A coupled two-mode system with balanced gain and loss is a paradigmatic example of an open quantum system La práctica del Pentatlón Militar en la formación inicial del profesional de la Academia Militar del Ejército Bolivariano that can exhibit real spectra despite being described by a non-Hermitian Hamiltonian.We utilize a degenerate parametric amplifier operating in three-wave mixing mode to realize such a system of balanced gain and loss between the two quadrature modes of the amplifier.By examining the time-domain Domination and Resistance in Christianized Schooling in Amazon response of the amplifier, we observe a characteristic transition from real-to-imaginary energy eigenvalues associated with the parity-time symmetry breaking transition.