Wide Line NMR Induction and Bridge Spectrometer for the Frequency Range 2–90 MHz

Abstract

A wide band, variable frequency nuclear magnetic resonance spectrometer is described for use with either a crossed-coil induction probe in the frequency range 2 to 40 MHz or a parallel T rf bridge from 2 to 90 MHz. A novel use of simple rf circuits is described wherein the receiver amplifier has useful gain to 95 MHz and the transmitter amplifier has useful gain to 45 MHz. A simple modification of the Varian Associates 8 to 16 MHz induction probe for use with this circuit to 40 MHz is described. Sensitivity of the instrument with both the probe and bridge compares most favorably with a commercial induction spectrometer. The circuit is essentially free of microphonic noise.