Setting Sr to zero will get your scales correct but if your spectral width
is still 400 ppm this appears that in0 and or inf are being miscalculated
in some way.
Your data shows the correct value for the inf for a 200 ppm. But if your
actual spectral width in the Si dimension is actually twice as big then inf
is being divided by 2.
Check your pulse sequence there should be a statement in0=inf/2 just above
the ze statement on line. Because there are 2 d0s and total increment needs
to be inf.
If is is something else that is your error.
Older versions of topspin 2.1 and below used the nd0 parameter. Assuming
you are not using that.
David
Associate Professor
Dept. Of Pharmacology
University of Colorado
School of Medicine
Tel (303)-724-3600
On Apr 18, 2026, at 9:01 AM, Akien, Geoffrey via groups.io wrote:
Hi Ted,
If you adapted the HMBC parameter set from another nucleus, the usual
candidate is 1 SR being set to some unreasonably large value. Set it
to zero and wpar the parameter set so its correct for the next time
you use it.
Thanks
Geoff
________________________________
> From: main_at_ammrl.groups.io on behalf of Wiessner, Tedd via groups.io
> Sent: 17 April 2026 18:40
> To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
> Subject: [External] [AMMRL] Silicone-HMBC help
Hi All,
We are trying to implement a silicon-HMBC experiment and are having trouble
getting the Si-axis to be in the range we want.
The sweep width we were going for was 200 ppm centered at -40 ppm, but the
spectra we keep getting are labeled as ranging from 960,777 to around 960,384 ppm
(SW~400 ppm). Does anyone have any ideas why this is happening and how to fix
it? I feel like I am missing something simple but am at a loss.
For reference, the spectrum below is of tetraethoxy silane (~-81.8 ppm).
Thanks!
Best,
Tedd
Tedd C. Wiessner, PhD
Senior Scientist I, Pathways Manager, Analytical Lab | H.B. Fuller Company
1200 Willow Lake Blvd | Vadnais Heights | MN | 55110 | USA
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Received on Sat Apr 18 2026 - 09:28:57 MST