Abstract: The details of the design and construction of an injection and frequency locked super-regenerative oscillator (SRO) type NQR spectrometer working in the frequency range of 13MHz-40MHz are presented. The spectrometer is composed of external quench super-regenerative-oscillator, a continuous wave oscillator with stability of about 10^-5 and a frequency locked unit. The quench frequency can be continuously adjusted from 15KHz to 150KHz. The advantages of the spectrometer are as follows. (I) the pure absorption or pure dispersion line-shapes can be obtained separately (ii) its frequency stability is determined only by that of an independent oscillator which provides a frequency locking signal (iii) the resonant frequency can be measured directly by a frequency counter. (iv) easy adjustment. A series NQR spectra of ³⁵Cl were measured with the spectrometer, and the results are presented.

Key words: Nuclear Quadrupole Resonance Spectrometer, Nuclear Quadrupole Resonance Speclroscopy