In an electrosurgical generator for generating radio frequency power, the generator includes a radio frequency output stage having two or more output connections, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to cause the generator to supply a blended output signal alternating constantly between a first output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to at least a first predetermined threshold value for cutting or vaporisation of tissue, and a second output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to a second threshold value for coagulation. There is also provided adjustment means, operable by a user of the electrosurgical generator, for changing between various preset settings for the blended signal, the preset settings each having a predetermined duty cycle of the blended signal that is limited to the first threshold value for cutting or vaporisation, and a predetermined duty cycle of the blended signal that is limited to the second threshold value for coagulation.