2.8 Example 1: aquiring a 1-pulse spectrum step-by-step

Ok, sample in the probehead, tunned and mached? Then, open a unix terminal and type (if Vnmr(J) is not yet open)

vn &

to open Vnmr in background (Section 0.3), or

vnmrj &

to open VnmrJ in background, or

double click the Vnmr(J) icon.

Inform yourself about the maximum power for your probehead. Then check it with tpwr? and tpwrm?. If tpwrm does not exist, then it is equivalend to setting it to the maximum (normally the max is tpwrm=4095). Then type

jexp1 s2pul sw=100000 pw=3 p1=0 d1=1 at=2 nt=1 ss=0 lsfid=0 pad=0 array?

The answer should tell there is no array. Then do ga, wait the expt finish and type ft full f dc vsadj. Is there a signal anywhere in your expectrum? Then the instument is working :-)

Now select with left-click write-click a new spectral window with the signal plus some border and type movesw ga. Now phase your spectrum (see Section ). Type wti in order to see your spectrum, apodization function, and FID in one window. Midle-click the top sub-window to ajust the spectrum intensity, and the lowest sub-window to ajust the FID intensity. Now left-click the midle sub-window to ajust the apodization function (lb value). You will see the spectral linewidth changing accordingly on the top sub-window.

Ajust lb and type comwft, left-click one non-overlaping line and type nl res. From the linewidth and shape you have an idea about your shims. See Section 2.3 to shim it better.