Dear NMR experts,
Here at UW-Madison Chemistry we've been successful keeping a couple of
old Bruker AC 300 NMR spectrometers alive. Unfortunately one of the
"bit the dust" this week, and we've been troubleshooting to get it back
up and running. Fortunately we have a decommissioned AC 250, which we
can use for spare parts (non-freq specific of course).
Hopefully we can get some advice from folks in this community. We have
essentially lost detection on the imaginary channel, thus all our
spectra have major quad artifacts. If when looking at the FID, we split
the screen into the Real and Imaginary channels (ctrl-Y command), we see
a fid on the left side (real), but just a flat line on the right side
(imaginary). If we run 8 scans, for the first 4 scans there's just a
flat line on the right side (and it moves up, then down with scan
number), while the next 4 scans show a fid on the right side (which also
shifts with scan number). Throughout the duration of the 8 scans, there
is a fid on the left side (real).
We have swapped out both the analog-to-digital converter board and the
memory board in the Aspect 3000 computer, without success. We have also
swapped out the receiver, but still see the same thing. What else could
we/should we try? Any advice would be gratefully appreciated.
Cheers,
Monika
--
Monika Ivancic, PhD
Associate NMR Director
Department of Chemistry
University of Wisconsin
1101 University Ave.
Madison, WI 53706-1396
(608)262-7536
fax (608)262-0381
e-mail ivancic_at_chem.wisc.edu
Received on Wed Jun 13 2012 - 10:12:12 MST