> AMX-600: Calibration of the proton pulse is asymmetric. For ex: if HL1=3
> and using PAROPT with p1 starting at 1u and incremented by 1u for 32
> increments. The 90 maximum is reached early at about 8u and 180 is at
> about 20u. The pulse width I usually get is 10u for 90 pulse. I see this
> at all different power levels of the proton e-coupler. It is really bad
> at low power levels like HL1=40 for a 1ms pulse for saturating water in
> watergate sequence. The 90 I get in the last case is at about 700u
> instead of 1000u, but 180 is at 2000u. I have tried everything. Please
> help.
What is your recycle time and what sample? It sounds like you are not waiting
long enough between scans/experiments. For this type of callibration you
really do need to wait at least 7 * T1. If it is a simpe water based sample D0
= 30 s may be acceptable but for a degassed chloroform or acetone sample
several minutes will be needed.
Hope this helps,
Graham Barlow
--/ Dr. Graham Barlow, NMR Service Manager \ / gkb1@york.ac.uk \ [ Dept. of Chemistry, Univ. of York, York, UK ][ Tel: 01904 432506 ] [ http://www.york.ac.uk/depts/chem/nmr ][ Mobile: 0402 181253 ] \ http://www.york.ac.uk/~gkb1/ / \ Fax: 01904 432516 /