An electrical generator arrangement comprising a distribution network having a first generator and a second generator, the first generator arranged to provide electrical power to a transmitter source, the second generator coupled to the distribution network by a switch to enable isolation of the second generator, the switch associated with an electrical characteristic comparator to compare the phase and/or frequency of the voltage provided by the second generator with the incidental modulation of a transmitter signal from the transmitter due to variations in the phase and/or frequency of the voltage provided by the first generator to the transmitter, the comparator arranged to operate the switch to isolate or connect the second generator to the distribution network dependent upon a variation in the change of the phase and/or frequency of the voltage provided by the second generator and the incidental modulation of the transmitted signal.