 2H_pwxcal

  Alex Eletsky, SUNY at Buffalo, March 2008

  Parameters:

        pw = 90 degree excitation pulse on the observe transmitter (C13)
        pwx3 = 90 degree excitation pulse on third decoupler (H2)
        jCD = J(C13-H2) coupling constant (24.2 Hz for C6D6)
        anti = 'y' or 'n' selects in-phase or antiphase triplet
        lkflg = 'y' or 'n' turns lock gating on and off. Default 'y'

1.  Set anti='n' to record an in-phase 13C triplet.
    Calibrate pw and move tof to the center line.
    Measure J(C13-H2) and set jCD to this value.
2.  Set anti='y' pwx3=0. Record a 1D spectrum.
    You should see outer lines antiphase, and the middle line is absent.
    You may further adjust pw to completely suppress the middle line.
3.  Set dof3 and dpwr3 (usually ~40 dB, see the specifications for your
    instrument). Set dm3='nnn'
    Array pwx3 and observe the zero crossing for the outer lines -
    this will be the 90-degree pulse on 2H
4.  Test decoupling by setting anti='n', dm3='nny', dmm3='ccw', dmf3=1/pwx3,
    where pwx3 is the calibrated pulse width. You should see the
    triplet collapse into a singlet
