  We investigate the minimal conditions to store coherently a RF pulse in a
material medium. We choose a commercial quartz as memory support because it is
a widely available component with a high Q-factor. Pulse storage is obtained by
varying dynamically the light-matter coupling with an analog switch. This
parametric driving of the quartz dynamics can be alternatively interpreted as a
stopped light experiment. We obtain an efficiency of 26%, a storage time of
209$\mu$s and a time-to-bandwidth product of 98 by optimizing the pulse
temporal shape. The coherent character of the storage is demonstrated. Our goal
is to connect different types of memories in the RF and optical domain for
quantum information processing. Our motivation is essentially fundamental.
