We report electric field induced phase displacements of the charge density wave (CDW) in a single crystal of NbSe3 using Nb93 NMR spin-echo spectroscopy. CDW polarizations in the pinned state induced by unipolar and bipolar pulses are linear and reversible up to at least E=(0.96)ET. The polarizations have a broad distribution extending up to phase angles of order 60° for electric fields close to threshold. No evidence for polarizations in excess of a CDW wavelength or for a divergence in polarization near ET are observed. The results are consistent with elastic depinning models, provided that the critical regime expected in large systems is not observable. © 2008 The American Physical Society.