[600MRG] lost in the modulation maze.

[J Mcvey]

Hello all,
I have been trying to get things together in he shack for doing more with MF emissions.  Been tinkering with Fldigi, Spectrum Labs and WSJT. So far I have not found any intelligible modulation other than CW on MF. There are several "mysterious" very narrow carriers but none of the afore mentioned interfaces can make any sense of them. Are these just carriers or is there some other modulation type being used?Also what is the audio/visual  signatures of WSPR, FSK441, and QSK31?  Are they distinct like PSK31? 

So far this has been an exercise in frustration after two hours of trying different modulation decoders on various signals without any result other than gibberish.I get "hits" in FSK441 mode according to WSJT where it makes a file name width info, etc, but the rest of it is noise-no ID, no message. I;m not sure why that happens. Is it just the software false triggering or is it a real weak signal?
I've been keeping the search between 468KHZ and 500KHZ. Am I looking in the wrong place?
Thanks in advance the info.
Jim