A NUCLEAR-QUADRUPOLE RESONANCE SPECTROMETER WITH AUTOMATIC GAIN-CONTROL AND SIDE-BAND SUPPRESSION

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.