Abstract: A tower mounted amplifier filter for use in mobile base station antenna masts comprising three TMA filter functions, two reception path filters separated by a low noise amplifier and one transmission path filter, implemented by means of coaxial resonator cavities, two of them being common resonators where the receive and transmission paths are combined in two output/input ports for connection with external devices, the body housing of the filter being made of thermoplastic material with high content of glass- and mineral-fillers, and coated with an electrical conductive material.