Finally, thanks to Stefan DK7FC, I’ve my first “human” signal on 8 kHz band.
Stefan was active for all the last week-end on the band to give me a chance to receive his signal, and pixel after pixel the signal apeared in this way:
A well marked peak exactly on 8270.005 Hz shows the integration of the signal after many hours of transmission.
The distance between Stefan and me is about 940 Km, not bat at all! Stefan helped me to fine “tune” Spectrum Lab software to optimize the system for the best performance. As antenna I’ve used my loop oriented towards Heidelberg.
I think that other works, for a better receiving, could be done.