I guess that most of you don't know me, although I have been there =
watching your discussion for quite a long time. I must say that I have =
benefit much from your discussion. Let me introduce myself first. I am =
the director of Analytical Center, East China Normal University. We have =
a Bruker MSL-300 spectrometer equipped with more than 10 probes. We are =
now facing with a strange problem and want to have your help.
Some strong interfering signals always appear when we carry out =
experiments with different probes at different frequency(with or without =
sample in the probes). These signals, last for more than 500us, change =
their position with reference frequency and look like real NMR signals. =
We have cleaned the probes and magnet, but found no change. These =
signals disappear when we take the probes out of the magnet or switch =
off the RF power amplifier. We really have no idea about where these =
signals come from.
Thanks in advance for your suggestion =20
Chen Qun
Director of Analytical Center
East China Normal University
Shanghai 200062, China