Many thanks to those who responded to my last question concerning
calibration of a shaped pulse on the decoupler channel of our AMX
spectrometer. The problem turned out to be a short circuit between my ears
as usual. I had everything set up ok except that the 1H transmitter pulse
was not on resonance. Once that was fixed everything worked fine.
My next problem concerns how to determine the phase difference between
the decoupler shaped pulse and a decoupler hard pulse. I'm using a simple
modification of my successful shaped pulse calibration program (again,
thanks to those who assisted in this area) but as usual, it isn't doing
what I think that it should. Here it is:
1 ze
2 d1 dlo hl1
p1 ph1
d2 hl2
(p3 ph3):d
(p4 ph4:r):dp1 (p2 ph2):f1
go=2 ph31
wr #0
exit
ph1-0
ph2=0
ph3=0
ph4=0
I first do a spectrum with p3 set to zero and dp1 set at 70db and phase
correct the resulting antiphase doublet. Then I set dp1 to the 90 degree
shaped pulse power that I have calibrated, set p3 to a 90 degree low
power decoupler pulse width and do a paropt, varying phcor[4] to vary the
phase angle of the shaped pulse. I look for the oppositely phased
antiphase doublet but see only what I would see if p3 were zero. In other
words it looks as though there is only a 90 degree shaped pulse being
applied. My question is: should p3 be a high power decoupler pulse and if
so, how long should the switching delay be? I would have to switch to high
power for the hard pulse and back to low power for the shaped pulse,
right?
Keith Brown
University of Saskatchewan
Saskatoon, Saskatchewan
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100 buckets of bits on the bus
100 buckets of bits
Take one down, short it to ground
FF buckets of bits on the bus
FF buckets of bits on the bus
FF buckets of bits
Take one down, short it to ground
FE buckets of bits on the bus
ad infinitum...
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