Dear Joseph Vaughn,
Are the phase tables used in both experiments the same? It may be
possible that one ot your acquisition or transmitting phase switching
schemes are misbehaving in one of the experiments and leading to a
canceled signal for multiple scans.
Joseph Vaughn wrote:
> Colleagues
>
> We have recently encountered the following odd behavior on our
> Inova500 solid state spectrometer. We can do cpmas 1 pulse
> observation of Se, for example. We observe a perfectly normal
> spectrum with nt=1, or 2 or 3 or 4 or any multiple of those. If we
> set tn=13C and make no other parameter change (sw is sufficient)and
> nt=1 with Hexamethylbenzene, we observe a normal 13C spectrum.
> However, if we set nt=4 or nx4 we get nothing but noise.
>
> Has anyone else seen such behavior? Does anyone have some suggestion
> about the problem?
>
> Thanks
>
> Joseph Vaughn
>
>
--
Francis Picart
NMR Coordinator
Department of Chemistry
State University of New York at Stony Brook
Room 507
Stony Brook, New York 11794-3400
(631)632-7991
Received on Mon Jul 12 2004 - 10:46:51 MST