If you can do some simple soldering is not a hard job. All you need is a mini DIN connector to the ACjr. 6' of 9 conductor cable and a 9 pin serial plug(DB9) Look on page 23 of the manual for the pin out info. Radio shack should have all the parts your cost for materials willbe around $12.00.
Or spend $18.00 and order it
http://www.petstore.com/ps_ViewItem...nt_Monitor_Equipment_Accessories-vendor-.html
Good luck