Abstract: A battery charger is provided which supplies pulses of charging current to a battery and discharges the battery between each charging pulse. The change in the battery terminal voltage over a predetermined period during each charging pulse is measured, and the pulse charging is terminated when a parameter of the measured voltage change exhibits a predetermined characteristic. Pulse charging may be terminated as a result of the measured voltage change exceeding a predetermined threshold or as a result of the detection of a point of inflexion in the variation of measured voltage change with time.

Abstract: An antenna arrangement comprising a first antenna mounted on an elongate support, and a feeder cable incorporating screened and screening conductors extending longitudinally of the support from the first antenna. The screened conductor is connected to a detector of signals in a first frequency band received by the first antenna, and the screening conductor forms a second antenna connected to a detector of signals in at least one further frequency band. The first antenna may be in the form of a sleeve dipole. The support may be in the form of a tube of non-conducting material in which the first antenna is located towards one end, the feeder cable extending through the tube from the first antenna to the end of the tube remote from the first antenna.