Inductive coupling and tuning of NMR probes is ideally suited for certain applications because no direct electrical connections to the resonant circuit are required. The relatively transparent case of series-tuned link coupling is analyzed. It is shown that tuning and coupling adjustments are orthogonal and that most of the RF field comes from the main circuit, not the link. Applications of inductive tuning and coupling are suggested; including low-temperature NMR where Dewar space is restricted. An experimental comparison of conventional, link-coupled, and link-coupled and tuned circuits at 85 MHz is reported. Some novel VHF self-contained resonators are discussed and their performance is experimentally compared to conventional coils.
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We are grateful to J. J. H. Ackerman for helpful discussions. J. Schaefer is appreciated. This work was partly supported Petroleum Research Fund, administered by the American The encouragement through the generosity Chemical Society.