When tuning RTTY signals, I use a.
     (method)        (example)   
[ ]  Scope           (MMTTY software type)
[ ]  Scope           (a real scope)   
[X]  FFT display     (a la MMTTY)
[ ]  LED bar graph   (PK-232)
[ ]  LED x-y display (HAL DXP-38)
[ ]  by Ear
[ ]  other           (specify)
[ ]  I never have to tune. I only CQ.
My primary decoder is:   MMTTY via WinWarbler
My secondary decoder is: KAM98 via WinWarbler