Matt,
I believe I have a Kenwood 290 serial port cable that I loaned out - loanee is checking and if it is the one I am thinking I should have it next Monday if you are still in need.
Matt,
Got the cable back and it is the serial cable for x80, x90, x140 radios so should do what you need. PM me and we can figure out how to get it to you.
Steve