[RTTY] TS930 and FSK Help

[Mack Johnson, AK4I]

Can I use the Kenwood TS930 and MMTTY with the 930 wired for FSK?  I am a
bit confused since when I xmt using a dummy load, say on 14.090, a separate
receiver set for LSB and running a separate copy of MMTTY on a laptop will
not decode unless I change the receiver to receive USB.  Decode then occurs
at about 14.088. The 930 MMTTY software is setup according to info from
AA5AU RTTY site and using the simple transistor interface.  I am new to
using FSK and RTTY in general but want to use my old TS930 for RTTY only.
In FSK the 930 receives and decodes great and I can use my filters, etc.   I
am sure I am missing something real simple.  Any help is surely appreciated.
Mack AK4I