Baseline Roll/SE451 receiver blanking on AMX500

dmcintyr@acs.ucalgary.ca
Mon, 10 Jan 1994 12:19:37 -0700

Kirk Marat writes in reference to baseline roll being caused by the receiver
opening too soon after the pulse (1.6 us) later on an AMX500 regardless of the
setting of DE:

Would anyone be willing to put a scope on their SE451 and look
at the time between the end SPFX pulse and start of the EP pulse
when GSing on an X nucleus? These signals are available on convenient
BNC jacks on the SE451.

We dragged the scope out and indeed we have the same problem on our AMX500
(CPU/3) running UXNMR version 930601.1. This seems to support Kirk's second
hypothesis, that the delay is not being calculated or set properly.

We have noticied that the baseline roll is much worse for some nuclei
(i.e. gallium) on the AMX500 than the AM400.
Cheers, Deane

Deane D. McIntyre (dmcintyr@acs.ucalgary.ca)
NMR Mananger
Dept. Biological Sciences
University of Calgary