In the heyday for lowfers over a dozen signals could be copied around the 185.3 kHz watering hole. Today I only know of WM, TAG, and SIW currently active. WD2XVN, a higher powered experimental licensed CW station, in CA is active on 183.5 kHz. A few others may start up now that it's winter. WSPR seems to be the preferred mode for hifers, even though wsjt-x mode fst4w is slightly more sensitive. At lowfer frequencies 2 min WSPR won't be copied very far so at times SIW sends the 15 min version. I've had no software problems with wspr version 0.8, the only version that offers that mode, but others have. SIW also sends opera32 for even better sensitivity. Likewise the software for that mode isn't well thought of.
Today the 1800 sec version of fst4w (or fst4 for 2-way qsos) would be a better choice. Receiving it is easy but transmitting it may be a challenge. For example, the popular QRP labs Ultimate3S kits do not include wsjt-x modes. I've generated the signal at hifer frequency by mixing the output of an 80 mtr TX with a GPS-locked 10 Mhz OCXO. For lowfer frequencies one could instead use a 30 mtrs TX.
Some years ago SIW experimented with what is called slash code in an attempt to make DX reception easier. TAG used to send Wolf mode transmissions for even better sensitivity. And for the ultimate in sensitivity SIW transmitted a short message using EbNaut modulation in 2019. None of that generated much interest.
There is plenty of information on the web about how to make efficient lowfer PAs, how to wind variometers to match to the antenna, and how to build vertical and loop antennas. The only thing lacking these days of instant worldwide cell phone communications seems to be individuals interested in doing something themselves.
73, Garry K3SIW, EN52tb