We have a QE-300 with a Tecmag pulse programmer that is not scheduled to be
replaced for another 2 1/2 years. (We have the money, but are waiting on the
space to be constructed.) The 1H-13C probe is a reconditioned probe just
bought in January.
Over the past couple months, we have had a problem with very predominant
spinning sidebands. Initial attempts at shimming them away didn't work, but
at one point, I was able to reduce the first order sidebands to below 2%.
This lasted two weeks and now we have very large first, second, third,
etc. -order sidebands. Adjusting the non-spinning shims currently only
reduces the sidebands to around 6-7%.
Any ideas what is causing these spinning sidebands to return? I was
wondering if the magnet bore could need cleaned. The lineshape looks good.
Thanks for the suggestions.
Stephanie Mabry
--------------------------------------------
Stephanie Mabry, Ph.D., Instrument Manager
University of Maryland, Baltimore County
Dept. of Chemistry and Biochemistry
1000 Hilltop Circle
Baltimore, MD 21250
office (410)455-1031
fax (410)455-2608
mabry_at_umbc.edu
Received on Mon Apr 22 2002 - 16:39:29 MST