Hi all,
after some trouble we got XWIN-NMR 3.1 for SuSe-Linux 8.0
running. Not supported, but it seem to work.
Nevertheles there is one remaining serious problem and I hope
this is not due to that special Linux distribution.
The problem itself:
If one uses old date sets taken from the former SGI
computer all works fine - nearly fine. After procesing the
data you see that all proton shifts are moved about
60 Hz downfield. Under some special circumstances (DQD,
DW=40.4 us, DWOV=2.525 us) this shift is even larger (about
190 us). This part is the minor problem only and easy
to correct using the calibration procedure. But unfortunately
the absolute frequencies are shifted too. If you try to
read an SFO1 from a given peak this is wrong by the
already mentioned 60 Hz. For the setup of water suppression
sequences this is deadly. You don't hit the water signal!
The problem itself apparently already happens during the
acquisition. I tried to transfer an acquired spectrum before
the processing to our old SGI machine and got the same effect
after the processing there.
Is this frequency shift our problem only, or did you made
comparable observations? If you don't setup water
suppression experiments you will not observe this effect
with a high probability. To check it out, simply choose one
signal within your spectrum, define SFO1 to have that signal
on resonance, transform and observe the position of the signal.
Is it in the center of the spectrum or slightly moved
downfield?
I would be very happy to kmow your observations.
Best regards
Rainer
TU Munich
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Received on Fri Jul 19 2002 - 13:19:45 MST