Wide‐band solids, rapid recovery, multinuclear transceiver/digitizer for a high‐resolution NMR spectrometer

A transceiver which is capable of observation of spectral widths of 1.6 MHz has been constructed as an accessory to a Bruker WH‐400 NMR spectrometer. This device permits observation of the NMR resonances of solid‐state quadrupolar nuclei, which may contain frequency components more than 1 MHz away from their fundamental precession frequencies. The transceiver contains its own frequency generation section, which employs the host spectrometer’s master phase reference and synthesizer. The NMR signal undergoes image rejection mixing to an intermediate frequency above the observation band, and quadrature phase detection before final amplification with video speed operational amplifiers in the receiver section. Dual 8‐bit, video speed digitizers feed the converted data to dual 16 kword deep buffers that can accept data at a rate of 4 Msamples/s. A slower data output rate is governed by the Bruker Aspect host computer. The noise figure of the device is 1.8 dB, with a sensitivity of at least −71 dBm and a recover...