Hello Markus,

many thanks for sharing details of your very interesting experiment. As you known,  i have used your PLL method in my LF-EbNaut setup to generate a quite steady  modulating audio tone. But in my case, the feedback is taken at the output of the sound card before the ring-modulator that acts the bpsk.
If i have understood, you have now overcome the initial problem of this PLL that tends to cancels the psk modulation. That's good. I will try it in my next VLF local transmissions.

Since two days, i'm running a (temporarily !) VLF receiver/grabber with a resolution of 63 uHz:

https://www.dropbox.com/s/fsjkfuhggozzv5w/grabber.jpg?dl=0

Unfortunatly no signals on "dreamer" band in these two days of activity (made by you and Uwe)  was picked up. I'm working to improve reception trying to relocate the mini-whip. Next step will be to test a Loop antenna. By the way, the chances to pick up a VLF "dreamer" signal from Central Europe are very less here in my station in JN80 that is "urban-located" and fairly far from you.

I want to try to record and decode my local EbNaut signals on VLF. I made some reception test using Wolf's beta version that includes EbNaut facilities. I have succesfully tested it on MF during some test transmissions of IW4DXW. But i want test also your recording method that uses the FFT export file function of Spectrum Lab.
Taking in consideration that i'm using 48000 sample/s can you suggest the correct parameters needed for SL and for the sr.txt file used for the inverse-FFT program ?

Maybe someone else is interested at this method.

Thanks in advance.

73 and good week-end to all group

Domenico / iz7slz