I've been using Joe Taylor's weak signal modes for a while now, mostly WSPR, but recently my attention has been drawn to an interesting spin-off which calls itslelf "JT65-HF".
Clearly many people have been there before me, as there is quite a bit of activity in this mode, which seems to be able to produce quite remarkable and astonishing results.
Having downloaded the software, set it up (easy peasy) and left it running for some hours, the resulting decodes have never ceased to amaze me, given the modest aerial setup I have here.
I presume that much of this is due to the "FEC" (Forward Error Correction) associated with this mode of transmission. Stations such as mine with modest capability therefore stand a good chance of getting their messages through, or conversely can successfully receive weak transsmissions from elsewhere to a remarkably high degree.
I would recommend anyone at least to have a look at this mode, and at what it can do.