Dear BUMers,
I need your kind help.
I met a very strange problem when running a 1D WATERGATE experiments.
The system configuration is:
Spectroscopy: Bruker Avance DMX 600
Xwin-nmr: ver 1.3 patchlevel 9 on IRIX 5.3
Probehead: 5mm TXI 13c 15n XYZ
Preemphasis: ACUSTAR for shielded X-Y-Z-gradients
Pulseprogram: zg3919, see the end part of this email.
The problem appears as:
First I create a new dataset from an existing successful 1D Watergate
dataset (sw=20ppm, rg=128) with the command 'iexpno' or 'edc'.
Then I run 'rga' without change anything, the results seems ok, it gives
rg=128 after several seconds or so.
Now I change the sw to a smaller or bigger value, say, from the original
20ppm to 12ppm, and run 'rga' again, the message "signal too weak with
RG=1.0" appear in a pop-up dialog box. If I change the sw back to 20ppm,
run 'rga', the message still appears! Seems it remembered the sw was
once changed!
Now if I create another dataset from that successful one. Things are the
same, i.e. 'rga' runs ok if I didn't change the sw, but gives the
message if sw was changed. It seems it doesn't matter if I change p1, o1
( other parameter not tested).
The pulseprogram is from NMRFAM but it should be similiar to other 1d
Watergate pulseprogram.
;zg3919
;1D sequence
;p1 90 1H at pl1
;d21 = 1/((8.0-4.7)*bf1*2), 250us for 600M
;grdprog: zg3919
;p17 700u
;cnst23 40
;
define delay TAUW
"d13=5u"
"d14=20u"
"d16=300u"
"TAUW=d21"
#include <Avance.incl>
#include <Gradfa.incl>
1 ze
2 d14 LOCKH_OFF
d1 pl1:f1
d14 LOCKH_ON
p1 ph11
d13
GRADIENT17(cnst23) ;700u, 40G/cm magic angle cnst30
d16
(p1*0.231 ph12):f1
TAUW
(p1*0.692 ph12):f1
TAUW
(p1*1.462 ph12):f1
TAUW
(p1*1.462 ph13):f1
TAUW
(p1*0.692 ph13):f1
TAUW
(p1*0.231 ph13):f1
d13
GRADIENT17(cnst23) ;700u, 40G/cm
d16
go=2 ph31
wr #0
d14 LOCKH_OFF
exit
ph0=0
ph1=1
ph2=2
ph3=3
ph11=0 2 1 3
ph12=1 3 2 0
ph13=3 1 0 2
ph31=0 2 1 3
;------end of pp--------
In the Gradfa.incl, this line concerns
#define GRADIENT17(ampl) p17:ngrad:c34
The grdprog is:
p17 { (0)+(cnst23*cnst30) | (0) | (0)+(cnst23) }
{ (0) | (0) | (0) }
p17 { (0)+(cnst23*cnst30) | (0) | (0)+(cnst23) }
{ (0) | (0) | (0) }
-- Yu-Feng Tong||童宇峰 NMR Group, Dept. Enzymology Inst. Biophysics, Academia Sinica 15 Datun Road, Beijing, P.R.China, 100101 mailto: baseline@sina.com _______________________________________________________________________________ Life is an everlasting game of gamble.
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