A crystal sphere of YIG was placed in either a doubly resonant transmission type coaxial cavity or intoa nonresonant transmission line device and biased with a dc magnetic field. A low power microwave signalin the S band frequency range (cw or pulsed) was used to excite resonance. Current pulses of approximately1 &mgr;sec duration and low duty cycle were sent through a low impedance coil that was wound around thecavity or transmission line respectively. These pulses induced pulsed magnetic fields of the order of 1000gauss, which (vectorially) added to the existing dc field.A microwave receiver, attached to the cavity output, detected weak oscillations at higher or lowerfrequencies. Shifts of 280 Mc have been obtained with the cavity, and shifts of 1280 Mc above and 530 Mcbelow the driving frequency have been obtained with the transmission type device.The detected signal is associated with either the rise of the current pulse, or the decay, or two signals mayappear simultaneously corresponding respectively to the rise and decay. This depends upon the angularrelation of the dc field with respect to the cavity or transmission line.