11610kHz - Possible Jammer (also 13570, 15400, 17735kHz)

Haven't seen such thing before. Also seen at: 13570kHz, 15400kHz, 17735kHz. These signals are affected by the propagation.
QTH: Kraków / Cracow - Poland, Receiver: Airspy HF+ Dual Port, Antenna: 30m band dipole