Eureka!! I found the QRM-source!
…and beleive it or not, it was the computer making noise, while radiating in such a way that it affected the MFJ-1026 ability to phase my loops correctly! I suddenly got the idea that I should try to connect my ICF-2001D to the phasing unit, and remove the SDR-IQ, computer and USB-hubs and voilá! Noise gone! Why in H*ll didn´t I think of doing that before? Tunnel-sight??
Tomorrow I will try to re-arrange the SDR-IQ setup in such a way that the computer and accessories doesn´t affect the phasing unit.
Right now listening with the ICF-2001D connected and it’s a true pleasure!