I bought a generic USB to RS232 cable from Amazon and plugged the DB9 directly into the radio. Once I had the COM port assigned by the USB driver, I was able to get it to work with all my programs that offered a CAT interface to the TS2000. If you need to extend the connection from the DB9 to the radio, make SURE that your extender cable has straight-through connections (i.e. Pin 1 to Pin 1, Pin 2 to Pin 2, etc.).