  The generation of high frequency oscillatory magnetic fields represents a
fundamental component underlying the successful implementation of neutron
resonant spin-echo spectrometers, a class of instrumentation critical for the
high-resolution extraction of dynamical excitations (structural and magnetic)
in materials. In this paper, the setup of the resonant circuits at the
longitudinal resonant spin-echo spectrometer RESEDA is described in
comprehensive technical detail. We demonstrate that these circuits are capable
of functioning at frequencies up to 3.6 MHz and over a broad bandwidth down to
35 kHz using a combination of signal generators, amplifiers, impedance matching
transformers, and a carefully designed cascade of tunable capacitors and
customized coils.
