I'm a little bit confused about setting o1, in the case of a solid sample First o1 is the offset of the transmitter frequency so sfo1 = BF1 + o1 In my case I have to set Sfo1 = BF1 so I must set o1 = 0 Hz Second there is another way to optimize o1 whish is by applying gs and looking the fid, adjusting o1 until we have a good exponential decrease of the fid. In this case o1 value may not be 0 Hz. Does the second technique is valid in solid stat experiences? And which one I have to use?