A method is proposed for eliminating baseline distortions due to spurious ringings in Fourier transform NMR spectra involving broad resonances. It is based on the pulse sequence (~r/2)-(Acquisition/Add)-m-~-(n/2) (Acquisition/Subtract). T is of the order of, or shorter than, the spectrometer recovery time. The sensitivity of the method is discussed.In Fourier transform NMR, the success in measuring relatively broad resonances, arising for instance from quadrupolar nuclei, at low sensitivity and low radiofrequency (e.g. I7O, which resonates at 12.2MHz for a field of 2.1 T) often rests on the ability to remove transitory signals which occur just after the excitation pulse and whose amplitude decreases in a similar manner to the nuclear free induction decay. These transitory signals have various origins: oscillation of the probe circuit; recovery, after the high power pulse of the preamplifier and/or receiver network,' the so-called acoustic ringings and eddy currents due to the response to the radiofrequency pulse of the probe or magnet materials.2 This leads, in the Fourier transform spectrum, to baseline distortions which, at the limit, totally mask the expected NMR lines. Different remedies have been proposed, which include electronic devices that clamp the probe circuit by Q switching3 or negative feedback of the ~reamplifier.~ On the other hand, at a given frequency, a proper choice of materials can reduce acoustic ringing.'~~ Nevertheless, the problem has not yet found a universal solution, and most spectrometers cannot be adapted to the above remedies which are, anyway, partial or specific to a peculiar situation. One is then forced to find a means of removing or attenuating the effects of these spurious oscillations, rather than suppressing them effectively.Two approaches have, so far, been proposed: (i) the insertion of a delay, D, between the excitation pulse and the beginning of data acquisition. This delay must be longer than the time required for the extinction of the ringings, and entails large first-order phase corrections in the Fourier transform spectrum. These invariably lead to rolling baselines. A method is available, however, for avoiding these large phase corrections when the spectrum involves only two signals.6 (ii) The detection of half of the echo resulting from the well