A pinion gear type rotating device, in particular, is used in electromagnetic interference characterization of a fiber optics transceiver, by which a member, such as a fiber optics transceiver can be held and rotated by at least 360 degrees about x, y and z axes. The device comprising a first support structure for being rotated about the first axis, a first shaft which extends along said first axis and to which a second support structure is connected via a first pinion gear train 140 for being rotated about the second axis extending across the first axis, the second support structure and first pinion gear train 140 being arranged on the first support structure for being rotated therewith, and second shaft which extends along the said first axis and to which a third support structure on which the member is to be arranged, is connected via second and third pinion gear trains 150, 160 for being rotated about the third axis extending across the second axis, the third support structure and the third pinion gear train 160 being arranged on the second support structure for being rotated therewith, and the second pinion gear train 150 being arranged on the first support structure for being rotated therewith and for transferring a rotation of the second shaft to a rotation about the second axis.