Time-Sharing Modulation at 200 kc Applied to Broad and Narrow Line NMR for Base-Line Stability

Abstract

The time‐sharing method of alternately pulsing an NMR transmitter and receiver has proven useful in reducing base‐line instability due to leakage signal. In this paper, methods are described for increasing the repetition rates to 200 kc and higher, which displace the sidebands well away from the carrier, giving undistorted broad line absorption signals, and high resolution spectra without side band overlap (e.g., ¹⁹F spectra). Some undesirable features associated with field and frequency modulation are thus avoided. The method is accomplished quite simply using two pulsers, fast diode switches, and a broad band power amplifier.