¹H acquisition with broadband X-decoupling is a normal situation in inverse ¹H-X detected experiments of natural abundance and isotopically enriched compounds. Thus during ¹H acquisition, decoupling of X (¹³C, ¹⁵N ...) is performed from an independent channel using a composite pulse decoupling (CPD) scheme as, for instance, GARP, WURST .... (see decoupling schemes).

Easy implementation on AVANCE spectrometers.

 For more experimental details see Tutorials: Calibration pulses.

The most standard way to implement an heteronuclear decoupling is:

... 2 d1 do ... d12 pl12:f2 go=2 ph31  cpd2:f2 ... d12 do:f2 ...

in which:

• go starts data acquisition during an acq period using the acquisition parameters previously defined in eda.
• Broadband heterodecoupling is performed at low power (pl12) from the f2 channel using the cpd2:f2 command. The composite pulse decoupling scheme to be applied is defined by the acquisition parameter cpdprg2 (for instance, garp) and the decoupling conditions are defined by pcpd2 (90 pulse at pl12). See, for instance, low-power ¹³C 90 pulse calibration for GARP.
• The number after go (=2) defines the loop to be executed. The number of times this loop is repeated is governed by the number of scans (ns).
• ph31 is the receiver phase specified at the end of pulse program and must be cycled in accordance to all pulses involved in the pulse sequence.
• Heterodecoupling is stopped using the do command.