Abstract: A radio telemetry system for collecting the readings of consumer's electricity consumption meters includes a master station (1) carried by a vehicle (1) and a plurality of transponders (3), each of which holds an electrical quantity indicative of an amount of electrical power consumed as measured by the meter associated with that transponder (3). The transponders (3) and the master station (1) communicate such that the transponders (3) transmit to the master station (1) signals containing information as to the values of the aforesaid electrical quantities held by them. Such communication takes place on a relatively quiet channel, of a number of channels, as determined by the master station (1) such that the system is capable of operating satisfactorily when the master station (1) and the transponders (3) utilise relatively low power transmitters (7, 19).