Take a look here -
http://www.bunkerofdoom.com/lit/HAM_M_ROTORS.PDFThis manual is for a Ham M, which is the model prior to the Ham IV. Depending on what info you need, this may be close enough.
You might also contact Norm at Norm's Rotor Service for assistance,
http://www.rotorservice.com/contactinfo.htmGood luck,
Stephen
N5VTU