A pulsed spectrometer designed for feedback NQR

A pulsed NQR spectrometer specifically designed to facilitate real-time tun ing of pulse sequence parameters is described. A modular approach based on the interconnection of several rack-mounted blocks provides easy access to all spectrometer signals and simplifies the task of modifying the spectrome ter design. We also present experimental data that demonstrates the ability of the spectrometer to increase the signal to noise ratio of NQR measureme nts by automatically adjusting the pulse width in the strong off-resonant c omb pulse sequence.