequncy is exactly 1500Hz lower?