It was quite a while since I posted this question, and perhaps I should
let you know of the outcome (better late than never !)
The original problem was that when we tried inverse mode detection on a
Bruker AC250 with Tecmag upgrade, the phase of the FID was arbitrary. It
turns out that the O2 and receiver phases are not synchronized on AC
instruments.
Many people suggested various (hardware) fixes for
that problem. However, we opted for the approach that avoided the
problem in the first place. Tecmag console has two levels for the
transmitter power, LOW and HIGH. While in the HIGH mode a significant
pulse droop occurs, the pulse power is stable when the transmitter is in
the LOW mode. So, we are using the transmitter in LOW with a good amplifier
rather than the decoupler.
Thanks to everyone who replied !
Konstantin Momot
Group of C. S. Johnson, Jr., UNC Chapel Hill
Ph.: (919)-962-7576
FAX: (919)-962-2388
momot@u.arizona.edu
http://www.u.arizona.edu/~momot/research.html