Interference from FM Radio Stations

FM radio stations transmit their signals at frequencies close to 100 MHz. Unfortunately this frequency is coincident with the resonance frequencies of several NMR active isotopes at commonly available magnetic field strengths. Under some circumstances, FM radio signals can interfere with NMR measurements. The figures below are solid state ²⁷Al and ⁶⁹Ga QCPMG NMR spectra taken in Windsor, Ontario in a 9.4 Tesla magnet. Both examples show interference from local FM radio stations. In the case of the ⁶⁹Ga, no NMR signals are observed.Thank-you to Joel Tang and Robert Schurko from the Department of Chemistry and Biochemistry at the University of Windsor for providing the data for this post.