Thanks to all who answered. From all the answers I got, the problem may be
due to the probe, the SGU's, the 1H preamp or the 1H amp. I checked the SGU's
and that was not the problem. To check the other parts, I will need an
oscilloscope and a proper attenuator. I have an oscilloscope for our 400 MHz
Avance III NMR spectrometer but not a proper attenuator (30 dB dummy load).
So, I will wait for the Bruker engineer to come here to install our new
500 MHz Avance Neo solid-state NMR spectrometer (in about a month time),
ask him to check and replace the faulty part. In the meantime and according
to the answers I got, it is likely that the 1H amplifier is not amplifying
anymore.
Thanks again for your answers.
Pierre Kempgens.
Received on Tue Feb 28 2023 - 03:49:45 MST