Glenn,
When you operate an AM unlocked (with field sweep off) the drift
compensator is engaged. The drift compensator increment size is set by
the "LOCK DC" parameter on the SCM (shift/SPIN RATE). If this value is
set by the knob to zero, there is no compensation. If your magnet
drifts, this increment value can be set empirically to correct for the
drift. When the Z0 compensation DAC reaches its maximum code, the alarm
will sound, as for other parameters which are cranked too far. If the
paramerer is set to zero and the alarm still sounds when you run
unlocked, there is some sort of problem. Good luck...
Ben Bangerter
*******************
Glenn Facey wrote:
>
> Dear members
>
> Recently while running some NMR experiments unlocked on my
> AMX-500 spectrometer, I have been getting an alarm and error
> signal on by SCM unit. The display reads error 0008. According to
> the manual this error is due to "drift DAC overflow". The NMR
> experiments continue to run happily however the alarm is quite
> annoying. What is the cause of this? and how can I fix it?
>
> Glenn A. Facey
> NMR Facility Manager
> University of Ottawa
> mailto:gafacey_at_science.uottawa.ca
> http://www.science.uottawa.ca/~nmr
Received on Tue Sep 12 2000 - 11:32:18 MST