When two radios communicate directly with eachother, this is known as Special stinless steel screw Simplex. To achieve greater range, a radio repeater isoften utilized.  Each portable radiocommunicates with the repeater and the repeater rebroadcasts the signal for theother portable.A Repeater is a device which will receive asignal on one frequency and re-transmits the signal with increased strength onanother frequency simultaneously in a two-way radio communication.

Transmissions are received from portable two way radios by the repeater andthen are broadcast at a much higher wattage on a different frequency. Repeater is nothing new to amateur radio (HAM)operators and they all know that it uses different transmitting and receivingfrequencies. Setting up the radio to repeater-mode is no big deal but with FRSradios repeater-mode is not implemented at all.In general, repeater systems are usuallylocated in places of high elevation (on tall towers, on top of mountains ortall buildings) and are equipped with large and efficient antennas, extremelylow loss feedlines, and a transmitter and receiver that is very durable, ratedfor continuous duty, and built to be as immune as possible to interference.For a radio to be repeater capable, it mustsupport having different transmit and receive frequencies for the same channel.Frequencies used for repeater communications are typically not standardbuilt-in frequencies, so repeater capable radios are usually "fullyprogrammable".As we all know, longer the distance a signalmust travel, weaker it gets. This phenomenon is called signal attenuation.Repeaters are very essential since it boosts the signal power and reducessignal attenuation drastically during radio communication.A repeater "gets out" your signal andreceives the station you are talking to with a far greater range and coveragearea!

Repeater systems are used to "transfer" your transmitted andreceived signals to much higher elevations electronically using large, veryefficient antennas, low loss feedlines and a transmitter and receiver that israted for heavy or continuous duty.In order to listen and transmit at the sametime, repeaters use two different frequencies. One is for transmittingfrequency and another for receiving frequency. This is referred to as offset.Without having an offset between the transmit signal and the receive signalfrequency, the repeater would simply hear itself when it was transmitting onthe same frequency it was listening on! Repeaters are used in cellular communication tohandle the hand-off concept, when the user moves out of one cell to anothercell. This helps the user to receive a proper signal by making sure that thesignal level does not drop.Radiorepeaters are allowed on Amateur (HAM), GMRS (General Mobile Radio Service),and Business Band. Radio repeaters are not allowed on CB (Citizens Band), FRS(Family Radio Service), or MURS (Multi-Use Radio Service).