Your local Model Shop / Hobby Store will sell the correct cable for your tranny.

I use Real Flight myself a\s Tony suggested, but most people at the club I used to hang out at used CSM. I'm sure it used to be free, have a hunt around you may get lucky.

I have a copy of Real Flight G2 which is going on eBay soon, it coms with all the cables for a Futaba tranny like mine (rectangle connector FF9) Let me know if you are interested it it, but they have moved onto G3 now.

Cheers

Cris.