An NMR spectrometer (131) with an NMR magnet coil (91) having windings of a conductor with a superconducting structure (1), which have a plurality of band-segments (2, 2a, 7a-7e, 8a-8d, 15) made of band-shaped superconductor. Each band-segment (2, 2a, 7a-7e, 8a-8d, 15) has a flexible substrate (3) and a superconducting layer (4) deposited thereon, wherein the band-segments (2, 2a, 7a-7e, 8a-8d, 15) each have a length of 20 m or more. At least one of the band-segments (2, 2a, 7a-7e, 8a-8d, 15) forms a linked band-segment (2, 2a), and each linked band-segment (2, 2a) is connected to at least two further band-segments (7a-7e) in such a way that the combined further band-segments (7a-7e) overlap with at least 95% of the total length (L) of the linked band-segment (2, 2a). The magnet coil generates particularly high magnetic fields in a sample volume and has a low drift.