Mike, You can download the manual here :http://www.hy-gain.com/man/pdf/HAM-IV.pdf You can also order the part from MFJ/Hygain or one of the aftermarket resellers: C.A.T.S (formerly the Rotor-Doc) at: http://www.rotor-doc.com/ or Norm's Rotor Service at http://www.rotorservice.com/. 73 de Bill, K9RZ