Opera Plus FM Transmitter series cover all RF power levels from 10W up to 40kW, combining high efficiency and reliability in compact rack configurations. The consumptions are much lower compared to the previous transmitters generation. High efficiency is guaranteed at all RF output power level, through an accurate control of output power (ALC with limiter) and through an accurate control of power supply voltage calibrated with the selected output power. All RF amplifiers stages are 100% LD-MOS solid state, based on 6 th generation LD-MOS technology, providing high termal stability, simple biasing and low power supply currents.