  Kerr microresonators driven in the normal dispersion regime typically require
the presence of localized dispersion perturbations, such as those induced by
avoided mode crossings, to initiate the formation of optical frequency combs.
In this work, we experimentally demonstrate that this requirement can be lifted
by driving the resonator with a pulsed pump source. We also show that
controlling the desynchronization between the pump repetition rate and the
cavity free-spectral range (FSR) provides a simple mechanism to tune the center
frequency of the output comb. Using a fiber mini-resonator with a radius of
only 6 cm we experimentally present spectrally flat combs with a bandwidth of 3
THz whose center frequency can be tuned by more than 2 THz. By driving the
cavity at harmonics of its 0.54 GHz FSR, we are able to generate combs with
line spacings selectable between 0.54 and 10.8 GHz. The ability to tune both
the center frequency and frequency spacing of the output comb highlights the
flexibility of this platform. Additionally, we demonstrate that under
conditions of large pump-cavity desynchronization, the same cavity also
supports a new form of Raman-assisted anomalous dispersion cavity soliton.
