Repeaters allow us to communicate over large areas. Repeaters are usually located at higher elevations to increase coverage. When you transmit from your radio to a repeater, the signal is sent out to its coverage area. The difference in frequency of the incoming transmission and the outgoing re-transmission is called the "offset".
In addition to the offset, repeaters also require a sub-audible tone or carrier signal to unmute the repeater to the incoming signal. These sub-tones are called PL (Private Line) or CTCSS (Continuous Tone-Coded Squelch System) tone. Many repeaters are public and the offset and CTCSS tone are readily available (ie: RepeaterBook™). Many newer radios already have correct offsets programmed for each frequency.
Simplex operation of your radio is similar to using a walkie-talkie. It has a limited range and requires good line-of-sight in order to be able to reach the receiving station. It's important to know how to operate in simplex mode in case a repeater is not available.
Use of a repeater allows us to communicate with many communities. Our La Honda repeater (146.730, minus offset, 114.8 PL tone) connects the communities of South Skyline, parts of Woodside, La Honda, Middleton Tract, Waterman Gap, Alpine Rd, San Gregorio, Loma Mar, and Pescadero. Depending on your antenna and radio, you may reach our repeater from Gazos Creek, Half Moon Bay and even locations on the Bayside!