Re: SIM vs QN
dave@kunmr.chem.ukans.edu
Wed, 15 Dec 1993 17:01:16 -0600
In response to Steve Philson and Kevin Gardner:
"Newer" 16-bit digitizers for AM's (freestanding boxes rather than boards
that ride piggyback on the Aspect 3000) do support simultaneous acquisition.
It has been our experience that the baselines you get, e.g. in 2D, look
different in simultaneous vs. sequential acquisition, but that simultaneous
is not necessarily better or flatter as one might expect after reading the
Felix manual. In fact, we have more artifacts such as reflections of the
diagonal in simultaneously sampled spectra, and do not routinely use it.
The problem with the appearance of sequentially sampled spectra in Felix
for Windows is really separate from that--the lack of a "bruker ft"
command as implemented in the Unix version. I have been told, but have
not confirmed, that setting the appropriate bit in the Felix header
to indicate that the data is sequential will lead Felix for Windows to
apply the bruker-type ft automatically. I would still find the explicit
command option to do the bft, overriding whatever is in the file header,
to be a considerable convenience.
As Steve indicates, zznet does not correctly handle all file
types. We have no problem with data or parameter files, but ascii files
that have been edited on a pc using a humane editor are not accepted back
by the Aspect. We don't see any problems with or changes in file size
for any file type; I assume the difficulty is more subtle but we have
never tracked it down, since we only worry about data archiving.
Dave Vander Velde, University of Kansas