The desire for higher magnetic resonance sensitivity has led to the development of multiple home-built and commercial dissolution dynamic nuclear polarization polarizers. The emergence of polarizers capable of variable magnetic field strengths desires a versatile standalone spectrometer and NMR circuit to fulfill detection needs at different frequencies. We present a benchtop NMR spectrometer with a duplexer capable of serving high-field solid and liquid state NMR applications up to 450 MHz. A detailed view of the employed probe is discussed. Tuning and matching schemes are investigated yielding and experimentally verifying closed-form equations to estimate the nutation frequency for a remotely tuned and matched sample coil. (C) 2019 Elsevier Inc. All rights reserved.