Hello everyone,
I am having problems to get a good 3D gradient shim map on a Bruker
Avances DRX600. The 3d shim map is very noisy and of course 3d gradshim
doesn't work. The FIDs of the failed experiments under 'gradshimdata'
are either saturated or missing some gradient echos in the two channels.
This happens to both TXI and TBI probes. Reducing the receiver gain
doesn't help.
So far we have replaced HADC/2, RX22, RCU, TCU, GCU, FCU1/FCU2 and
gradient amplifier, but no luck. AT one time we did get a good 3d shim map
for the TXI probe (after many attempts) and 3d gradshim works fine using
this reference map. But attempts to reproduce the results failed. Triple
resonance 3d experiments works just fine. The probes are very good ones,
and I don't have any problems to reproduce the specifications (lineshape,
sensitivity etc). It seems to me the problem is somewhere in the console.
Does anyone have similiar probelm? Your opinion is greatly appreciated.
Thanks,
Huadong
-----
Huadong Zeng
NMR Core Facility
University of Alabama at Birmingham
933 19 St. S. CH19 B31
Birmingham, AL 35294
Tel: (205)934-5696 or 9345697
Fax: (205)934-6475
Email: huadong_at_schubert.nmrcore.uab.edu
Received on Tue Oct 16 2001 - 17:48:54 MST