Intermittent 1H and 19F pulse errors (amplitude and phase glitch)
From NMR Wiki
Instrument
Varian INOVA 500
Problem Description
In arrayed 19F acquisitions any number of spectra would display reduced amplitude and phase error compared to the rest of the array. The problem could be reproduced in 1H arrays as well, but the error would be less frequent. No glitches were seen in 13C spectra suggesting that the observe path was OK. No errors were observed in 31P spectra, suggesting that the transmitter board was OK (the transmitter uses two separate SSB mixers for 0-160 and 160-750 MHz). We also saw occasional decoupling problems in 13C{1H} spectra.
Solution
A loaner HB preamp fixed the problems.
