Jim, M0BMU said

Over the last week or so, VO1NA has mostly been about -10dB to -15dB below
the audible threshold. This gives good "O" copy at QRSS30, and would

mostly

be OK at QRSS3. But, at best, the signal has been about 7dB below the
audible threshold. The 5wpm signal is visible as a "smudge" on the
spectrogram, but so far has not been audible. So Hartmut's reception is
remarkable - the SNR at his QTH must have been 10dB better than they were
here, which shows the degree of variation that exists between different
locations.

I agree. The attached shows what Joe's signal is like here most of the time
when conditions are reasonable. This capture done last night at 0320z, Argo
on 20sec slow.
The noise before the signal is visible might have been a 5wpm transmission.

Regards,
Peter, G3LDO