This application describes an MRI probe/transmitter coil that is composed of concentric cylinders with resonant elements. The probe/transmitter can be tuned using a plurality of freely rotating resonant elements radially mounted between the two cylinders. This invention reduces the effects of subject characteristic variations on the coil resonant frequency in an MRI system. Further, this apparatus increases the sensitivity and efficiency in the magnetic resonance system by raising the Q factor of the probe coil/transmitter. Prototype apparatus effectively reduces the significant coil-subject coupling at high frequencies.