A nuclear quadrupole resonance spectrometer with automatic gain control and sideband suppression

Abstract

A cw nuclear quadrupole resonance spectrometer centered on the superregenerative oscillator and working in the range 20–40 MHz is described. Both automatic gain control and sideband suppression have been incorporated by using external quench waveforms of variable mark-to-space ratio. Extensive use of ICs in these circuits leads to ease of construction as well as increased reliability. The S/N obtained remains unaffected by the automatic gain control while the sideband suppression does give rise to a small degradation. The spectrum of NaClO3 has been recorded.