A method, device and system for reducing the number of feeders (2, 3) between a radio base station (1) and an antenna diversity arrangement (10, 11, 12, 13) at which RF signals of the same frequency are received. In a tower mounted amplifier (45) individual RF signals from some or all of the antennas are frequency converted into intermediate frequency (IF) signals on mutually different intermediate frequencies which are combined and forwarded to the radio base station on a reduced number of feeders. In the radio base station the combined signal is split into individual signals amongst which the IF signals are frequency transformed to a signal suitable for diversity processing.