Having had the 320 for quite a while - it's really not a SDR - it's more a computer controlled radio (the RF and AF sections are entirely a standard design - no A/D conversions here...). It is, however, a darn good radio for the money. Put a good antenna on it and you'll be amazed a what that radio can hear...even digital stuff, too...
There is a RX320 Yahoo group where you can learn much more about this recently-discontinued (yes, I read somewhere that they have finally retired it...) radio here...
https://groups.yahoo.com/neo/groups/RX320/info
Undoubtedly you'll find your answers there, if no one here answers...Mike