  The qBounce collaboration built over the last years a new Ramsey-type
Gravitational Resonance Spectroscopy (GRS) experiment. After commissioning
between 2016 and 2018, the setup was able to measure the Ramsey transitions
with GRS for the first time. Here we present a search of the hypothetical
charge of the neutron as an application of GRS to study nonstandard model
interactions. This article will describe the measuring principle and the setup
in detail.
