A variable frequency generator regulation control circuit and method for controlling open loop gain under changing generator speed conditions employing a high frequency pulse-width modulated signal with a duty cycle that is controlled such that variations in rectified PMG voltage and generator gain over the generator speed range can be compensated for. This signal is modulated by a low frequency pulse-width modulated signal provided by the generator regulator, using a logic gate to produce a combined signal representing an average voltage signal applied to a generator field winding as the generator speed fluctuates.