I'm not sure. I just heard it on the KPH SDR, on 4097.27 again, just above the noise. I tried the second harmonic, at 8194.54, and it was coming through a bit stronger. The fact that the second harmonic was a bit stronger does make one wonder whether it is the Marin Ditter.
Do we know for a fact that Madonna is/was a distinctly different beacon, or was there always the possibility that it was simply the Marin Ditter?