A broadband RF Spectrum Transmitter combiner is duplexed with a Receiver splitter/multicoupler through a unique circulator/isolator configuration to provide a bi-directional radio input, unidirectional input at the receiver multicoupler to the radio and a unidirectional output from the radio to the transmitter combiner output. The circulator/isolator duplexer circuitry may be configured for any RF frequency band and in conjunction with the use of a same frequency band transmit combiner and receiver multicoupler provide the cohabitiation of mobile radios with isolation is excess of 60 dB. The multiple ports may be connected to multiple radio units, each with a different frequency, and combined and connected to a transmit antenna and a receive antenna. The duplexer-combiner configuration is used then to combine the bi-directional antenna port on the radios into a pair of antennas spaced apart from one another as to not degrade the isolation provided by the duplexer-combiner configuration.