Indeed - 

What happened to WOLF  (*) ?

I've just tried Googling (**) it and find practically no hits.  The data mode seems to have been used successfully  in the years around 2001 and on, for a bit, but has faded.   The URL I had for it is now gives the magic 404.  Didn't the first transatlantic contact on 137kHz use this mode?

I guess that as it used 10 baud  BPSK,  was considered too complicated for the average LF Op. to generate.   No one seems to use upconversion from audio, and few seem to be able to make simple PSK encoders.   Even for EBnaut, relays  are suggested as the means to reverse the phase (yes, truely !!).    I suppose, to be fair, 10 baud unfiltered BPSK from a high power transmitter is a bit unkind to other band users.

Andy  G4JNT

(*) Weak signal Operation at LF

(**) Other search engines are available - so it has been said.

On 4 January 2016 at 19:14, John Andrews <[email protected]> wrote:

For those who may be newer to this part of our hobby, Hartmut Wolff is somewhat of a legend in receiving TA signals in the 137 kHz band. Night after night while others could only see Loran lines and the debris from DCF39, Hartmut produced screenshots of some pretty weak North American signals. He also gave reports on the sadly-orphaned WOLF mode. As recently as last month, his 137.780 kHz grabber showed my signal on nights that it was invisible on the UK and other DL grabbers.