The amplifiers are linear, robust and deliver a shape-retaining, low harmonic signal. The stability of the amplifier is of great importance for use in spectroscopy. The amplifiers of the RFPA-4U series are therefore both amplitude-stable and phase-stable. Essential for the application are short RF drop times and short pre-gating times. We have realized that. The amplifiers can be remote controlled via a serial interface. Corresponding software is included in the scope of delivery.