Taking into account the enhanced demand for 4 and 8 channel trunking systems a combiner has been worked out on the basis of four-resonator monoblock that is mounted at 19" stand. This has allowed to optimize the ratio volume/Q-factor for 19-inch construction solution. The combiners TETRA-A (at 300-360 MHz) and TETRA-U (at 400-490 MHz) represent a good solution for constructing base stations of the same name standard.